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Sample records for boron doped diamond

  1. Characterization of boron doped nanocrystalline diamonds

    Energy Technology Data Exchange (ETDEWEB)

    Peterlevitz, A C; Manne, G M; Sampaio, M A; Quispe, J C R; Pasquetto, M P; Iannini, R F; Ceragioli, H J; Baranauskas, V [Faculdade de Engenharia Eletrica e Computacao, Departamento de Semicondutores, Instrumentos e Fotonica, Universidade Estadual de Campinas, UNICAMP, Av. Albert Einstein N.400, 13083-852 Campinas SP Brasil (Brazil)], E-mail: vitor.baranauskas@gmail.com

    2008-03-15

    Nanostructured diamond doped with boron was prepared using a hot-filament assisted chemical vapour deposition system fed with an ethyl alcohol, hydrogen and argon mixture. The reduction of the diamond grains to the nanoscale was produced by secondary nucleation and defects induced by argon and boron atoms via surface reactions during chemical vapour deposition. Raman measurements show that the samples are nanodiamonds embedded in a matrix of graphite and disordered carbon grains, while morphological investigations using field electron scanning microscopy show that the size of the grains ranges from 20 to 100 nm. The lowest threshold fields achieved were in the 1.6 to 2.4 V/{mu}m range.

  2. Piezoresistive boron doped diamond nanowire

    Energy Technology Data Exchange (ETDEWEB)

    Sumant, Anirudha V.; Wang, Xinpeng

    2016-09-13

    A UNCD nanowire comprises a first end electrically coupled to a first contact pad which is disposed on a substrate. A second end is electrically coupled to a second contact pad also disposed on the substrate. The UNCD nanowire is doped with a dopant and disposed over the substrate. The UNCD nanowire is movable between a first configuration in which no force is exerted on the UNCD nanowire and a second configuration in which the UNCD nanowire bends about the first end and the second end in response to a force. The UNCD nanowire has a first resistance in the first configuration and a second resistance in the second configuration which is different from the first resistance. The UNCD nanowire is structured to have a gauge factor of at least about 70, for example, in the range of about 70 to about 1,800.

  3. Technology for boron-doped layers formation on the diamond

    Directory of Open Access Journals (Sweden)

    Zyablyuk K. N.

    2012-10-01

    Full Text Available The authors investigated natural type IIa diamond crystals and CVD diamond films. The article presents electrophysical parameters of the structures obtained in different modes of ion implantation of boron into the crystal with further annealing. Parameters of the crystals with a high nitrogen impurity density indicate that they can be used for the manufacture of microwave field-effect transistors operating at room temperature. CVD diamond films doped with boron during the growth process also have the required for MOSFET manufacture carrier mobility. However, due to the high activation energy of boron, the required channel conductivity is achieved at high operating temperatures.

  4. Electrochemical synthesis on boron-doped diamond

    International Nuclear Information System (INIS)

    Boron-doped diamond (BDD) is a novel and innovative electrode material. In protic media and particular aqueous electrolytes BDD exhibits a large over potential for the evolution of molecular hydrogen and oxygen. The large chemical window allows a variety of electrochemical conversions to be conducted. The anodic process treatment generates oxyl species directly which are known to be extremely reactive. Usually, the electrochemical mineralization of the organic components in the electrolyte occurs. However, with control of the reactivity of these intermediates the use in electroorganic synthesis can be realized. Until today mostly anodic conversions have been studied at BDD. Since hydroxyl radicals can be efficiently formed and exhibit an enormous oxidative power they are exploited for the electroorganic synthesis. In general, two strategies can be applied to circumvent electrochemical incineration: First, the substrate serves as solvent and partial conversion exploits statistics to gain selectivity for the desired product. This particular approach is useful when the excess of substrate can subsequently be evaporated, and is readily available and inexpensive. The second strategy uses fluorinated alcohols as additives which enlarge the chemical window. The specific role of these fluorinated solvents can be attributed to the stabilization of hydroxyl or methoxyl radicals by supramolecular taming of these intermediates. Moreover, these additives paved the way to the first anodic phenol–arene cross-coupling reaction.

  5. Boron-doped superlattices and Bragg mirrors in diamond

    OpenAIRE

    Fiori, Alexandre; Bousquet, Jessica; Eon, David; Omnès, Franck; Bellet-Amalric, E.; Bustarret, Etienne

    2014-01-01

    International audience A periodic modulation of the boron doping level of single crystal diamond multilayers over more than three orders of magnitude during epitaxial growth by microwave plasma-enhanced chemical vapor deposition is shown to yield Bragg mirrors in the visible. The thicknesses and doping level of the individual layers were controlled by in situ spectroscopic ellipsometry, enabling to tune the reflec-tance peak to the wavelength range of diamond color centers, such as NV 0 or...

  6. Electrical Characterization of Diamond/Boron Doped Diamond Nanostructures for Use in Harsh Environment Applications

    Science.gov (United States)

    Gołuński, Ł.; Zwolski, K.; Płotka, P.

    2016-01-01

    The polycrystalline boron doped diamond (BDD) shows stable electrical properties and high tolerance for harsh environments (e.g. high temperature or aggressive chemical compounds) comparing to other materials used in semiconductor devices. In this study authors have designed electronic devices fabricated from non-intentionally (NiD) films and highly boron doped diamond structures. Presented semiconductor devices consist of highly boron doped structures grown on NiD diamond films. Fabricated structures were analyzed by electrical measurements for use in harsh environment applications. Moreover, the boron-doping level and influence of oxygen content on chemical composition of diamond films were particularly investigated. Microwave Plasma Enhanced Chemical Vapour Deposition (MW PE CVD) has been used for thin diamond films growth. Non-intentionally doped diamond (0 ppm [B]/[C]) films have been deposited on the Si/SiO2 wafers with different content of carbon, boron and oxygen in the gas phase. Then, the shape of the highly doped diamond structures were obtained by pyrolysis of SiO2 on NiD film and standard lithography process. The highly doped structures were obtained for different growth time and [B]/[C] ratio (4000 - 10000 ppm). The narrowest distance between two highly doped structures was 5pm. The standard Ti/Au ohmic contacts were deposited using physical vapour deposition for electrical characterization of NiD/BDD devices. The influence of diffusion boron from highly doped diamond into non-doped/low-doped diamond film was investigated. Surface morphology of designed structures was analyzed by Scanning Electron Microscope and optical microscope. The resistivity of the NiD and film was studied using four-point probe measurements also DC studies were done.

  7. Note: Novel diamond anvil cell for electrical measurements using boron-doped metallic diamond electrodes.

    Science.gov (United States)

    Matsumoto, R; Sasama, Y; Fujioka, M; Irifune, T; Tanaka, M; Yamaguchi, T; Takeya, H; Takano, Y

    2016-07-01

    A novel diamond anvil cell suitable for electrical transport measurements under high pressure has been developed. A boron-doped metallic diamond film was deposited as an electrode on a nano-polycrystalline diamond anvil using a microwave plasma-assisted chemical vapor deposition technique combined with electron beam lithography. The maximum pressure that can be achieved by this assembly is above 30 GPa. We report electrical transport measurements of Pb up to 8 GPa. The boron-doped metallic diamond electrodes showed no signs of degradation after repeated compression. PMID:27475610

  8. Thermal diffusion boron doping of single-crystal natural diamond

    Science.gov (United States)

    Seo, Jung-Hun; Wu, Henry; Mikael, Solomon; Mi, Hongyi; Blanchard, James P.; Venkataramanan, Giri; Zhou, Weidong; Gong, Shaoqin; Morgan, Dane; Ma, Zhenqiang

    2016-05-01

    With the best overall electronic and thermal properties, single crystal diamond (SCD) is the extreme wide bandgap material that is expected to revolutionize power electronics and radio-frequency electronics in the future. However, turning SCD into useful semiconductors requires overcoming doping challenges, as conventional substitutional doping techniques, such as thermal diffusion and ion implantation, are not easily applicable to SCD. Here we report a simple and easily accessible doping strategy demonstrating that electrically activated, substitutional doping in SCD without inducing graphitization transition or lattice damage can be readily realized with thermal diffusion at relatively low temperatures by using heavily doped Si nanomembranes as a unique dopant carrying medium. Atomistic simulations elucidate a vacancy exchange boron doping mechanism that occurs at the bonded interface between Si and diamond. We further demonstrate selectively doped high voltage diodes and half-wave rectifier circuits using such doped SCD. Our new doping strategy has established a reachable path toward using SCDs for future high voltage power conversion systems and for other novel diamond based electronic devices. The novel doping mechanism may find its critical use in other wide bandgap semiconductors.

  9. Temperature admittance spectroscopy of boron doped chemical vapor deposition diamond

    Energy Technology Data Exchange (ETDEWEB)

    Zubkov, V. I., E-mail: VZubkovspb@mail.ru; Kucherova, O. V.; Zubkova, A. V.; Ilyin, V. A.; Afanas' ev, A. V. [St. Petersburg State Electrotechnical University (LETI), Professor Popov Street 5, 197376 St. Petersburg (Russian Federation); Bogdanov, S. A.; Vikharev, A. L. [Institute of Applied Physics of the Russian Academy of Sciences, Ul' yanov Street 46, 603950 Nizhny Novgorod (Russian Federation); Butler, J. E. [St. Petersburg State Electrotechnical University (LETI), Professor Popov Street 5, 197376 St. Petersburg (Russian Federation); Institute of Applied Physics of the Russian Academy of Sciences, Ul' yanov Street 46, 603950 Nizhny Novgorod (Russian Federation); National Museum of Natural History (NMNH), P.O. Box 37012 Smithsonian Inst., Washington, D.C. 20013-7012 (United States)

    2015-10-14

    Precision admittance spectroscopy measurements over wide temperature and frequency ranges were carried out for chemical vapor deposition epitaxial diamond samples doped with various concentrations of boron. It was found that the experimentally detected boron activation energy in the samples decreased from 314 meV down to 101 meV with an increase of B/C ratio from 600 to 18000 ppm in the gas reactants. For the heavily doped samples, a transition from thermally activated valence band conduction to hopping within the impurity band (with apparent activation energy 20 meV) was detected at temperatures 120–150 K. Numerical simulation was used to estimate the impurity DOS broadening. Accurate determination of continuously altering activation energy, which takes place during the transformation of conduction mechanisms, was proposed by numerical differentiation of the Arrhenius plot. With increase of boron doping level the gradual decreasing of capture cross section from 3 × 10{sup −13} down to 2 × 10{sup −17} cm{sup 2} was noticed. Moreover, for the hopping conduction the capture cross section becomes 4 orders of magnitude less (∼2 × 10{sup −20} cm{sup 2}). At T > T{sub room} in doped samples the birth of the second conductance peak was observed. We attribute it to a defect, related to the boron doping of the material.

  10. ESR and Microwave Absorption in Boron Doped Diamond Single Crystals

    Science.gov (United States)

    Timms, Christopher

    2015-03-01

    Superconductivity has been reportedly found in boron-doped diamond. Most research to date has only studied superconductivity in polycrystalline and thin film boron-diamonds, as opposed to a single crystal. In fact, only one other group has examined a macro scale boron-doped diamond crystal. Our group has successfully grown large single crystals by using the High Temperature High Pressure method (HTHP) and observed a transition to metallic and superconducting states for high B concentrations. For the present, we are studying BDD crystal using Electron Spin Resonance. We conducted our ESR analysis over a range of temperatures (2K to 300K) and found several types of signals, proving the existence of charge carriers with spin 1/2 in BDD. Moreover, we have found that with increasing B concentrations, from n ~ 1018 cm-3 to n of over 1020 cm-3, the ESR signal changes from that of localized spins to the Dysonian shape of free carriers. The low magnetic field microwave absorption has also been studied in BDD samples at various B concentrations and the clear transition to superconducting state has been found below Tc that ranges from 2K to 4 K depending on concentration and quality of crystal. Sergey Polyakov, Victor Denisov, Vladimir Blank, Ray Baughman, Anvar Zakhidov.

  11. The boron doping of single crystal diamond for high power diode applications

    Science.gov (United States)

    Nicley, Shannon Singer

    Diamond has the potential to revolutionize the field of high power and high frequency electronic devices as a superlative electronic material. The realization of diamond electronics depends on the control of the growth process of both lightly and heavily boron doped diamond. This dissertation work is focused on furthering the state of the art of boron doped diamond (BDD) growth toward the realization of high power diamond Schottky barrier diodes (SBDs). The achievements of this work include the fabrication of a new dedicated reactor for lightly boron doped diamond deposition, the optimization of growth processes for both heavily and lightly boron doped single crystal diamond (SCD), and the proposal and realization of the corner architecture SBD. Boron doped SCD is grown in microwave plasma-assisted chemical vapor deposition (MPACVD) plasma disc bell-jar reactors, with feedgas mixtures including hydrogen, methane, carbon dioxide, and diborane. Characterization methods for the analysis of BDD are described, including Fourier-transformed infrared spectroscopy (FTIR), Secondary Ion Mass Spectroscopy (SIMS) and temperature-dependent four point probe conductivity for activation energy. The effect of adding carbon dioxide to the plasma feedgas for lightly boron doped diamond is investigated. The effect of diborane levels and other growth parameters on the incorporated boron levels are reported, and the doping efficiency is calculated over a range of boron concentrations. The presence of defects is shown to affect the doping uniformity. The substrate growth temperature dependence of the plasma gas-phase to solid-phase doping efficiency in heavily boron doped SCD deposition is investigated. The substrate temperature during growth is shown to have a significant effect on the grown sample defect morphology, and a temperature dependence of the doping efficiency is also shown. The effect of the growth rate on the doping efficiency is discussed, and the ratio of the boron

  12. Investigation of surface properties of boron doped diamond for developing neuron -machine interface

    OpenAIRE

    Vahidpour, Farnoosh

    2016-01-01

    Summary The main goal of this thesis is to study how diamond films advance the construction of the hybrid biological-solid state interfaces and to construct Micro-Electrode Arrays (MEAs) for neural recordings. First, a literature study was carried out to review diamond applications in biology for in vitro and in vivo and for Microelectrode arrays (MEAs). In order to develop diamond MEAs, nano crystalline diamond (NCD) and boron-doped nano crystalline diamond (BNCD) were synthetized on fuse...

  13. Properties of boron-doped epitaxial diamond layers grown on (110) oriented single crystal substrates

    OpenAIRE

    Mortet, Vincent; Pernot, J.; Jomard, F.; Soltani, A; Remes, Zdenek; Barjon, Julien; D'Haen, J; Haenen, Ken

    2015-01-01

    Boron doped diamond layers have been grown on (110) single crystal diamond substrates with B/C ratios up to 20 ppm in the gas phase. The surface of the diamond layers observed by scanning electron microscopy consists of (100) and (113) micro-facets. Fourier Transform Photocurrent Spectroscopy indicates substitutional boron incorporation. Electrical properties were measured using Hall effect from 150 to 1000 K. Secondary ion mass spectrometry analyses are consistent with the high incorporation...

  14. Electrochemical oxygen transfer reaction on synthetic boron-doped diamond thin film electrode

    OpenAIRE

    Marselli, Béatrice; Comninellis, Christos

    2005-01-01

    Synthetic boron-doped diamond thin film is a new promising anode material. Because of its properties (high anodic stability under drastic conditions and wide potential window), it is widely investigated for numerous possible electrochemical applications such as electrosynthesis, preparation of powerful oxidants and electroincineration. In the first part of this work, simple charge transfer was investigated at boron-doped diamond electrode through the study of an outer sphere system in the pot...

  15. Boron doped diamond electrodes in voltammetry: new designs and applications (an overview)

    OpenAIRE

    Zavázalová, Jaroslava; Barek, Jiří; Pecková, Karolina

    2014-01-01

    In this overview, the recent progress in the development and applications of bare boron doped diamond electrodes in voltammetry of organic compounds is summarized. Attention is paid to important issues reflected in last five years in electroanalytical studies, e.g. fouling and pretreatment of BDD surface, influence of boron concentration on performance of BDD-based sensors, and application of adsorptive stripping voltammetry.

  16. Boron Doped Nanocrystalline Diamond Films for Biosensing Applications

    Directory of Open Access Journals (Sweden)

    V. Petrák

    2011-01-01

    Full Text Available With the rise of antibiotic resistance of pathogenic bacteria there is an increased demand for monitoring the functionality of bacteria membranes, the disruption of which can be induced by peptide-lipid interactions. In this work we attempt to construct and disrupt supported lipid membranes (SLB on boron doped nanocrystalline diamond (B-NCD. Electrochemical Impedance Spectroscopy (EIS was used to study in situ changes related to lipid membrane formation and disruption by peptide-induced interactions. The observed impedance changes were minimal for oxidized B-NCD samples, but were still detectable in the low frequency part of the spectra. The sensitivity for the detection of membrane formation and disruption was significantly higher for hydrogenated B-NCD surfaces. Data modeling indicates large changes in the electrical charge when an electrical double layer is formed at the B-NCD/SLB interface, governed by ion absorption. By contrast, for oxidized B-NCD surfaces, these changes are negligible indicating little or no change in the surface band bending profile.

  17. Tribological properties of undoped and boron-doped nanocrystalline diamond films

    International Nuclear Information System (INIS)

    Undoped and boron-doped nanocrystalline (NCD) diamond films were deposited on mirror polished Ti-6Al-4V substrates in a Microwave Plasma Assisted Chemical Vapor Deposition system. Sliding wear tests were conducted in ambient air with a nanotribometer. A systematic study of the tribological properties for both undoped and boron-doped NCD films were carried out. It was found for diamond/diamond sliding, coefficient of friction decreases with increasing normal loads. It was also found that the wear rate of boron-doped NCD films is about 10 times higher than that of undoped films. A wear rate of ∼ 5.2 x 10-9 mm3/Nm was found for undoped NCD films. This value is comparable to the best known value of that of polished polycrystalline diamond films. Although no surface deformation, film delamination or micro-cracking were observed for undoped films, boron-doped NCD film undergoes a critical failure at a normal stress of 2.2 GPa, above which surface deformation is evident. Combined with high hardness and modulus, tunable conductivity and improved open air thermal stability, boron-doped nanocrystalline diamond film has tremendous potentials for applications such as Atomic Force Microscope probes, Micro-Electro-Mechanical System devices and biomedical sensors

  18. Thermal Diffusion Boron Doping of Single-Crystal Diamond

    OpenAIRE

    Seo, Jung-Hun; Wu, Henry; Mikael, Solomon; Mi, Hongyi; Blanchard, James P.; Venkataramanan, Giri; Zhou, Weidong; Gong, Sarah; Morgan, Dane; Ma, Zhenqiang

    2016-01-01

    With the best overall electronic and thermal properties, single crystal diamond (SCD) is the extreme wide bandgap material that is expected to revolutionize power electronics and radio-frequency electronics in the future. However, turning SCD into useful semiconductors requires overcoming doping challenges, as conventional substitutional doping techniques, such as thermal diffusion and ion implantation, are not easily applicable to SCD. Here we report a simple and easily accessible doping str...

  19. Cytotoxicity of Boron-Doped Nanocrystalline Diamond Films Prepared by Microwave Plasma Chemical Vapor Deposition

    Science.gov (United States)

    Liu, Dan; Gou, Li; Ran, Junguo; Zhu, Hong; Zhang, Xiang

    2015-07-01

    Boron-doped nanocrystalline diamond (NCD) exhibits extraordinary mechanical properties and chemical stability, making it highly suitable for biomedical applications. For implant materials, the impact of boron-doped NCD films on the character of cell growth (i.e., adhesion, proliferation) is very important. Boron-doped NCD films with resistivity of 10-2 Ω·cm were grown on Si substrates by the microwave plasma chemical vapor deposition (MPCVD) process with H2 bubbled B2O3. The crystal structure, diamond character, surface morphology, and surface roughness of the boron-doped NCD films were analyzed using different characterization methods, such as X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The contact potential difference and possible boron distribution within the film were studied with a scanning kelvin force microscope (SKFM). The cytotoxicity of films was studied by in vitro tests, including fluorescence microscopy, SEM and MTT assay. Results indicated that the surface roughness value of NCD films was 56.6 nm and boron was probably accumulated at the boundaries between diamond agglomerates. MG-63 cells adhered well and exhibited a significant growth on the surface of films, suggesting that the boron-doped NCD films were non-toxic to cells. supported by the Open Foundation of State Key Laboratory of Electronic Thin Films and Integrated Devices (University of Electronic Science and Technology of China) (No. KFJJ201313)

  20. Electronic structure of boron doped diamond: An x-ray spectroscopic study

    OpenAIRE

    Glans, P.-A.; Learmonth, T.; Smith, K. E.; Ferro, S.; Battisti, A.; Mattesini, Maurizio; Ahuja, R.; Guo, J. -H.

    2013-01-01

    The valence and conduction band electronic structure of boron-doped diamond has been measured using soft x-ray emission and absorption spectroscopy. The experimental results reveal p-type doping in the diamond film through the appearance of states in the band-gap. Structure distortion was observed around the doping center, while the long range order of the diamond structure remains. A chemically shifted C 1s level explains why one of the absorption features seems to appear below the valence b...

  1. Growth and electrical characterisation of {delta}-doped boron layers on (111) diamond surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Edgington, Robert; Jackman, Richard B. [London Centre for Nanotechnology, and Department of Electronic and Electrical Engineering, University College London, 17-19 Gordon Street, London, WC1H 0AH (United Kingdom); Sato, Syunsuke; Ishiyama, Yuichiro; Kawarada, Hiroshi [Department of Electronic and Photonic Systems, Waseda University, Okubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan); Morris, Richard [Advanced SIMS Projects, Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom)

    2012-02-01

    A plasma enhanced chemical vapor deposition protocol for the growth of {delta}-doping of boron in diamond is presented, using the (111) diamond plane as a substrate for diamond growth. AC Hall effect measurements have been performed on oxygen terminated {delta}-layers and desirable sheet carrier densities ({approx}10{sup 13} cm{sup -2}) for field-effect transistor application are reported with mobilities in excess of what would expected for equivalent but thicker heavily boron-doped diamond films. Temperature-dependent impedance spectroscopy and secondary ion mass spectroscopy measurements show that the grown layers have metallic-like electrical properties with high cut-off frequencies and low thermal impedance activation energies with estimated boron concentrations of approximately 10{sup 20} cm{sup -3}.

  2. Synthesis and characterization of p-type boron-doped IIb diamond large single crystals

    Institute of Scientific and Technical Information of China (English)

    Li Shang-Sheng; Ma Hong-An; Li Xiao-Lei; Su Tai-Chao; Huang Guo-Feng; Li Yong; Jia Xiao-Peng

    2011-01-01

    High-quality p-type boron-doped II0b diamond large single crystals are successfully synthesized by the temperature gradient method in a china-type cubic anvil high-pressure apparatus at about 5.5 GPa and 1600 K. The morphologies and surface textures of the synthetic diamond crystals with different boron additive quantities are characterized by using an optical microscope and a scanning electron microscope respectively. The impurities of nitrogen and boron in diamonds are detected by micro Fourier transform infrared technique. The electrical properties including resistivities, Hall coefficients, Hall mobilities and carrier densities of the synthesized samples are measured by a four-point probe and the Hall effect method. The results show that large p-type boron-doped diamond single crystals with few nitrogen impurities have been synthesized. With the increase of quantity of additive boron, some high-index crystal faces such as {113} gradually disappear, and some stripes and triangle pits occur on the crystal surface. This work is helpful for the further research and application of boron-doped semiconductor diamond.

  3. Synthesis of Boron-doped Diamond/Porous Ti Composite Materials——Effect of Carbon Concentration

    Institute of Scientific and Technical Information of China (English)

    MA Ming; CHANG Ming; LI Xiaowei

    2012-01-01

    Highly boron-doped diamond films were deposited on porous titanium substrates by hot filament chemical vapor deposition technique.The morphology variation of highly boron-doped diamond films grown on porous titanium substrates was investigated,and the effects of carbon concentration on nucleation density and diamond growth were also studied.The continuous change of surface morphology and structure of diamond film were characterized by scanning electron microscopy.The structures of diamond film and interlayer were analyzed by X-ray diffraction.The quality of boron-doped diamond film was confirmed by visible Raman spectroscopy.The experimental results reveal that surface morphology and quality of boron-doped diamond films are various due to the change of carbon concentration.The thickness of intermediate layer decreases with the carbon concentration increasing.

  4. Biocompatibility of nanostructured boron doped diamond for the attachment and proliferation of human neural stem cells

    Science.gov (United States)

    Taylor, Alice C.; Vagaska, Barbora; Edgington, Robert; Hébert, Clément; Ferretti, Patrizia; Bergonzo, Philippe; Jackman, Richard B.

    2015-12-01

    Objective. We quantitatively investigate the biocompatibility of chemical vapour deposited (CVD) nanocrystalline diamond (NCD) after the inclusion of boron, with and without nanostructuring. The nanostructuring method involves a novel approach of growing NCD over carbon nanotubes (CNTs) that act as a 3D scaffold. This nanostructuring of BNCD leads to a material with increased capacitance, and this along with wide electrochemical window makes BNCD an ideal material for neural interface applications, and thus it is essential that their biocompatibility is investigated. Approach. Biocompatibility was assessed by observing the interaction of human neural stem cells (hNSCs) with a variety of NCD substrates including un-doped ones, and NCD doped with boron, which are both planar, and nanostructured. hNSCs were chosen due to their sensitivity, and various methods including cell population and confluency were used to quantify biocompatibility. Main results. Boron inclusion into NCD film was shown to have no observable effect on hNSC attachment, proliferation and viability. Furthermore, the biocompatibility of nanostructured boron-doped NCD is increased upon nanostructuring, potentially due to the increased surface area. Significance. Diamond is an attractive material for supporting the attachment and development of cells as it can show exceptional biocompatibility. When boron is used as a dopant within diamond it becomes a p-type semiconductor, and at high concentrations the diamond becomes quasi-metallic, offering the prospect of a direct electrical device-cell interfacing system.

  5. Thermal shock resistance of thick boron-doped diamond under extreme heat loads

    NARCIS (Netherlands)

    De Temmerman, G.; Dodson, J.; Linke, J.; Lisgo, S.; Pintsuk, G.; Porro, S.; Scarsbrook, G.

    2011-01-01

    Thick free-standing boron-doped diamonds were prepared by microwave plasma assisted chemical vapour deposition. Samples with a final thickness close to 5 mm and with lateral dimensions 25 x 25 mm were produced. The thermal shock resistance of the material was tested by exposure in the JUDITH electro

  6. Voltammetric determination of wedelolactone, an anti-HIV herbal drug, at boron-doped diamond electrode

    Indian Academy of Sciences (India)

    Sachin Saxena; Ratnanjali Shrivastava; Soami P Satsangee

    2015-05-01

    Boron-doped diamond electrode has been utilized for the study of electrochemical behaviour of an anti-HIV herbal drug wedelolactone in Britton-Robinson buffer (pH-2.5) by square-wave and cyclic voltammetry techniques. The response characteristics of cyclic voltammetry and square wave voltammetry showed a remarkable increase in the anodic peak current and electrochemical impedance spectroscopy revealed a lowering in charge transfer resistance at the boron-doped diamond electrode as compared to the glassy carbon electrode that can be attributed to the higher sensitivity of boron-doped diamond sensor. Cyclic voltammetry at the boron-doped diamond surface revealed the oxidation of wedelolactone with two oxidation peaks (P1 and P2) with Ep1 = 0.4V and Ep2 =1.00 V with scan rate varying from 10 - 220 mV/s and exhibits diffusion-controlled process. Based on the electrochemical measurements, a probable oxidation mechanism has been deduced and the electrode dynamics parameters have been evaluated. The effect of concentration on the peak currents of wedelolactone was found to have a linear relationship within the concentration range of 50–700 ng/mL. The LOD and LOQ were found to be 43.87 and 132.93 ng/mL respectively. The applicability of the proposed method was further scrutinized by the successful determination of wedelolactone in real plant samples.

  7. Effect of Boron-Doped Diamond Interlayer on Cutting Performance of Diamond Coated Micro Drills for Graphite Machining

    Directory of Open Access Journals (Sweden)

    Zhiming Zhang

    2013-07-01

    Full Text Available Thin boron doped diamond (BDD film is deposited from trimethyl borate/acetone/hydrogen mixture on Co-cemented tungsten carbide (WC-Co micro drills by using the hot filament chemical vapor deposition (HFCVD technique. The boron peak on Raman spectrum confirms the boron incorporation in diamond film. This film is used as an interlayer for subsequent CVD of micro-crystalline diamond (MCD film. The Rockwell indentation test shows that boron doping could effectively improve the adhesive strength on substrate of as deposited thin diamond films. Dry drilling of graphite is chosen to check the multilayer (BDD + MCD film performance. For the sake of comparison, machining tests are also carried out under identical conditions using BDD and MCD coated micro drills with no interlayer. The wear mechanism of the tools has been identified and correlated with the criterion used to evaluate the tool life. The results show that the multilayer (BDD + MCD coated micro drill exhibits the longest tool life. Therefore, thin BDD interlayer is proved to be a new viable alternative and a suitable option for adherent diamond coatings on micro cutting tools.

  8. Metal-insulator transition and superconductivity in heavily boron-doped diamond and related materials

    Energy Technology Data Exchange (ETDEWEB)

    Achatz, Philipp

    2009-05-15

    During this PhD project, the metal-insulator transition and superconductivity of highly boron-doped single crystal diamond and related materials have been investigated. The critical boron concentration n{sub c} for the metal-insulator transition was found to be the same as for the normal-superconductor transition. All metallic samples have been found to be superconducting and we were able to link the occurence of superconductivity to the proximity to the metal-insulator transition. For this purpose, a scaling law approach based on low temperature transport was proposed. Furthermore, we tried to study the nature of the superconductivity in highly boron doped single crystal diamond. Raman spectroscopy measurements on the isotopically substituted series suggest that the feature occuring at low wavenumbers ({approx} 500 cm{sup -1}) is the A1g vibrational mode associated with boron dimers. Usual Hall effect measurements yielded a puzzling situation in metallic boron-doped diamond samples, leading to carrier concentrations up to a factor 10 higher than the boron concentration determined by secondary ion mass spectroscopy (SIMS). The low temperature transport follows the one expected for a granular metal or insulator, depending on the interplay of intergranular and intragranular (tunneling) conductance. The metal-insulator transition takes place at a critical conductance g{sub c}. The granularity also influences significantly the superconducting properties by introducing the superconducting gap {delta} in the grain and Josephson coupling J between superconducting grains. A peak in magnetoresistance is observed which can be explained by superconducting fluctuations and the granularity of the system. Additionally we studied the low temperature transport of boron-doped Si samples grown by gas immersion laser doping, some of which yielded a superconducting transition at very low temperatures. Furthermore, preliminary results on the LO-phonon-plasmon coupling are shown for the

  9. Metal-insulator transition and superconductivity in heavily boron-doped diamond and related materials

    International Nuclear Information System (INIS)

    During this PhD project, the metal-insulator transition and superconductivity of highly boron-doped single crystal diamond and related materials have been investigated. The critical boron concentration nc for the metal-insulator transition was found to be the same as for the normal-superconductor transition. All metallic samples have been found to be superconducting and we were able to link the occurence of superconductivity to the proximity to the metal-insulator transition. For this purpose, a scaling law approach based on low temperature transport was proposed. Furthermore, we tried to study the nature of the superconductivity in highly boron doped single crystal diamond. Raman spectroscopy measurements on the isotopically substituted series suggest that the feature occuring at low wavenumbers (∼ 500 cm-1) is the A1g vibrational mode associated with boron dimers. Usual Hall effect measurements yielded a puzzling situation in metallic boron-doped diamond samples, leading to carrier concentrations up to a factor 10 higher than the boron concentration determined by secondary ion mass spectroscopy (SIMS). The low temperature transport follows the one expected for a granular metal or insulator, depending on the interplay of intergranular and intragranular (tunneling) conductance. The metal-insulator transition takes place at a critical conductance gc. The granularity also influences significantly the superconducting properties by introducing the superconducting gap Δ in the grain and Josephson coupling J between superconducting grains. A peak in magnetoresistance is observed which can be explained by superconducting fluctuations and the granularity of the system. Additionally we studied the low temperature transport of boron-doped Si samples grown by gas immersion laser doping, some of which yielded a superconducting transition at very low temperatures. Furthermore, preliminary results on the LO-phonon-plasmon coupling are shown for the first time in aluminum-doped

  10. The effect of substrate temperature and growth rate on the doping efficiency of single crystal boron doped diamond

    Energy Technology Data Exchange (ETDEWEB)

    Demlow, SN; Rechenberg, R; Grotjohn, T

    2014-10-01

    The substrate growth temperature dependence of the plasma gas-phase to solid-phase doping efficiency in single crystal, boron doped diamond (BDD) deposition is investigated. Single crystal diamond (SCD) is grown by microwave plasma assisted chemical vapor deposition (MPACVD) on high pressure, high temperature (HPHT) type Ib substrates. Samples are grown at substrate temperatures of 850-950 degrees C for each of five doping concentration levels, to determine the effect of the growth temperature on the doping efficiency and defect morphology. The substrate temperature during growth is shown to have a significant effect on the grown sample defect morphology, and a temperature dependence of the doping efficiency is also shown. The effect of the growth rate on the doping efficiency is discussed, and the ratio of the boron concentration in the gas phase to the flux of carbon incorporated into the solid diamond phase is shown to be a more predictive measure of the resulting boron concentration than the gas phase boron to carbon ratio that is more commonly reported. (C) 2014 Elsevier B.V. All rights reserved.

  11. Electroanalysis of tetracycline using nickel-implanted boron-doped diamond thin film electrode applied to flow injection system.

    Science.gov (United States)

    Treetepvijit, Surudee; Chuanuwatanakul, Suchada; Einaga, Yasuaki; Sato, Rika; Chailapakult, Orawon

    2005-05-01

    The electrochemical analysis of tetracycline was investigated using nickel-implanted boron-doped diamond thin film electrode by cyclic voltammetry and amperometry with a flow injection system. Cyclic voltammetry was used to study the electrochemical oxidation of tetracycline. Comparison experiments were carried out using as-deposited boron-doped diamond thin film electrode (BDD). Nickel-implanted boron-doped diamond thin film electrode (Ni-DIA) provided well-resolved oxidation irreversible cyclic voltammograms. The current signals were higher than those obtained using the as-deposited BDD electrode. Results using nickel-implanted boron-doped diamond thin film electrode in flow injection system coupled with amperometric detection are presented. The optimum potential for tetracycline was 1.55 V versus Ag/AgCl. The linear range of 1.0 to 100 microM and the detection limit of 10 nM were obtained. In addition, the application for drug formulation was also investigated.

  12. Soft X-ray angle-resolved photoemission spectroscopy of heavily boron-doped superconducting diamond films

    Directory of Open Access Journals (Sweden)

    T. Yokoya, T. Nakamura, T. Matushita, T. Muro, H. Okazaki, M. Arita, K. Shimada, H. Namatame, M. Taniguchi, Y. Takano, M. Nagao, T. Takenouchi, H. Kawarada and T. Oguchi

    2006-01-01

    Full Text Available We have performed soft X-ray angle-resolved photoemission spectroscopy (SXARPES of microwave plasma-assisted chemical vapor deposition diamond films with different B concentrations in order to study the origin of the metallic behavior of superconducting diamond. SXARPES results clearly show valence band dispersions with a bandwidth of ~23 eV and with a top of the valence band at gamma point in the Brillouin zone, which are consistent with the calculated valence band dispersions of pure diamond. Boron concentration-dependent band dispersions near the Fermi level (EF exhibit a systematic shift of EF, indicating depopulation of electrons due to hole doping. These SXARPES results indicate that diamond bands retain for heavy boron doping and holes in the diamond band are responsible for the metallic states leading to superconductivity at low temperature. A high-resolution photoemission spectroscopy spectrum near EF of a heavily boron-doped diamond superconductor is also presented.

  13. Multiple delta doping of single crystal cubic boron nitride films heteroepitaxially grown on (001)diamonds

    Energy Technology Data Exchange (ETDEWEB)

    Yin, H., E-mail: hyin@jlu.edu.cn [State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China); Ziemann, P. [Institute of Solid State Physics, Ulm University, D-89069 Ulm (Germany)

    2014-06-23

    Phase pure cubic boron nitride (c-BN) films have been epitaxially grown on (001) diamond substrates at 900 °C. The n-type doping of c-BN epitaxial films relies on the sequential growth of nominally undoped (p-) and Si doped (n-) layers with well-controlled thickness (down to several nanometer range) in the concept of multiple delta doping. The existence of nominally undoped c-BN overgrowth separates the Si doped layers, preventing Si dopant segregation that was observed for continuously doped epitaxial c-BN films. This strategy allows doping of c-BN films can be scaled up to multiple numbers of doped layers through atomic level control of the interface in the future electronic devices. Enhanced electronic transport properties with higher hall mobility (10{sup 2} cm{sup 2}/V s) have been demonstrated at room temperature as compared to the normally continuously Si doped c-BN films.

  14. Influence of structural disorder and Coulomb interactions in the superconductor-insulator transition applied to boron doped diamond

    OpenAIRE

    McIntosh, R.; Mohanta, N.; Taraphder, A.; Bhattacharyya, S.

    2015-01-01

    The influence of disorder, both structural (non-diagonal) and on-site (diagonal), is studied through the inhomogeneous Bogoliubov-de Gennes (BdG) theory in narrow-band disordered superconductors with a view towards understanding superconductivity in boron doped diamond (BDD) and boron- doped nanocrystalline diamond (BNCD) films. We employ the attractive Hubbard model within the mean field approximation, including the Coulomb interaction between holes in the narrow acceptor band. We study subs...

  15. Critical boron-doping levels for generation of dislocations in synthetic diamond

    Energy Technology Data Exchange (ETDEWEB)

    Alegre, M. P., E-mail: maripaz.alegre@uca.es; Araújo, D.; Pinero, J. C.; Lloret, F.; Villar, M. P. [Departamento de Ciencias de los Materiales e Ingeniería Metalúrgica y Química, Universidad de Cádiz, 11510 Puerto Real, Cádiz (Spain); Fiori, A.; Achatz, P.; Chicot, G.; Bustarret, E. [Université Grenoble Alpes, Institut NEEL, 25 av. des Martyrs, 38042 Grenoble (France); Jomard, F. [GEMaC, CNRS and Université de Versailles St Quentin, 45 Avenue des États-Unis, 78035 Versailles (France)

    2014-10-27

    Defects induced by boron doping in diamond layers were studied by transmission electron microscopy. The existence of a critical boron doping level above which defects are generated is reported. This level is found to be dependent on the CH{sub 4}/H{sub 2} molar ratios and on growth directions. The critical boron concentration lied in the 6.5–17.0 × 10{sup 20}at/cm{sup 3} range in the 〈111〉 direction and at 3.2 × 10{sup 21 }at/cm{sup 3} for the 〈001〉 one. Strain related effects induced by the doping are shown not to be responsible. From the location of dislocations and their Burger vectors, a model is proposed, together with their generation mechanism.

  16. Reactivity of electrogenerated free hydroxyl radicals and activation of dioxygen on boron-doped diamond electrodes

    OpenAIRE

    Kapalka, Agnieszka

    2008-01-01

    Synthetic boron-doped diamond (BDD) thin film is an electrode material with high chemical and dimensional stability, low background current and a very wide potential window of water stability. Upon anodic polarization, BDD generates hydroxyl radicals that mediate the oxidation processes in the vicinity of the electrode surface. These hydroxyl radials are assumed to be free, i.e., not adsorbed on the electrode surface. Hydroxyl radicals are formed on BDD during water discharge, which is the ra...

  17. Boron-doped nanocrystalline diamond electrodes for neural interfaces: In vivo biocompatibility evaluation

    OpenAIRE

    María eAlcaide; Andrew eTaylor; Morten eFjorback; Vladimir eZachar; Cristian Pablo Pennisi

    2016-01-01

    Boron-doped nanocrystalline diamond (BDD) electrodes have recently attracted attention as materials for neural electrodes due to their superior physical and electrochemical properties, however their biocompatibility remains largely unexplored. In this work, we aim to investigate the in vivo biocompatibility of BDD electrodes in relation to conventional titanium nitride (TiN) electrodes using a rat subcutaneous implantation model. High quality BDD films were synthesized on electrodes intended ...

  18. Boron-Doped Nanocrystalline Diamond Electrodes for Neural Interfaces: In vivo Biocompatibility Evaluation

    OpenAIRE

    Alcaide, María; Taylor, Andrew; Fjorback, Morten; Zachar, Vladimir; Pennisi, Cristian P.

    2016-01-01

    Boron-doped nanocrystalline diamond (BDD) electrodes have recently attracted attention as materials for neural electrodes due to their superior physical and electrochemical properties, however their biocompatibility remains largely unexplored. In this work, we aim to investigate the in vivo biocompatibility of BDD electrodes in relation to conventional titanium nitride (TiN) electrodes using a rat subcutaneous implantation model. High quality BDD films were synthesized on electrodes intended ...

  19. Investigations of electrochemical oxygen transfer reaction on boron-doped diamond electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Kapalka, Agnieszka; Foti, Gyoergy [Institute of Chemical Sciences and Engineering, Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Comninellis, Christos [Institute of Chemical Sciences and Engineering, Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)], E-mail: christos.comninellis@epfl.ch

    2007-12-31

    In this paper, the electrochemical oxygen transfer reaction (EOTR) is studied on boron-doped diamond electrodes using simple C{sub 1} organic compounds (methanol and formic acid). The kinetics of both oxygen evolution (side reaction) and organics oxidation (main reaction) has been investigated using boron-doped diamond microelectrodes-array (BDD MEA). Oxygen evolution, in the high-potential region, takes place with a Tafel slope of 120 mV dec{sup -1} and zero reaction order with respect to H{sup +}. In the presence of organics, a shift of the polarization curves to lower potentials is observed while the Tafel slopes remain close to 120 mV dec{sup -1}. A simplified model of C{sub 1} organics oxidation is proposed. Both water discharge and organics oxidation are assumed to be fast reactions. The slowest step of the studied EOTR is the anodic discharge of hydroxyl radicals to oxygen. Further in this work, electrolysis of formic acid on boron-doped diamond macroelectrode is presented. In order to achieve 100% current efficiency, electrolysis was carried out under programmed current, in which the current density was adjusted to the limiting value.

  20. Boron doped diamond electrode for the wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Quiroz Alfaro, Marco Antonio [Universidad de las Americas-Puebla, Santa Catarina Martir (Mexico). Escuela de Ciencias. Dept. de Quimica y Biologia; Ferro, Sergio; Martinez-Huitle, Carlos Alberto [University of Ferrara (Italy). Dept. of Chemistry; Vong, Yunny Meas [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica S.C., Quertaro (Mexico). Parque Tecnologico Queretaro Sanfandila

    2006-03-15

    Electrochemical studies of diamond were started more than fifteen years ago with the first paper on diamond electrochemistry published by Pleskov. After that, work started in Japan, United States of America, France, Switzerland and other countries. Over the last few years, the number of publications has increased considerably. Diamond films have been the subject of applications and fundamental research in electrochemistry, opening up a new branch known as the electrochemistry of diamond electrodes. Here, we first present a brief history and the process of diamond film synthesis. The principal objective of this work is to summarize the most important results in the electrochemical oxidation using diamond electrodes. (author)

  1. Comparison of the chemical composition of boron-doped diamond surfaces upon different oxidation processes

    International Nuclear Information System (INIS)

    In spite of the high stability of polycrystalline diamond, oxidation of the hydrogenated surface is relatively easy to perform. This results in the introduction of ether (C-O-C), carbonyl (C=O) and hydroxyl (C-OH) groups on the surface. For further surface functionalization, it is important to quantify the presence of each group on the diamond surface when different oxidation processes are used. In this paper, we investigate the composition of oxidized boron-doped diamond surfaces using X-ray photoelectron spectroscopy (XPS) when electrochemical, photochemical or oxygen plasma methods were employed to introduce oxygen functionalities on as-deposited diamond interfaces. Cyclic voltammetry and C-V measurements were additionally performed to identify more clearly the formation of C-OH, C-O-C and/or C=O functions.

  2. Formation of Boron-Carbon Nanosheets and Bilayers in Boron-Doped Diamond: Origin of Metallicity and Superconductivity.

    Science.gov (United States)

    Polyakov, S N; Denisov, V N; Mavrin, B N; Kirichenko, A N; Kuznetsov, M S; Martyushov, S Yu; Terentiev, S A; Blank, V D

    2016-12-01

    The insufficient data on a structure of the boron-doped diamond (BDD) has frustrated efforts to fully understand the fascinating electronic properties of this material and how they evolve with doping. We have employed X-ray diffraction and Raman scattering for detailed study of the large-sized BDD single crystals. We demonstrate a formation of boron-carbon (B-C) nanosheets and bilayers in BDD with increasing boron concentration. An incorporation of two boron atoms in the diamond unit cell plays a key role for the B-C nanosheets and bilayer formation. Evidence for these B-C bilayers which are parallel to {111} planes is provided by the observation of high-order, super-lattice reflections in X-ray diffraction and Laue patterns. B-C nanosheets and bilayers minimize the strain energy and affect the electronic structure of BDD. A new shallow acceptor level associated with B-C nanosheets at ~37 meV and the spin-orbit splitting of the valence band of ~6 meV are observed in electronic Raman scattering. We identified that the superconducting transitions occur in the (111) BDD surfaces only. We believe that the origin of Mott and superconducting transitions is associated with the two-dimensional (2D) misfit layer structure of BDD. A model for the BDD crystal structure, based on X-ray and Raman data, is proposed and confirmed by density functional theoretical calculation. PMID:26754937

  3. Friction and Wear Performance of Boron Doped, Undoped Microcrystalline and Fine Grained Composite Diamond Films

    Institute of Scientific and Technical Information of China (English)

    WANG Xinchang; WANG Liang; SHEN Bin; SUN Fanghong

    2015-01-01

    Chemical vapor deposition (CVD) diamond films have attracted more attentions due to their excellent mechanical properties. Whereas as-fabricated traditional diamond films in the previous studies don’t have enough adhesion or surface smoothness, which seriously impact their friction and wear performance, and thus limit their applications under extremely harsh conditions. A boron doped, undoped microcrystalline and fine grained composite diamond (BD-UM-FGCD) film is fabricated by a three-step method adopting hot filament CVD (HFCVD) method in the present study, presenting outstanding comprehensive performance, including the good adhesion between the substrate and the underlying boron doped diamond (BDD) layer, the extremely high hardness of the middle undoped microcrystalline diamond (UMCD) layer, as well as the low surface roughness and favorable polished convenience of the surface fine grained diamond (FGD) layer. The friction and wear behavior of this composite film sliding against low-carbon steel and silicon nitride balls are studied on a ball-on-plate rotational friction tester. Besides, its wear rate is further evaluated under a severer condition using an inner-hole polishing apparatus, with low-carbon steel wire as the counterpart. The test results show that the BD-UM-FGCD film performs very small friction coefficient and great friction behavior owing to its high surface smoothness, and meanwhile it also has excellent wear resistance because of the relatively high hardness of the surface FGD film and the extremely high hardness of the middle UMCD film. Moreover, under the industrial conditions for producing low-carbon steel wires, this composite film can sufficiently prolong the working lifetime of the drawing dies and improve their application effects. This research develops a novel composite diamond films owning great comprehensive properties, which have great potentials as protecting coatings on working surfaces of the wear-resistant and anti

  4. Influence of growth pressure on the electrical properties of boron-doped polycrystalline diamond films

    International Nuclear Information System (INIS)

    Heavily boron-doped diamond films are synthesized by the hot-filament chemical vapor deposition method under the gas mixtures of H2, CH4 and trimethyl borate. The measurement results of scanning electron microscopy, Raman spectroscopy, X-ray diffractometer and electrical properties showed the morphologies, microstructures, carrier concentration and superconducting transition temperature for as-grown diamond films were dependent on the change of growth pressure, and specially its carrier concentrations could be adjusted from 1019 to 1021 cm-3 by increasing growth pressures from 2.5 to 5 kPa. And further, the effects of growth pressure on the film microstructural property and the doping level dependence of the superconducting transition temperature were discussed.

  5. Raman Microscopic Analysis of Internal Stress in Boron-Doped Diamond

    Directory of Open Access Journals (Sweden)

    Kevin E. Bennet

    2015-05-01

    Full Text Available Analysis of the induced stress on undoped and boron-doped diamond (BDD thin films by confocal Raman microscopy is performed in this study to investigate its correlation with sample chemical composition and the substrate used during fabrication. Knowledge of this nature is very important to the issue of long-term stability of BDD coated neurosurgical electrodes that will be used in fast-scan cyclic voltammetry, as potential occurrence of film delaminations and dislocations during their surgical implantation can have unwanted consequences for the reliability of BDD-based biosensing electrodes. To achieve a more uniform deposition of the films on cylindrically-shaped tungsten rods, substrate rotation was employed in a custom-built chemical vapor deposition reactor. In addition to visibly preferential boron incorporation into the diamond lattice and columnar growth, the results also reveal a direct correlation between regions of pure diamond and enhanced stress. Definite stress release throughout entire film thicknesses was found in the current Raman mapping images for higher amounts of boron addition. There is also a possible contribution to the high values of compressive stress from sp2 type carbon impurities, besides that of the expected lattice mismatch between film and substrate.

  6. Freestanding CVD boron doped diamond single crystals: A substrate for vertical power electronic devices?

    Energy Technology Data Exchange (ETDEWEB)

    Achard, J.; Issaoui, R.; Tallaire, A.; Silva, F.; Gicquel, A. [Universite Paris 13, Sorbonne Paris Cite, Laboratoire des Sciences des Procedes et des Materiaux, CNRS (UPR 3407), 93430 Villetaneuse (France); Barjon, J.; Jomard, F. [GEMaC, CNRS-Universite de Versailles St-Quentin, 45 av. des Etats-Unis, 78035 Versailles Cedex (France)

    2012-09-15

    The development of 'all-diamond' devices for power electronics is attracting more and more interest as judged by the recent increase in the number of publications on the subject. Nevertheless most devices reported in the literature used coplanar or pseudo-vertical geometries which, although promising in term of breakdown voltage, have still a relatively high on-state resistance. This could be related to current crowding due the low cross-section p{sup +} layer. Vertical configuration, which requires thick heavily doped substrates, is a possible alternative usually used in conventional semiconductors. In this study, chemical vapour deposition (CVD) diamond growth conditions allowing heavy boron doping over an important thickness are discussed. It was found that there is an optimal range of microwave power density (MWPD) for which reasonable doping efficiencies and growth rates can be obtained leading to hundreds of micrometers thick crystals with a doping level higher than 10{sup 20} cm{sup -3}. The crystal morphology was predicted thanks to a 3D geometrical model and a small addition of oxygen to the gas phase was efficient to avoid the appearance of undesirable crystals faces and keep the crystal integrity. Freestanding boron-doped diamond single crystals were eventually grown and characterized by secondary ion mass spectrometry (SIMS), Fourier transformed InfraRed (FTIR) spectroscopy, Raman spectroscopy, high resolution X-ray diffraction (HRXRD) and four-point probe measurements. The high quality of the synthetic crystals was confirmed exhibiting electrical resistivities as low as 0.26 {Omega} cm illustrating that this material is suitable for the development of vertical power electronic devices. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Functionalization of Boron-Doped Nanocrystalline Diamond with N3 Dye Molecules

    OpenAIRE

    Yeap, Weng Siang; X. Liu; Bevk, David; Pasquarelli, A.; Lutsen, Laurence; Fahlman, M.; Maes, Wouter; Haenen, Ken

    2014-01-01

    N3 dye molecules [cis-bis(isothiocyanato)bis(2,2'-bipyridyl-4,4'-dicarboxylato)ruthenium(II)] are covalently attached to boron-doped nanocrystalline diamond (B:NCD) thin films through a combination of coupling chemistries, i.e., diazonium, Suzuki, and EDC-NHS. X-ray and ultraviolet photoelectron spectroscopy and near-edge X-ray absorption fine structure spectroscopy are used to verify the covalent bonding of the dye on the B:NCD surface (compared to a hydrogen-terminated reference). The spect...

  8. Localized electropolymerization on oxidized boron-doped diamond electrodes modified with pyrrolyl units.

    Science.gov (United States)

    Actis, Paolo; Manesse, Mael; Nunes-Kirchner, Carolina; Wittstock, Gunther; Coffinier, Yannick; Boukherroub, Rabah; Szunerits, Sabine

    2006-11-14

    This paper describes the functionalization of oxidized boron-doped diamond (BDD) electrodes with N-(3-trimethoxysilylpropyl)pyrrole (TMPP) and the influence of this layer on the electrochemical transfer kinetics as well as on the possibility of forming strongly adhesive polypyrrole films on the BDD interface through electropolymerization. Furthermore, localized polymer formation was achieved on the TMPP-modified BDD interface using the direct mode of a scanning electrochemical microscope (SECM) as well as an electrochemical scanning near-field optical microscope (E-SNOM). Depending on the method used polypyrrole dots with diameters in the range of 1-250 microm are electrogenerated. PMID:17066183

  9. Simultaneous Chronoamperometric Sensing of Ascorbic Acid and Acetaminophen at a Boron-Doped Diamond Electrode

    OpenAIRE

    Ciprian Radovan; Codruţa Cofan

    2008-01-01

    Cyclic voltammetry (CV) and chronoamperometry (CA) have been used to sense and determine simultaneously L-ascorbic acid (AA) and acetaminophen (AC) at a boron-doped diamond electrode (BDDE) in a Britton-Robinson buffer solution. The calibration plots of anodic current peak versus concentration obtained from CV and CA data for both investigated compounds in single and di-component solutions over the concentration range 0.01 mM – 0.1 mM proved to be linear, with very good correlation param...

  10. A detailed analysis of the Raman spectra in superconducting boron doped nanocrystalline diamond

    Energy Technology Data Exchange (ETDEWEB)

    Szirmai, Peter [Faculty of Physics, University of Vienna, Strudlhofgasse 4, 1090 Vienna (Austria); Department of Physics, Budapest University of Technology and Economics, PO Box 91, 1521 Budapest (Hungary); Pichler, Thomas [Faculty of Physics, University of Vienna, Strudlhofgasse 4, 1090 Vienna (Austria); Williams, Oliver A. [School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom); Mandal, Soumen; Baeuerle, Christopher [Institut Neel - CNRS and Universite Joseph Fourier, 38042 Grenoble (France); Simon, Ferenc [Department of Physics, Budapest University of Technology and Economics, PO Box 91, 1521 Budapest (Hungary)

    2012-12-15

    The light scattering properties of superconducting (T{sub c} {approx} 3.8 K) heavily boron doped nanocrystalline diamond has been investigated by Raman spectroscopy using visible excitations. Fano type interference of the zone-center phonon line and the electronic continuum was identified. Lineshape analysis reveals Fano lineshapes with a significant asymmetry (q {approx} -2). An anomalous wavelength dependence and small value of the Raman scattering amplitude is observed in agreement with previous studies. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. A detailed analysis of the Raman spectra in superconducting boron doped nanocrystalline diamond

    International Nuclear Information System (INIS)

    The light scattering properties of superconducting (Tc ∼ 3.8 K) heavily boron doped nanocrystalline diamond has been investigated by Raman spectroscopy using visible excitations. Fano type interference of the zone-center phonon line and the electronic continuum was identified. Lineshape analysis reveals Fano lineshapes with a significant asymmetry (q ∼ -2). An anomalous wavelength dependence and small value of the Raman scattering amplitude is observed in agreement with previous studies. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Domestic and Industrial Water Disinfection Using Boron-Doped Diamond Electrodes

    Science.gov (United States)

    Rychen, Philippe; Provent, Christophe; Pupunat, Laurent; Hermant, Nicolas

    This chapter first describes main properties and manufacturing process (production using HF-CVD, quality-control measurements, etc.) of diamond electrodes and more specifically boron-doped diamond (BDD) electrodes. Their exceptional properties make such electrodes particularly suited for many disinfection applications as thanks to their wide working potential window and their high anodic potential, they allow generating a mixture of powerful oxidizing species mainly based on active oxygen and peroxides. Such mixture of disinfecting agents is far more efficient than conventional chemical or physical known techniques. Their efficiency was tested against numerous microorganisms and then proved to be greater than conventional methods. All bacteria and viruses tested up to date were inactivated 3-5 times faster with a treatment based on with BDD electrodes and the DiaCellⓇ technology than with other techniques. Several applications, either industrial or private (wellness and home use), are discussed with a focus on the dedicated products and the main technology advantages.

  13. Effects of the surface-adsorption of boron-doped diamond electrode on its electrochemical behavior

    Institute of Scientific and Technical Information of China (English)

    LIU Fengbin; LI Xuemin; WANG Jiadao; LIU Bing; CHEN Darong

    2006-01-01

    To elucidate the effects of the hydro- genation and oxygenation of the boron-doped diamond (BDD) electrode on its electrochemical behaviors, the surface morphologies and phases of the two surface-adsorption BDD films have been investigated and the cyclic voltammograms and AC impedance spectra have been measured at these two BDD electrodes. The results indicate that compared with the hydrogen-adsorption BDD film, oxygen-adsor- ption BDD film is less conductive, and has a larger surface roughness and a lower sp3/sp2 ratio. The oxygenated BDD film electrode possesses a wider electrochemical window, larger diamond film resistance and capacitance and a larger polarization resistance than hydrogenated BDD electrode. In addition, the effect mechanism of the surface-adsorption of BDD electrode on its electrochemical behaviors has been discussed.

  14. Benzene Oxidation on Boron-Doped Diamond Electrode: Electrochemical-Impedance Study of Adsorption Effects

    Directory of Open Access Journals (Sweden)

    Yuri Pleskov

    2012-01-01

    Full Text Available Benzene oxidation at a boron-doped diamond anode in 0.5 M K2SO4 aqueous solution is studied by cyclic voltammetry and electrochemical impedance spectroscopy. It is shown by measurements of differential capacitance and anodic current that in the ideal-polarizability potential region benzene either is not adsorbed at the diamond electrode or the benzene adsorption does not affect its capacitance. At more positive potentials, the adsorption of some intermediate of the benzene oxidation occurs at the electrode. The intermediate partially blocks the electrode surface and lowers the anodic current. The very fact of the electrode surface blocking is reflected in the complex-plane presentation of the impedance-potential plots.

  15. Electrochemical Incineration of Phenolic Compounds from the Hydrocarbon Industry Using Boron-Doped Diamond Electrodes

    Directory of Open Access Journals (Sweden)

    Alejandro Medel

    2012-01-01

    Full Text Available Electrochemical incineration using boron-doped diamond electrodes was applied to samples obtained from a refinery and compared to the photo-electro-Fenton process in order to selectively eliminate the phenol and phenolic compounds from a complex matrix. Due to the complex chemical composition of the sample, a pretreatment to the sample in order to isolate the phenolic compounds was applied. The effects of the pretreatment and of pH on the degradation of the phenolic compounds were evaluated. The results indicate that the use of a boron-doped diamond electrode in an electrochemical incineration process mineralizes 99.5% of the phenolic sample content. Working in acidic medium (pH = 1, and applying 2 A at 298 K under constant stirring for 2 hours, also results in the incineration of the reaction intermediates reflected by 97% removal of TOC. In contrast, the photo-electro-Fenton process results in 99.9% oxidation of phenolic compounds with only a 25.69% removal of TOC.

  16. Effect of nitrogen on deposition and field emission properties of boron-doped micro-and nano-crystalline diamond films

    Institute of Scientific and Technical Information of China (English)

    L.A. Li; S.H. Cheng; H.D. Li; Q. Yu; J.W. Liu; X.Y. Lv

    2010-01-01

    In this paper, we report the effect of nitrogen on the deposition and properties of boron doped diamond films synthesized by hot filament chemical vapor deposition. The diamond films consisting of micro-grains (nano-grains) were realized with low (high) boron source flow rate during the growth processes. The transition of micro-grains to nano-grains is speculated to be strongly (weekly) related with the boron (nitrogen) flow rate. The grain size and Raman spectral feature vary insignificantly as a function of the nitrogen introduction at a certain boron flow rate. The variation of electron field emission characteristics dependent on nitrogen is different between microcrystalline and nanocrystalline boron doped diamond samples, which are related to the combined phase composition, boron doping level and texture structure. There is an optimum nitrogen proportion to improve the field emission properties of the boron-doped films.

  17. DC current and AC impedance measurements on boron-doped single crystalline diamond films

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Haitao; Gaudin, O.; Jackman, R.B. [Department of Electronic and Electrical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom); Muret, P.; Gheeraert, E. [Laboratoire d' Etudes des Proprietes Electroniques des Solides, BP166, 38042 Grenoble Cedex 9 (France)

    2003-09-01

    In this paper, we report the first measurement of impedance on boron-doped single crystalline diamond films from 0.1 Hz to 10 MHz with the temperature ranging from -100 C up to 300 C. The Cole-Cole (Z' via Z{sup ''}) plots are well fitted to a RC parallel circuit model and the equivalent Resistance and Capacitance for the diamond films have been estimated using the Zview curve fitting. The results show only one single semicircle response at each temperature measured. It was found that the resistance decreases from 70 G{omega} at -100 C to 5 k{omega} at 300 C. The linear curve fitting from -100 C to 150 C shows the sample has an activation energy of 0.37 eV, which is consistent with the theoretical value published of this kind of material. The equivalent capacitance is maintained at the level of pF up to 300 C suggesting that no grain boundaries are being involved, as expected from a single crystal diamond. The activation energy from the dc current-temperature curves is 0.36 eV, which is consistent with the value from ac impedance. The potential of this under-used technique for diamond film analysis will be discussed. (copyright 2003 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Increased charge storage capacity of titanium nitride electrodes by deposition of boron-doped nanocrystalline diamond films

    DEFF Research Database (Denmark)

    Meijs, Suzan; McDonald, Matthew; Sørensen, Søren;

    2015-01-01

    The aim of this study was to investigate the feasibility of depositing a thin layer of boron-doped nanocrystalline diamond (B-NCD) on titanium nitride (TiN) coated electrodes and the effect this has on charge injection properties. The charge storage capacity increased by applying the B-NCD film...

  19. ortho-Selective phenol-coupling reaction by anodic treatment on boron-doped diamond electrode using fluorinated alcohols.

    Science.gov (United States)

    Kirste, Axel; Nieger, Martin; Malkowsky, Itamar M; Stecker, Florian; Fischer, Andreas; Waldvogel, Siegfried R

    2009-01-01

    Enlarged scope by fluorinated mediators: Oxyl radicals are easily formed on boron-doped diamond (BDD) electrodes and can be exploited for the ortho-selective coupling to the corresponding biphenols (see scheme). At partial conversion, a clean transformation is achieved that can be applied to electron-rich as well as fluorinated phenols.

  20. Boron concentration profiling by high angle annular dark field-scanning transmission electron microscopy in homoepitaxial δ-doped diamond layers

    Energy Technology Data Exchange (ETDEWEB)

    Araújo, D.; Alegre, M. P.; Piñero, J. C. [Dpto Ciencia de los Materiales, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real (Cádiz) (Spain); Fiori, A.; Bustarret, E. [Institut Néel, CNRS-Université Joseph Fourier, 25 av. des Martyrs, 38042 Grenoble (France); Jomard, F. [Groupe d' Etude de la Matière Condensée (GEMaC), UMR 8635 du CNRS, UVSQ, 45 av. des Etats-Unis, 78035 Versailles Cedex (France)

    2013-07-22

    To develop further diamond related devices, the concentration and spatial location of dopants should be controlled down to the nanometer scale. Scanning transmission electron microscopy using the high angle annular dark field mode is shown to be sensitive to boron doping in diamond epilayers. An analytical procedure is described, whereby local boron concentrations above 10{sup 20} cm{sup −3} were quantitatively derived down to nanometer resolution from the signal dependence on thickness and boron content. Experimental boron local doping profiles measured on diamond p{sup −}/p{sup ++}/p{sup −} multilayers are compared to macroscopic profiles obtained by secondary ion mass spectrometry, avoiding reported artefacts.

  1. Electronic and physico-chemical properties of nanometric boron delta-doped diamond structures

    Energy Technology Data Exchange (ETDEWEB)

    Chicot, G., E-mail: gauthier.chicot@neel.cnrs.fr; Fiori, A.; Tran Thi, T. N.; Bousquet, J.; Delahaye, J.; Grenet, T.; Eon, D.; Omnès, F.; Bustarret, E. [Université Grenoble Alpes, Institut NEEL, 38042 Grenoble (France); CNRS, Institut NEEL, 38042 Grenoble (France); Volpe, P. N.; Tranchant, N.; Mer-Calfati, C.; Arnault, J. C. [CEA, LIST, Diamond Sensors Laboratory, 91191 Gif-sur-Yvette (France); Gerbedoen, J. C.; Soltani, A.; De Jaeger, J. C. [IEMN, UMR-CNRS 8520, Avenue Poincaré, Université de Lille 1, 59652 Villeneuve d' Ascq (France); Alegre, M. P.; Piñero, J. C.; Araújo, D. [Dpto Ciencia de los Materiales, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real (Cádiz) (Spain); Jomard, F. [Groupe d' Étude de la Matière Condensée (GEMaC), UMR 8635 du CNRS, UVSQ, 45 Avenue des États-Unis, 78035 Versailles Cedex (France); and others

    2014-08-28

    Heavily boron doped diamond epilayers with thicknesses ranging from 40 to less than 2 nm and buried between nominally undoped thicker layers have been grown in two different reactors. Two types of [100]-oriented single crystal diamond substrates were used after being characterized by X-ray white beam topography. The chemical composition and thickness of these so-called delta-doped structures have been studied by secondary ion mass spectrometry, transmission electron microscopy, and spectroscopic ellipsometry. Temperature-dependent Hall effect and four probe resistivity measurements have been performed on mesa-patterned Hall bars. The temperature dependence of the hole sheet carrier density and mobility has been investigated over a broad temperature range (6 K < T < 450 K). Depending on the sample, metallic or non-metallic behavior was observed. A hopping conduction mechanism with an anomalous hopping exponent was detected in the non-metallic samples. All metallic delta-doped layers exhibited the same mobility value, around 3.6 ± 0.8 cm{sup 2}/Vs, independently of the layer thickness and the substrate type. Comparison with previously published data and theoretical calculations showed that scattering by ionized impurities explained only partially this low common value. None of the delta-layers showed any sign of confinement-induced mobility enhancement, even for thicknesses lower than 2 nm.

  2. Control of electron transfer kinetics at boron-doped diamond electrodes by specific surface modification

    OpenAIRE

    Duo, Ilaria; Comninellis, Christos

    2005-01-01

    Diamond films with different levels of doping have been the subject of applications and fundamental research in electrochemistry, opening up a new branch known as the electrochemistry of diamond. The electrochemical properties of diamond mostly depend on the operating conditions during the deposition of the film and on the treatment of the surface. The absence so far of a standard procedure in the production and treatment of diamond films has created a wide range of diamond quality and proper...

  3. Control of electron transfer kinetics at boron-doped diamond electrodes by specific surface modification

    OpenAIRE

    Duo, Ilaria

    2003-01-01

    Diamond films with different levels of doping have been the subject of applications and fundamental research in electrochemistry, opening up a new branch known as the electrochemistry of diamond. The electrochemical properties of diamond mostly depend on the operating conditions during the deposition of the film and on the treatment of the surface. The absence so far of a standard procedure in the production and treatment of diamond films has created a wide range of diamond quality and proper...

  4. Optical centers introduced in boron-doped synthetic diamond by near-threshold electron irradiation

    International Nuclear Information System (INIS)

    Near-threshold irradiation of B-doped synthetic diamonds has been performed using a transmission electron microscope operated at 200 kV. Both chemical vapor deposited and high-pressure high-temperature synthesized samples have been studied. The B levels were in the range 1017-1019 cm-3. After irradiation the samples were studied by low temperature (∼7 K) photoluminescence spectroscopy using various excitation wavelengths. A number of characteristic optical centers have been observed in the spectral range 500-800 nm and these centers are reviewed. Details of the properties of the optical centers have been investigated and the results are summarized. In particular, two zero-phonon lines (ZPLs) at 636 and 666 nm, formed in boron-doped diamond materials after near displacement-threshold electron radiation damage, were found to be related. The nature of this relationship is studied by laser power dependence (at different wavelengths) of their intensities over a wide temperature range. The results are interpreted in terms of a three-level model for a single optical center that involves a dipole-forbidden excited state of lower energy and a dipole-allowed state of 90 meV higher energy. Similar behavior of a further pair of ZPLs at 650 and 668 nm also formed in these materials is discussed. The spatial distribution of centers and their alteration by ultraviolet excitation was used to investigate the nature of the 636 and 666 nm centers

  5. Electronic and physico-chemical properties of nanometric boron delta-doped diamond structures

    International Nuclear Information System (INIS)

    Heavily boron doped diamond epilayers with thicknesses ranging from 40 to less than 2 nm and buried between nominally undoped thicker layers have been grown in two different reactors. Two types of [100]-oriented single crystal diamond substrates were used after being characterized by X-ray white beam topography. The chemical composition and thickness of these so-called delta-doped structures have been studied by secondary ion mass spectrometry, transmission electron microscopy, and spectroscopic ellipsometry. Temperature-dependent Hall effect and four probe resistivity measurements have been performed on mesa-patterned Hall bars. The temperature dependence of the hole sheet carrier density and mobility has been investigated over a broad temperature range (6 K 2/Vs, independently of the layer thickness and the substrate type. Comparison with previously published data and theoretical calculations showed that scattering by ionized impurities explained only partially this low common value. None of the delta-layers showed any sign of confinement-induced mobility enhancement, even for thicknesses lower than 2 nm

  6. Electrochemical Properties of Boron-Doped Diamond Electrodes Prepared by Hot Cathode Direct Current Plasma CVD

    Directory of Open Access Journals (Sweden)

    Hong Yan PENG

    2016-05-01

    Full Text Available A series of boron-doped diamond (BDD films were deposited by using a hot cathode direct current plasma chemical vapor deposition(HCDC-PCVD system with different ratios of CH4/H2/B(OCH33 (trimethylborate gas mixture. The morphology, structure and quality of BDD films were controled by SEM, XRD and Raman measurements. The electrochemical properties of the BDD films were investigated by electrochemical methods. Cyclic voltammetric performances of the BDD films indicated that the main determinant in the electrochemical characteristics of BDD films was the boron doping amount. The threshold potential for oxygen evolution increased from 1 V to 2.5 V. Meanwhile, the electrochemical potential window of BDD films was enlarged from 2.2 V to 4.5 V when the B content was increased from 1.75 × 1019cm-3 to 2.4 × 1021 cm−3. The cyclic voltammograms of BDD films in K4Fe(CN6 and K3Fe(CN6 mixed solution indicated that the behavior of Fe(CN6-3/-4 redox couple could be regarded as semi-reversible.DOI: http://dx.doi.org/10.5755/j01.ms.22.2.12926

  7. Synthesis and Temperature-dependent Electrochemical Properties of Boron-doped Diamond Electrodes on Titanium

    Institute of Scientific and Technical Information of China (English)

    DU Li-li; SUN Jian-rui; CUI Hang; LI Hong-dong; CUI Tian; LIN Hai-bo

    2012-01-01

    On the sand-blasting-treated titanium(Ti) substrate,the boron-doped diamond(BDD) electrodes with a wide potential window were prepared by microwave plasma chemical vapor deposition(MPCVD).The electrochemical oxidation ratios of phenol at BDD/Ti electrodes at elevated temperatures(from 20℃ to 80℃) were examined by the chemical oxygen demand(COD) of phenol electrolyte during electrolysis.The results show that the COD removal was increased at high temperatures and the optimized temperature for enhancing the electrochemical oxidation ratio of phenol is 60 ℃.The mechanism for the temperature-dependent electrochemical oxidation ratios of phenol at the electrodes was investigated.The study.would be favorable for further improving the performance of BDD/Ti electrodes,especially working at high temperatures.

  8. Electrochemical Biosensor Based on Boron-Doped Diamond Electrodes with Modified Surfaces

    Directory of Open Access Journals (Sweden)

    Yuan Yu

    2012-01-01

    Full Text Available Boron-doped diamond (BDD thin films, as one kind of electrode materials, are superior to conventional carbon-based materials including carbon paste, porous carbon, glassy carbon (GC, carbon nanotubes in terms of high stability, wide potential window, low background current, and good biocompatibility. Electrochemical biosensor based on BDD electrodes have attracted extensive interests due to the superior properties of BDD electrodes and the merits of biosensors, such as specificity, sensitivity, and fast response. Electrochemical reactions perform at the interface between electrolyte solutions and the electrodes surfaces, so the surface structures and properties of the BDD electrodes are important for electrochemical detection. In this paper, the recent advances of BDD electrodes with different surfaces including nanostructured surface and chemically modified surface, for the construction of various electrochemical biosensors, were described.

  9. Boron-Doped Nanocrystalline Diamond Electrodes for Neural Interfaces: In vivo Biocompatibility Evaluation.

    Science.gov (United States)

    Alcaide, María; Taylor, Andrew; Fjorback, Morten; Zachar, Vladimir; Pennisi, Cristian P

    2016-01-01

    Boron-doped nanocrystalline diamond (BDD) electrodes have recently attracted attention as materials for neural electrodes due to their superior physical and electrochemical properties, however their biocompatibility remains largely unexplored. In this work, we aim to investigate the in vivo biocompatibility of BDD electrodes in relation to conventional titanium nitride (TiN) electrodes using a rat subcutaneous implantation model. High quality BDD films were synthesized on electrodes intended for use as an implantable neurostimulation device. After implantation for 2 and 4 weeks, tissue sections adjacent to the electrodes were obtained for histological analysis. Both types of implants were contained in a thin fibrous encapsulation layer, the thickness of which decreased with time. Although the level of neovascularization around the implants was similar, BDD electrodes elicited significantly thinner fibrous capsules and a milder inflammatory reaction at both time points. These results suggest that BDD films may constitute an appropriate material to support stable performance of implantable neural electrodes over time. PMID:27013949

  10. Boron-doped nanocrystalline diamond electrodes for neural interfaces: In vivo biocompatibility evaluation

    Directory of Open Access Journals (Sweden)

    María eAlcaide

    2016-03-01

    Full Text Available Boron-doped nanocrystalline diamond (BDD electrodes have recently attracted attention as materials for neural electrodes due to their superior physical and electrochemical properties, however their biocompatibility remains largely unexplored. In this work, we aim to investigate the in vivo biocompatibility of BDD electrodes in relation to conventional titanium nitride (TiN electrodes using a rat subcutaneous implantation model. High quality BDD films were synthesized on electrodes intended for use as an implantable neurostimulation device. After implantation for 2 and 4 weeks, tissue sections adjacent to the electrodes were obtained for histological analysis. Both types of implants were contained in a thin fibrous encapsulation layer, the thickness of which decreased with time. Although the level of neovascularization around the implants was similar, BDD electrodes elicited significantly thinner fibrous capsules and a milder inflammatory reaction at both time points. These results suggest that BDD films may constitute an appropriate material to support stable performance of implantable neural electrodes over time.

  11. Electrochemical and morphological characterization of gold nanoparticles deposited on boron-doped diamond electrode

    Energy Technology Data Exchange (ETDEWEB)

    Limat, Meriadec; El Roustom, Bahaa [Ecole Polytechnique Federale de Lausanne (EPFL), Institute of Chemical Sciences and Engineering, CH-1015 Lausanne (Switzerland); Jotterand, Henri [Ecole Polytechnique Federale de Lausanne (EPFL), Institute of Physics of the Complex Matter, CH-1015 Lausanne (Switzerland); Foti, Gyoergy [Ecole Polytechnique Federale de Lausanne (EPFL), Institute of Chemical Sciences and Engineering, CH-1015 Lausanne (Switzerland)], E-mail: gyorgy.foti@epfl.ch; Comninellis, Christos [Ecole Polytechnique Federale de Lausanne (EPFL), Institute of Chemical Sciences and Engineering, CH-1015 Lausanne (Switzerland)

    2009-03-30

    A novel two-step method was employed to synthesize gold nanoparticles dispersed on boron-doped diamond (BDD) electrode. It consisted of sputter deposition at ambient temperature of maximum 15 equivalent monolayers of gold, followed by a heat treatment in air at 600 deg. C. Gold nanoparticles with an average diameter between 7 and 30 nm could be prepared by this method on polycrystalline BDD film electrode. The obtained Au/BDD composite electrode appeared stable under conditions of electrochemical characterization performed using ferri-/ferrocyanide and benzoquinone/hydroquinone redox couples in acidic medium. The electrochemical behavior of Au/BDD was compared to that of bulk Au and BDD electrodes. Finally, the Au/BDD composite electrode was regarded as an array of Au microelectrodes dispersed on BDD substrate.

  12. Covalent modification of boron-doped diamond electrodes with an imidazolium-based ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Wang Mei [Institut de Recherche Interdisciplinaire (IRI, USR 3078), Parc de la Haute Borne, 50 Avenue de Halley, BP 70478, 59658 Villeneuve d' Ascq (France); Institut d' Electronique, de Microelectronique et de Nanotechnologie (IEMN, UMR 8520), Cite Scientifique, Avenue Poincare, BP 60069, 59652 Villeneuve d' Ascq (France); School of Materials Science and Engineering, Shandong University, 19723 Jingshi Road, Jinan, Shandong Province (China); Schneider, Amene [Austrian Centre of Competence for Tribology, Viktor Kaplan Strasse 2, 2700, Wiener Neustadt (Austria); Niedziolka-Joensson, Joanna; Marcon, Lionel [Institut de Recherche Interdisciplinaire (IRI, USR 3078), Parc de la Haute Borne, 50 Avenue de Halley, BP 70478, 59658 Villeneuve d' Ascq (France); Institut d' Electronique, de Microelectronique et de Nanotechnologie (IEMN, UMR 8520), Cite Scientifique, Avenue Poincare, BP 60069, 59652 Villeneuve d' Ascq (France); Ghodbane, Slimane; Steinmueller-Nethl, Doris [Rho-BeSt Coating GmbH, Exlgasse 20a, 6020 Innsbruck (Austria); Li Musen [School of Materials Science and Engineering, Shandong University, 19723 Jingshi Road, Jinan, Shandong Province (China); Boukherroub, Rabah [Institut de Recherche Interdisciplinaire (IRI, USR 3078), Parc de la Haute Borne, 50 Avenue de Halley, BP 70478, 59658 Villeneuve d' Ascq (France); Institut d' Electronique, de Microelectronique et de Nanotechnologie (IEMN, UMR 8520), Cite Scientifique, Avenue Poincare, BP 60069, 59652 Villeneuve d' Ascq (France); Szunerits, Sabine, E-mail: sabine.szunerits@iri.univ-lille1.f [Institut de Recherche Interdisciplinaire (IRI, USR 3078), Parc de la Haute Borne, 50 Avenue de Halley, BP 70478, 59658 Villeneuve d' Ascq (France); Institut d' Electronique, de Microelectronique et de Nanotechnologie (IEMN, UMR 8520), Cite Scientifique, Avenue Poincare, BP 60069, 59652 Villeneuve d' Ascq (France)

    2010-02-01

    An ionic liquid (IL, 1-(methylcarboxylic acid)-3-octylimidazolium-bis (trifluoromethylsulfonyl)imide) was covalently coupled onto a boron-doped diamond (BDD) surface through an esterification reaction. The resulting surface was characterized by X-ray photoelectron spectroscopy, water contact angle and electrochemical measurements. Selective electron transfer towards positively and negatively charged redox species was recorded. While the presence of Fe(CN){sub 6}{sup 4-} could be detected on the IL-modified BDD interface, no surface-immobilized Ru(NH{sub 3}){sub 6}{sup 3+} was recorded. The IL-modified BDD electrode showed in addition changes in surface wettability when immersed into aqueous solution containing different anions.

  13. Preparation and reactivity of carboxylic acid-terminated boron-doped diamond electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Niedziolka-Joensson, Joanna [Institut de Recherche Interdisciplinaire (IRI, USR 3078), Parc de la Haute Borne, 50 Avenue de Halley, BP 70478, 59658 Villeneuve d' Ascq (France); Institut d' Electronique, de Microelectronique et de Nanotechnologie (IEMN, UMR 8520), Cite Scientifique, Avenue Poincare, BP 60069, 59652 Villeneuve d' Ascq (France); Boland, Susan; Leech, Donal [School of Chemistry, National University of Irland, Galway (Ireland); Boukherroub, Rabah [Institut de Recherche Interdisciplinaire (IRI, USR 3078), Parc de la Haute Borne, 50 Avenue de Halley, BP 70478, 59658 Villeneuve d' Ascq (France); Institut d' Electronique, de Microelectronique et de Nanotechnologie (IEMN, UMR 8520), Cite Scientifique, Avenue Poincare, BP 60069, 59652 Villeneuve d' Ascq (France); Szunerits, Sabine, E-mail: sabine.szunerits@iri.univ-lille1.f [Institut de Recherche Interdisciplinaire (IRI, USR 3078), Parc de la Haute Borne, 50 Avenue de Halley, BP 70478, 59658 Villeneuve d' Ascq (France); Institut d' Electronique, de Microelectronique et de Nanotechnologie (IEMN, UMR 8520), Cite Scientifique, Avenue Poincare, BP 60069, 59652 Villeneuve d' Ascq (France)

    2010-01-01

    The paper reports on the formation of carboxy-terminated boron-doped diamond (BDD) electrodes. The carboxylic acid termination was prepared in a controlled way by reacting photochemically oxidized BDD with succinic anhydride. The resulting interface was readily employed for the linking of an amine-terminated ligand such as an osmium complex bearing an amine terminal group. The interfaces were characterized using X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV). Contact angle measurements were used to follow the changes in surface wetting properties due to surface functionalization. The chemical reactivity of the carboxyl-terminated BDD was investigated by covalent coupling of the acid groups to an amine-terminated osmium complex.

  14. Boron-doped diamond anodic oxidation of ethidium bromide: Process optimization by response surface methodology

    International Nuclear Information System (INIS)

    Highlights: ► Boron-doped diamond was used to degrade ethidium bromide. ► The process was optimized by a central composite rotatable design coupled with response surface methodology. ► Applied current is proved to be the most significant variable. ► A possible reaction sequence involving all the detected byproducts was proposed. - Abstract: The degradation of ethidium bromide (EtBr), a DNA intercalating pollutant, had been studied by anodic oxidation on boron-doped diamond (BDD) electrode under galvanostatic conditions. A central composite rotatable design coupled with response surface methodology was implemented to optimize the various operating parameters involved, among initial pH, flow rate, applied current and supporting electrolyte concentration, on the treatment efficiency; the latter was assessed in terms of color removal, COD removal, specific energy consumption and general current efficiency. Of the four parameters involved, applied current had a considerable effect on all the response factors. Optimum EtBr degradation was achieved by applying a current of 0.90 A, 9.0 mM Na2SO4, flow rate of 400 ml min−1 and pH 6.2 at 60 min of electrolysis, being reduced color by 80.2% and COD by 29.7%, with an energy consumption of 398.32 kW h (kg COD)−1 and a general current efficiency of 10.1%. Under these optimized conditions, EtBr decays followed pseudo first-order kinetics. Moreover, HPLC analysis of the BDD-treated solution allowed the detection of a number of reaction intermediates, and a possible reaction sequence involving all the detected byproducts was proposed for the electrochemical oxidation of EtBr on BDD anode.

  15. Electroanalytical determination of estriol hormone using a boron-doped diamond electrode.

    Science.gov (United States)

    Santos, Keliana D; Braga, Otoniel C; Vieira, Iolanda C; Spinelli, Almir

    2010-03-15

    A boron-doped diamond (BDD) electrode was used for the electroanalytical determination of estriol hormone in a pharmaceutical product and a urine sample taken during pregnancy by square-wave voltammetry. The optimized experimental conditions were: (1) a supporting electrolyte solution of NaOH at a pH of 12.0, and (2) a frequency of 20 Hz, a pulse height of 30 mV and a scan increment of 2 mV (for the square-wave parameters). The analytical curve was linear in the concentration range of 2.0 x 10(-7) to 2.0 x 10(-5) mol L(-1) (r=0.9994), with a detection limit of 1.7 x 10(-7) mol L(-1) and quantification limit of 8.5 x 10(-7) mol L(-1). Recoveries of estriol were in the range of 98.6-101.0%, for the pharmaceutical sample, and 100.2-103.4% for the urine sample, indicating no significant matrix interference effects on the analytical results. The accuracy of the electroanalytical methodology proposed was compared to that of the radioimmunoassay method. The values for the relative error between the proposed and standard methods were -7.29% for the determination of estriol in the commercial product and -4.98% in a urine sample taken during pregnancy. The results obtained suggest a reliable and interesting alternative method for electroanalytical determination of estriol in pharmaceutical products and urine samples taken during pregnancy using a boron-doped diamond electrode.

  16. Doped diamond electrodes on titanium substrates with controlled sp2/sp3 hybridization at different boron levels

    International Nuclear Information System (INIS)

    Doped diamond films on titanium substrate were systematically studied by controlling their sp2/sp3 hybridization as well as their boron doping levels. Samples were grown by hot filament chemical vapor deposition technique at CH4 additions of 1, 2, 6 and 10 sccm diluted in H2 for a total flow rate of 200 sccm. For each CH4 concentration four doping levels were studied. The boron source was obtained from a constant flow of 40 sccm for an additional H2 line passing through a bubbler containing the B2O3 dissolved in methanol with B/C ratios of 2000, 7000, 15,000, and 30,000 B/C ppm. Scanning electron microscopy images depicted well faceted films without cracks or delaminations. The sp2/sp3 ratio as “purity index” (PI) and the “growth tendency index” (GTI), associated to the TiC formation, were evaluated by Raman and X-ray spectra, respectively. GTI index was used in this work to analyze the competition between the diamond growth and TiC formation. It is also possible to associate the GTI index in terms of C/H ratio, since when this ratio is increased, the GTI index also increased. A constant GTI increase was observed as a function of CH4 addition for the whole range of the boron doping studied. For PI, an optimized value was observed at 6 sccm of CH4 for the doping levels higher than 2000 ppm of B/C ratio. - Highlights: • Control of experimental parameters to obtain good quality diamond films. • sp2 bond influence on the doping level of diamond films. • Systematic analysis of diamond growth process on Ti substrate

  17. Direct electrochemistry of blue copper proteins at boron-doped diamond electrodes

    Energy Technology Data Exchange (ETDEWEB)

    McEvoy, James P. [Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA (United Kingdom); Foord, John S. [Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA (United Kingdom)]. E-mail: john.foord@chem.ox.ac.uk

    2005-05-05

    Boron-doped diamond (BDD) is a promising electrode material for use in the spectro-electrochemical study of redox proteins and, in this investigation, cyclic voltammetry was used to obtain quasi-reversible electrochemical responses from two blue copper proteins, parsley plastocyanin and azurin from Pseudomonas aeruginosa. No voltammetry was observed at the virgin electrodes, but signals were observed if the electrodes were anodised, or abraded with alumina, prior to use. Plastocyanin, which has a considerable overall negative charge and a surface acidic patch which is important in forming a productive electron transfer complex with its redox partners, gave a faradaic signal at pre-treated BDD only in the presence of neomycin, a positively charged polyamine. The voltammetry of azurin, which has a small overall charge and no surface acidic patch, was obtained identically in the presence and absence of neomycin. Investigations were also carried out into the voltammetry of two site-directed mutants of azurin, M64E azurin and M44K azurin, each of which introduce a charge into the protein's surface hydrophobic patch. The oxidizing and cleaning effects of the BDD electrode pre-treatments were studied electrochemically using two inorganic probe ions, Fe(China){sub 6} {sup 3-} and Ru(NH{sub 3}){sub 6} {sup 3+}, and by X-ray photoelectron spectroscopy (XPS). All of the electrochemical results are discussed in relation to the electrostatic and hydrophobic contributions to the protein/diamond electrochemical interaction.

  18. Amperometric oxygen sensor based on a platinum nanoparticle-modified polycrystalline boron doped diamond disk electrode.

    Science.gov (United States)

    Hutton, Laura; Newton, Mark E; Unwin, Patrick R; Macpherson, Julie V

    2009-02-01

    Pt nanoparticle (NP)-modified polycrystalline boron-doped diamond (pBDD) disk electrodes have been fabricated and employed as amperometric sensors for the determination of dissolved oxygen concentration in aqueous solution. pBDD columns were cut using laser micromachining techniques and sealed in glass, in order to make disk electrodes which were then characterized electrochemically. Electrodeposition of Pt onto the diamond electrodes was optimized so as to give the maximum oxygen reduction peak current with the lowest background signal. Pt NPs, >0-10 nm diameter, were found to deposit randomly across the pBDD electrode, with no preference for grain boundaries. The more conductive grains were found to promote the formation of smaller nanoparticles at higher density. With the use of potential step chronoamperometry, in which the potential was stepped to a diffusion-limited value, a four electron oxygen reduction process was found to occur at the Pt NP-modified pBDD electrode. Furthermore the chronoamperometric response scaled linearly with dissolved oxygen concentration, varied by changing the oxygen/nitrogen ratio of gas flowed into solution. The sensor was used to detect dissolved oxygen concentrations with high precision over the pH range 4-10. PMID:19117391

  19. Biofouling resistance of boron-doped diamond neural stimulation electrodes is superior to titanium nitride electrodes in vivo

    DEFF Research Database (Denmark)

    Meijs, Suzan; Alcaide, Maria; Sørensen, Charlotte;

    2016-01-01

    OBJECTIVE: The goal of this study was to assess the electrochemical properties of boron-doped diamond (BDD) electrodes in relation to conventional titanium nitride (TiN) electrodes through in vitro and in vivo measurements. APPROACH: Electrochemical impedance spectroscopy, cyclic voltammetry and ...... electrodes possess a superior biofouling resistance, which provides significantly stable electrochemical properties both in protein solution as well as in vivo compared to TiN electrodes....

  20. Voltammetric method for sensitive determination of herbicide picloram in environmental and biological samples using boron-doped diamond film electrode

    International Nuclear Information System (INIS)

    The voltammetric behavior and determination of picloram, a member of a pyridine herbicide family, was for the first time investigated on a boron doped diamond film electrode using cyclic and differential pulse voltammetry. The influence of supporting electrolyte and scan rate on the current response of picloram was examined to select the optimum experimental conditions. It was found that picloram provided one well-shaped oxidation peak at very positive potential (+1.5 V vs. Ag/AgCl electrode) in strong acidic medium. At optimized differential pulse voltammetric parameters, the current response of picloram was proportionally linear in the concentration range from 0.5 to 48.07 μmol L−1 and the low limit of detection of 70 nmol L−1 as well as good repeatability (relative standard deviation of 2.6% at 10 μmol L−1 for n = 11) were obtained on unmodified boron-doped diamond film electrode. The proposed method was successfully applied in analysis of environmental (tap and natural water) and biological (human urine) samples spiked with picloram with good accuracy (relative standard deviations less than 5% for all samples, n = 5). By this way, the boron-doped diamond could introduce a green (environmentally acceptable) alternative to mercury electrodes for the monitoring of herbicides

  1. Electroanalytical investigation and determination of pefloxacin in pharmaceuticals and serum at boron-doped diamond and glassy carbon electrodes.

    Science.gov (United States)

    Uslu, Bengi; Topal, Burcu Dogan; Ozkan, Sibel A

    2008-02-15

    The anodic behavior and determination of pefloxacin on boron-doped diamond and glassy carbon electrodes were investigated using cyclic, linear sweep, differential pulse and square wave voltammetric techniques. In cyclic voltammetry, pefloxacin shows one main irreversible oxidation peak and additional one irreversible ill-defined wave depending on pH values for both electrodes. The results indicate that the process of pefloxacin is irreversible and diffusion controlled on boron-doped diamond electrode and irreversible but adsorption controlled on glassy carbon electrode. The peak current is found to be linear over the range of concentration 2x10(-6) to 2x10(-4)M in 0.5M H(2)SO(4) at about +1.20V (versus Ag/AgCl) for differential pulse and square wave voltammetric technique using boron-doped diamond electrode. The repeatability, reproducibility, precision and accuracy of the methods in all media were investigated. Selectivity, precision and accuracy of the developed methods were also checked by recovery studies. The procedures were successfully applied to the determination of the drug in pharmaceutical dosage forms and humans serum samples with good recovery results. No electroactive interferences from the excipients and endogenous substances were found in the pharmaceutical dosage forms and biological samples, respectively.

  2. EFFECT OF POLISHING ON THE FRICTION BEHAVIORS AND CUTTING PERFORMANCE OF BORON-DOPED DIAMOND FILMS ON WC-Co INSERTS

    OpenAIRE

    LIANG WANG; BIN SHEN; FANGHONG SUN; ZHIMING ZHANG

    2014-01-01

    Boron doped (B-doped) diamond films are deposited onto WC-Co inserts by HFCVD with the mixture of acetone, trimethyl borate (C3H9BO3) and H2. The as-deposited B-doped diamond films are characterized with scanning electron microscope (SEM), X-ray diffraction (XRD) spectroscopy, Raman spectroscopy, 3D surface topography based on white-light interferometry and Rockwell hardness tester. The effects of mechanical polishing on the friction behavior and cutting performance of B-doped diamond are eva...

  3. Functionalization of boron-doped nanocrystalline diamond with N3 dye molecules.

    Science.gov (United States)

    Yeap, W S; Liu, X; Bevk, D; Pasquarelli, A; Lutsen, L; Fahlman, M; Maes, W; Haenen, K

    2014-07-01

    N3 dye molecules [cis-bis(isothiocyanato)bis(2,2'-bipyridyl-4,4'-dicarboxylato)ruthenium(II)] are covalently attached to boron-doped nanocrystalline diamond (B:NCD) thin films through a combination of coupling chemistries, i.e., diazonium, Suzuki, and EDC-NHS. X-ray and ultraviolet photoelectron spectroscopy and near-edge X-ray absorption fine structure spectroscopy are used to verify the covalent bonding of the dye on the B:NCD surface (compared to a hydrogen-terminated reference). The spectroscopic results confirm the presence of a dense N3 chromophore layer, and the positions of the frontier orbitals of the dye relative to the band edge of the B:NCD thin film are inferred as well. Proof-of-concept photoelectrochemical measurements show a strong increase in the photocurrent compared to non-dye-functionalized B:NCD films. This study opens up the possibility of applying N3-sensitized B:NCD thin films as hole conductors in dye-sensitized solar cells. PMID:24915549

  4. Mineralization of bisphenol A (BPA) by anodic oxidation with boron-doped diamond (BDD) electrode

    Energy Technology Data Exchange (ETDEWEB)

    Murugananthan, M. [Satellite Venture Business Laboratory, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585 (Japan)], E-mail: muruga.chem@gmail.com; Yoshihara, S. [Department of Energy and Environmental Science, Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585 (Japan)], E-mail: sachioy@cc.utsunomiya-u.ac.jp; Rakuma, T.; Shirakashi, T. [Department of Energy and Environmental Science, Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585 (Japan)

    2008-06-15

    Anodic oxidation of bisphenol A (BPA), a representative endocrine disrupting chemical, was carried out using boron-doped diamond (BDD) electrode at galvanostatic mode. The electro-oxidation behavior of BPA at BDD electrode was investigated by means of cyclic voltammetric technique. The extent of degradation and mineralization of BPA were monitored by HPLC and total organic carbon (TOC) value, respectively. The results obtained, indicate that the BPA removal at BDD depends on the applied current density (I{sub appl}), initial concentration of BPA, pH of electrolyte and supporting medium. Galvanostatic electrolysis at BDD anode cause concomitant generation of hydroxyl radical that leads to the BPA destruction. The kinetics for the BPA degradation follows a pseudo-first order reaction with a higher rate constant 12.8 x 10{sup -5} s{sup -1} for higher I{sub appl} value 35.7 mA cm{sup -2}, indicating that the oxidation reaction is limited by I{sub appl} control. Complete mineralization of BPA was achieved regardless of the variables and accordingly the mineralization current efficiency was calculated from the TOC removal measurements. Considering global oxidation process, the effect of supporting electrolytes has been discussed in terms of the electro generated inorganic oxidants. The better performance of BDD anode was proved on a comparative study with Pt and glassy carbon under similar experimental conditions. A possible reaction mechanism for BPA degradation involving three main aromatic intermediates, identified by GC-MS analysis, was proposed.

  5. Electrochemical treatment of cork boiling wastewater with a boron-doped diamond anode.

    Science.gov (United States)

    Fernandes, Annabel; Santos, Diana; Pacheco, Maria José; Ciríaco, Lurdes; Simões, Rogério; Gomes, Arlindo C; Lopes, Ana

    2015-01-01

    Anodic oxidation at a boron-doped diamond anode of cork boiling wastewater was successfully used for mineralization and biodegradability enhancement required for effluent discharge or subsequent biological treatment, respectively. The influence of the applied current density (30-70 mA/cm2) and the background electrolyte concentration (0-1.5 g/L Na2SO4) on the performance of the electrochemical oxidation was investigated. The supporting electrolyte was required to achieve conductivities that enabled anodic oxidation at the highest current intensities applied. The results indicated that pollutant removal increased with the applied current density, and after 8 h, reductions greater than 90% were achieved for COD, dissolved organic carbon, total phenols and colour. The biodegradability enhancement was from 0.13 to 0.59 and from 0.23 to 0.72 for the BOD/COD ratios with BOD of 5 and 20 days' incubation period, respectively. The tests without added electrolyte were performed at lower applied electrical charges (15 mA/cm2 or 30 V) with good organic load removal (up to 80%). For an applied current density of 30 mA/cm2, there was a minimum of electric conductivity of 1.9 mS/cm (corresponding to 0.75 g/L of Na2SO4), which minimized the specific energy consumption.

  6. Anodic oxidation of textile dyehouse effluents on boron-doped diamond electrode

    Energy Technology Data Exchange (ETDEWEB)

    Tsantaki, Eleni; Velegraki, Theodora; Katsaounis, Alexandros [Department of Environmental Engineering, Technical University of Crete, Polytechneioupolis, GR-73100 Chania (Greece); Mantzavinos, Dionissios, E-mail: mantzavi@mred.tuc.gr [Department of Environmental Engineering, Technical University of Crete, Polytechneioupolis, GR-73100 Chania (Greece)

    2012-03-15

    The electrochemical oxidation of textile effluents over a boron-doped diamond anode was investigated in the present study. Experiments were conducted with a multi-component synthetic solution containing seventeen dyes and other auxiliary inorganics, as well as an actual effluent from a textile dyeing process. The effect of varying operating parameters, such as current density (4-50 mA/cm{sup 2}), electrolyte concentration (0.1-0.5 M HClO{sub 4}), initial solution pH (1-12.3) and temperature (22-43 Degree-Sign C), on process efficiency was investigated following changes in total organic carbon (TOC), chemical oxygen demand (COD) and color. Complete decolorization accompanied by significant mineralization (up to 85% depending on the conditions) could be achieved after 180 min of treatment. Performance was improved at higher electrolyte concentrations and lower pH values, while the effect of temperature was marginal. Energy consumption per unit mass of COD removed was favored at lower current densities, since energy was unnecessarily wasted to side reactions at higher densities.

  7. Microfluidic platform for environmental contaminants sensing and degradation based on boron-doped diamond electrodes.

    Science.gov (United States)

    Medina-Sánchez, Mariana; Mayorga-Martinez, CarmenC; Watanabe, Takeshi; Ivandini, TribidasariA; Honda, Yuki; Pino, Flavio; Nakata, Kazuya; Fujishima, Akira; Einaga, Yasuaki; Merkoçi, Arben

    2016-01-15

    We have developed a lab-on-a-chip (LOC) platform for electrochemical detection and degradation of the pesticide atrazine (Atz). It is based on boron-doped diamond (BDD) electrodes and a competitive magneto-enzyme immunoassay (EIA) that enables high sensitivity. To detect the enzymatic reaction, we employed a BDD electrode modified with platinum nanoparticles (PtNPs), as a highly conductive catalytic transducer. Chronoamperometry revealed a limit of detection (LOD) of 3.5 pM for atrazine, which, to the best of our knowledge, is one of the lowest value published to date. Finally, we degraded Atz in the same platform, using a bare BDD electrode that features remarkable corrosion stability, a wide potential window, and much higher O2 overvoltage as compared to conventional electrodes. These characteristics enable the electrode to produce a greater amount of HO• on the anode surface than do conventional electrodes and consequently, to destroy the pollutant more rapidly. Our new LOC platform might prove interesting as a smart system for detection and remediation of diverse pesticides and other contaminants. PMID:26339934

  8. Mineralization of bisphenol A (BPA) by anodic oxidation with boron-doped diamond (BDD) electrode

    International Nuclear Information System (INIS)

    Anodic oxidation of bisphenol A (BPA), a representative endocrine disrupting chemical, was carried out using boron-doped diamond (BDD) electrode at galvanostatic mode. The electro-oxidation behavior of BPA at BDD electrode was investigated by means of cyclic voltammetric technique. The extent of degradation and mineralization of BPA were monitored by HPLC and total organic carbon (TOC) value, respectively. The results obtained, indicate that the BPA removal at BDD depends on the applied current density (Iappl), initial concentration of BPA, pH of electrolyte and supporting medium. Galvanostatic electrolysis at BDD anode cause concomitant generation of hydroxyl radical that leads to the BPA destruction. The kinetics for the BPA degradation follows a pseudo-first order reaction with a higher rate constant 12.8 x 10-5 s-1 for higher Iappl value 35.7 mA cm-2, indicating that the oxidation reaction is limited by Iappl control. Complete mineralization of BPA was achieved regardless of the variables and accordingly the mineralization current efficiency was calculated from the TOC removal measurements. Considering global oxidation process, the effect of supporting electrolytes has been discussed in terms of the electro generated inorganic oxidants. The better performance of BDD anode was proved on a comparative study with Pt and glassy carbon under similar experimental conditions. A possible reaction mechanism for BPA degradation involving three main aromatic intermediates, identified by GC-MS analysis, was proposed

  9. Electrochemical determination of bisphenol A using a boron-doped diamond electrode

    International Nuclear Information System (INIS)

    An electrochemical method was developed for the determination of bisphenol A (BPA) at an unmodified boron-doped diamond (BDD) electrode using differential pulse voltammetry (DPV). The sensitivity of the DPV measurements was significantly improved by using a predominantly hydrogen-terminated BDD electrode obtained by a cathodic pretreatment. A highly linear analytical curve was obtained for BPA determination in the range of 0.44–5.2 μmol L−1, with quantification and detection limits of 0.71 μmol L−1 and 0.21 μmol L−1, respectively. After assuring that the results obtained with the developed DPV method did not change in the presence of possible interferents, the method was successfully applied to monitor the concentration of BPA as it was electrooxidized in a flow reactor with an Nb/BDD anode. As far as it could be verified, the proposed electroanalytical method is the first one based on the use of an unmodified electrode.

  10. Bioelectrochemical degradation of urea at platinized boron doped diamond electrodes for bioregenerative systems

    Science.gov (United States)

    Nicolau, Eduardo; González-González, Ileana; Flynn, Michael; Griebenow, Kai; Cabrera, Carlos R.

    2009-10-01

    The recovery of potable water from space mission wastewater is critical for the life support and environmental health of crew members in long-term missions. NASA estimates reveal that at manned space missions 1.91 kg/person day of urine is produced, with urea and various salts as its main components. In this research we explore the utilization of urease (EC 3.5.1.5, 15,000 U/g) along with a platinized boron doped diamond electrode (Pt-BDD) to degrade urea. Urea is directly degraded to nitrogen by the in situ utilization of the reaction products as a strategy to increase the amount of clean water in future space expeditions. The biochemical reaction of urease produces ammonia and carbon dioxide from urea. Thereafter, ammonia is electrooxidized at the interface of the Pt-BDD producing molecular nitrogen. The herein presented system has been proven to have 20% urea conversion efficiency. This research has potential applications for future long-term space missions since the reaction byproducts could be used for a biomass subsystem (in situ resource recovery), while generating electricity from the same process.

  11. Electrochemical incineration of sulfanilic acid at a boron-doped diamond anode.

    Science.gov (United States)

    El-Ghenymy, Abdellatif; Arias, Conchita; Cabot, Pere Lluís; Centellas, Francesc; Garrido, José Antonio; Rodríguez, Rosa María; Brillas, Enric

    2012-06-01

    The anodic oxidation of sulfanilic acid solutions has been studied in acidic medium using a divided cell with a boron-doped diamond (BDD) anode and a stainless steel cathode. Overall mineralization was achieved under all experimental conditions tested due to the efficient destruction of sulfanilic acid and all its by-products with hydroxyl radicals generated at the BDD anode from water oxidation. The alternative use of an undivided cell with the same electrodes gave rise to the coating of the cathode with polymeric compounds, thus preventing the complete electrochemical incineration of sulfanilic acid. The solutions treated in the anodic compartment of the divided cell were degraded at similar rate under pH regulation within the pH interval 2.0-6.0. The mineralization current efficiency was enhanced when the applied current decreased and the initial substrate concentration increased. The decay of sulfanilic acid was followed by reversed-phase HPLC, showing a pseudo first-order kinetics. Hydroquinone and p-benzoquinone were identified as aromatic intermediates by gas chromatography-mass spectrometry and/or reversed-phase HPLC. Maleic, acetic, formic, oxalic and oxamic acids were detected as generated carboxylic acids by ion-exclusion HPLC. Ionic chromatographic analysis of electrolyzed solutions revealed that the N content of sulfanilic acid was mainly released as NH(4)(+) ion and in much smaller proportion as NO(3)(-) ion.

  12. Electrochemical decolorization of dye wastewater by surface-activated boron-doped nanocrystalline diamond electrode.

    Science.gov (United States)

    Chen, Chienhung; Nurhayati, Ervin; Juang, Yaju; Huang, Chihpin

    2016-07-01

    Complex organics contained in dye wastewater are difficult to degrade and often require electrochemical advanced oxidation processes (EAOPs) to treat it. Surface activation of the electrode used in such treatment is an important factor determining the success of the process. The performance of boron-doped nanocrystalline diamond (BD-NCD) film electrode for decolorization of Acid Yellow (AY-36) azo dye with respect to the surface activation by electrochemical polarization was studied. Anodic polarization found to be more suitable as electrode pretreatment compared to cathodic one. After anodic polarization, the originally H-terminated surface of BD-NCD was changed into O-terminated, making it more hydrophilic. Due to the oxidation of surface functional groups and some portion of sp(2) carbon in the BD-NCD film during anodic polarization, the electrode was successfully being activated showing lower background current, wider potential window and considerably less surface activity compared to the non-polarized one. Consequently, electrooxidation (EO) capability of the anodically-polarized BD-NCD to degrade AY-36 dye was significantly enhanced, capable of nearly total decolorization and chemical oxygen demand (COD) removal even after several times of re-using. The BD-NCD film electrode favored acidic condition for the dye degradation; and the presence of chloride ion in the solution was found to be more advantageous than sulfate active species. PMID:27372123

  13. Direct and Simultaneous Determination of Phenol, Hydroquinone and Nitrophenol at Boron-Doped Diamond Film Electrode

    Institute of Scientific and Technical Information of China (English)

    ZHAO, Guo-Hua; TANG, Yi-Ting; LIU, Mei-Chuan; LEI, Yan-Zhu; XIAO, Xiao-E

    2007-01-01

    The electrochemical characteristics of multi-component phenolic pollutants, such as phenol (Ph), hydroquinone (HQ) and 4-nitrophenol (4-NP), were investigated on boron-doped diamond (BDD) film electrode by differential pulse voltammetry (DPV) technique. A simple and feasible platform was accordingly established for the direct and simultaneous determination of these three phenolic pollutants. Results showed that, Ph, HQ and 4-NP gave obvious oxidation peaks on BDD electrode at the potential of 1.24, 0.76 and 1.52 V, respectively. Each of them displayed good linear relationship between their oxidation peak currents and their corresponding concentrations in a rather wide range coexisting with one or two of the other phenolic pollutants. The detection limits of Ph, HQ and 4-NP were estimated to be as low as 1.82×10-6, 1.67×10-6 and 1.44×10-6mol·L-1, respectively. Therefore, a promising direct and simultaneous electrochemical determination method of multi-component phenolic pollutants in wastewater samples was constructed successfully on BDD electrode with advantages being rapid, simple, convenient, sensitive, in situ and inexpensive.

  14. Electrochemical oxidation of oxalic acid in the presence of halides at boron doped diamond electrode

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Huitle, C.A. [University of Milan, Milan (Italy). Dept. of Analytical Chemistry]. E-mail: Carlos.Martinez@unimi.it; Ferro, S.; Battisti, A. de [University of Ferrara (Italy). Dept. of Chemistry. Lab. of Electrochemistry; Reyna, S.; Cerro-Lopez, M.; Quiroz, M.A. [Universidad de las Americas-Puebla, Puebla (Mexico). Dept. de Quimica y Biologia. Lab. de Electroquimica]. E-mail: marcoa.quiroz@udlap.mx

    2008-07-01

    Aim of this work is to discuss the electrochemical oxidation of oxalic acid (OA), analyzing the influence of NaCl and NaBr. Experiments were carried out at boron-doped diamond (BDD) electrodes, in alkaline media. BDD electrodes have a poor superficial adsorptivity so their great stability toward oxidation allows the reaction to take place with reactants and intermediates in a non-adsorbed state. The process is significantly accelerated by the presence of a halogen salt in solution; interestingly, the mediated process does not depend on applied current density. Based on the results, bromide was selected as a suitable mediator during OA oxidation at BDD. Br{sup -} primarily acts in the volume of the solution, with the formation of strong oxidants; while Cl{sup -} action has shown lower improvements in the OA oxidation rate at BDD respect to the results reported using Pt electrode. Finally, the parameters of removal efficiency and energy consumption for the electrochemical incineration of OA were calculated. (author)

  15. Electrochemical incineration of dimethyl phthalate by anodic oxidation with boron-doped diamond electrode

    Institute of Scientific and Technical Information of China (English)

    HOU Yining; QU Jiuhui; ZHAO Xu; LIU Huijuan

    2009-01-01

    The anodic oxidation of aqueous solutions containing dimethyl phthalate (DMP) up to 125 mg/L with sodium sulfate (Na2SO4) as supporting electrolyte within the pH range 2.0-10.0 was studied using a one-compartment batch reactor employing a boron-doped diamond (BDD) as anode. Electrolyses were carried out at constant current density (1.5-4.5 mA/cm2). Complete mineralization was always achieved owing to the great concentration of hydroxyl radical (·OH) generated at the BDD surface. The effect of pH, apparent current density and initial DMP concentration on the degradation rate of DMP, the specific charge required for its total mineralization and mineralization current efficiency was investigated systematically. The mineralization rate of DMP was found to be pH-independent and to increase with increasing applied current density. Results indicated that this electrochemical process was subjected, at least partially, to the mass transfer of organics onto the BDD surface. Kinetic analysis of the temporal change of DMP concentration during electrolysis determined by High Performance Liquid Chromatography (HPLC) revealed that DMP decay under all tested conditions followed a pseudo first-order reaction. Aromatic intermediates and generated carboxylic acids were identified by Gas Chromatography-Mass Spectrometry (GC-MS) and a general pathway for the electrochemical incineration of DMP on BDD was proposed.

  16. Electrochemical oxidation of biological pretreated and membrane separated landfill leachate concentrates on boron doped diamond anode

    Science.gov (United States)

    Zhou, Bo; Yu, Zhiming; Wei, Qiuping; Long, HangYu; Xie, Youneng; Wang, Yijia

    2016-07-01

    In the present study, the high quality boron-doped diamond (BDD) electrodes with excellent electrochemical properties were deposited on niobium (Nb) substrates by hot filament chemical vapor deposition (HFCVD) method. The electrochemical oxidation of landfill leachate concentrates from disc tube reverse osmosis (DTRO) process over a BDD anode was investigated. The effects of varying operating parameters, such as current density, initial pH, flow velocity and cathode material on degradation efficiency were also evaluated following changes in chemical oxygen demand (COD) and ammonium nitrogen (NH3sbnd N). The instantaneous current efficiency (ICE) was used to appraise different operating conditions. As a result, the best conditions obtained were as follows, current density 50 mA cm-2, pH 5.16, flow velocity 6 L h-1. Under these conditions, 87.5% COD and 74.06% NH3sbnd N removal were achieved after 6 h treatment, with specific energy consumption of 223.2 kWh m-3. In short, these results indicated that the electrochemical oxidation with BDD/Nb anode is an effective method for the treatment of landfill leachate concentrates.

  17. Continuous and selective measurement of oxytocin and vasopressin using boron-doped diamond electrodes.

    Science.gov (United States)

    Asai, Kai; Ivandini, Tribidasari A; Einaga, Yasuaki

    2016-01-01

    The electrochemical detection of oxytocin using boron-doped diamond (BDD) electrodes was studied. Cyclic voltammetry of oxytocin in a phosphate buffer solution exhibits an oxidation peak at +0.7 V (vs. Ag/AgCl), which is attributable to oxidation of the phenolic group in the tyrosyl moiety. Furthermore, the linearity of the current peaks obtained in flow injection analysis (FIA) using BDD microelectrodes over the oxytocin concentration range from 0.1 to 10.0 μM with a detection limit of 50 nM (S/N = 3) was high (R(2) = 0.995). Although the voltammograms of oxytocin and vasopressin observed with an as-deposited BDD electrode, as well as with a cathodically-reduced BDD electrode, were similar, a clear distinction was observed with anodically-oxidized BDD electrodes due to the attractive interaction between vasopressin and the oxidized BDD surface. By means of this distinction, selective measurements using chronoamperometry combined with flow injection analysis at an optimized potential were demonstrated, indicating the possibility of making selective in situ or in vivo measurements of oxytocin. PMID:27599852

  18. Electrochemical degradation of chlorobenzene on boron-doped diamond and platinum electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Liu Lei [Department of Chemistry, Tongji University, Shanghai, 200092 (China); Zhao Guohua, E-mail: g.zhao@tongji.edu.cn [Department of Chemistry, Tongji University, Shanghai, 200092 (China); Wu Meifen; Lei Yanzhu; Geng Rong [Department of Chemistry, Tongji University, Shanghai, 200092 (China)

    2009-08-30

    In this paper the electrochemical degradation of chlorobenzene (CB) was investigated on boron-doped diamond (BDD) and platinum (Pt) anodes, and the degradation kinetics on these two electrodes was compared. Compared with the total mineralization with a total organic carbon (TOC) removal of 85.2% in 6 h on Pt electrode, the TOC removal reached 94.3% on BDD electrode under the same operate condition. Accordingly, the mineralization current efficiency (MCE) during the mineralization on BDD electrode was higher than that on the Pt electrode. Besides TOC, the conversion of CB, the productions and decay of intermediates were also monitored. Kinetic study indicated that the decay of CB on BDD and Pt electrodes were both pseudo-first-order reactions, and the reaction rate constant (k{sub s}) on BDD electrode was higher than that on Pt electrode. The different reaction mechanisms on the two electrodes were investigated by the variation of intermediates concentrations. Two different reaction pathways for the degradation of CB on BDD electrode and Pt electrode involving all these intermediates were proposed.

  19. Electrochemical degradation of chlorobenzene on boron-doped diamond and platinum electrodes.

    Science.gov (United States)

    Liu, Lei; Zhao, Guohua; Wu, Meifen; Lei, Yanzhu; Geng, Rong

    2009-08-30

    In this paper the electrochemical degradation of chlorobenzene (CB) was investigated on boron-doped diamond (BDD) and platinum (Pt) anodes, and the degradation kinetics on these two electrodes was compared. Compared with the total mineralization with a total organic carbon (TOC) removal of 85.2% in 6h on Pt electrode, the TOC removal reached 94.3% on BDD electrode under the same operate condition. Accordingly, the mineralization current efficiency (MCE) during the mineralization on BDD electrode was higher than that on the Pt electrode. Besides TOC, the conversion of CB, the productions and decay of intermediates were also monitored. Kinetic study indicated that the decay of CB on BDD and Pt electrodes were both pseudo-first-order reactions, and the reaction rate constant (k(s)) on BDD electrode was higher than that on Pt electrode. The different reaction mechanisms on the two electrodes were investigated by the variation of intermediates concentrations. Two different reaction pathways for the degradation of CB on BDD electrode and Pt electrode involving all these intermediates were proposed. PMID:19264395

  20. Simultaneous Chronoamperometric Sensing of Ascorbic Acid and Acetaminophen at a Boron-Doped Diamond Electrode

    Directory of Open Access Journals (Sweden)

    Ciprian Radovan

    2008-06-01

    Full Text Available Cyclic voltammetry (CV and chronoamperometry (CA have been used to sense and determine simultaneously L-ascorbic acid (AA and acetaminophen (AC at a boron-doped diamond electrode (BDDE in a Britton-Robinson buffer solution. The calibration plots of anodic current peak versus concentration obtained from CV and CA data for both investigated compounds in single and di-component solutions over the concentration range 0.01 mM – 0.1 mM proved to be linear, with very good correlation parameters. Sensitivity values and RSD of 2-3% were obtained for various situations, involving both individual and simultaneous presence of AA and AC. The chronoamperometric technique associated with standard addition in sequential one step and/or two successive and continuous chronoamperograms at two characteristic potential levels represented a feasible option for the simultaneous determination of AA and AC in real sample systems such as pharmaceutical formulations. The average values indicated by the supplier were confirmed to a very close approximation from chronoamperomgrams by using several additions with the application of suitable current correction factors.

  1. Continuous and selective measurement of oxytocin and vasopressin using boron-doped diamond electrodes

    Science.gov (United States)

    Asai, Kai; Ivandini, Tribidasari A.; Einaga, Yasuaki

    2016-09-01

    The electrochemical detection of oxytocin using boron-doped diamond (BDD) electrodes was studied. Cyclic voltammetry of oxytocin in a phosphate buffer solution exhibits an oxidation peak at +0.7 V (vs. Ag/AgCl), which is attributable to oxidation of the phenolic group in the tyrosyl moiety. Furthermore, the linearity of the current peaks obtained in flow injection analysis (FIA) using BDD microelectrodes over the oxytocin concentration range from 0.1 to 10.0 μM with a detection limit of 50 nM (S/N = 3) was high (R2 = 0.995). Although the voltammograms of oxytocin and vasopressin observed with an as-deposited BDD electrode, as well as with a cathodically-reduced BDD electrode, were similar, a clear distinction was observed with anodically-oxidized BDD electrodes due to the attractive interaction between vasopressin and the oxidized BDD surface. By means of this distinction, selective measurements using chronoamperometry combined with flow injection analysis at an optimized potential were demonstrated, indicating the possibility of making selective in situ or in vivo measurements of oxytocin.

  2. Boron-doped diamond microelectrodes for use in capillary electrophoresis with electrochemical detection.

    Science.gov (United States)

    Cvacka, Josef; Quaiserová, Veronika; Park, JinWoo; Show, Yoshiyuki; Muck, Alexander; Swain, Greg M

    2003-06-01

    The fabrication and characterization of boron-doped diamond microelectrodes for use in electrochemical detection coupled with capillary electrophoresis (CE-EC) is discussed. The microelectrodes were prepared by coating thin films of polycrystalline diamond on electrochemically sharpened platinum wires (76-, 25-, and 10-microm diameter), using microwave-assisted chemical vapor deposition (CVD). The diamond-coated wires were attached to copper wires (current collectors), and several methods were explored to insulate the cylindrical portion of the electrode: nail polish, epoxy, polyimide, and polypropylene coatings. The microelectrodes were characterized by scanning electron microscopy, Raman spectroscopy, and cyclic voltammetry. They exhibited low and stable background currents and sigmoidally shaped voltammetric curves for Ru(NH3)6(3+/2+) and Fe(CN)6(3-/4-) at low scan rates. The microelectrodes formed with the large diameter Pt and sealed in polypropylene pipet tips were employed for end-column detection in CE. Evaluation of the CE-EC system and the electrode performance were accomplished using a 10 mM phosphate buffer, pH 6.0, run buffer, and a 30-cm-long fused-silica capillary (75-microm i.d.) with dopamine, catechol, and ascorbic acid serving as test analytes. The background current (approximately 100 pA) and noise (approximately 3 pA) were measured at different detection potentials and found to be very stable with time. Reproducible separation (elution time) and detection (peak current or area) of dopamine, catechol, and ascorbic acid were observed with response precisions of 4.1% or less. Calibration curves constructed from the peak area were linear over 4 orders of magnitude, up to a concentration between 0.1 and 1 mM. Mass limits of detection for dopamine and catechol were 1.7 and 2.6 fmol, respectively (S/N = 3). The separation efficiency was approximately 33,000, 56,000, and 98,000 plates/m for dopamine, catechol, and ascorbic acid, respectively. In

  3. Electrocatalytic and photocatalytic activity of Pt-TiO2 films on boron-doped diamond substrate

    Science.gov (United States)

    Spătaru, Tanţa; Marcu, Maria; Spătaru, Nicolae

    2013-03-01

    In the present work boron-doped diamond (BDD) polycrystalline films were used as support for direct anodic deposition of hydrous titanium oxide, and continuous TiO2 coatings were obtained by appropriately adjusting the deposition charge. The photoelectrochemical activity of the TiO2/BDD electrodes was investigated and it was found that, in terms of charge carriers separation efficiency, conductive diamond is a much better support for TiO2, compared to traditional carbonaceous materials such as glassy carbon. Further electrochemical deposition of platinum particles on the oxide-coated conductive diamond enabled the formation of a composite with enhanced electrochemically active surface area. The electrocatalytic and photocatalytic properties of the Pt/TiO2/BDD electrodes thus obtained were also scrutinized and it appeared that these hybrid systems also exhibit promising features for methanol anodic oxidation.

  4. Fano interference of the Raman phonon in heavily boron-doped diamond films grown by chemical vapor deposition

    International Nuclear Information System (INIS)

    A series of boron-doped polycrystalline diamond films grown by direct current and microwave plasma deposition was studied with Raman and infrared (IR) absorption spectroscopy. A Fano line shape is observed in the Raman spectra for films with a boron concentration in a narrow range near 1021 cm-3. The appearance of the Fano line shape is correlated with the disappearance of discrete electronic transitions of the boron acceptor observed in the IR spectrum and the shift of the broadened peak to lower energy. The Fano interaction is attributed to a quantum mechanical interference between the Raman phonon (0.165 eV) and transitions from the broadened impurity band to continuum states composed of excited acceptor and valence band states

  5. Study of Electrochemical Degradation of Bromophenol Blue at Boron-doped Diamond Electrode by Using Factorial Design Analysis

    Directory of Open Access Journals (Sweden)

    Rong Fei

    2015-01-01

    Full Text Available As an ideal anode material, Boron-doped diamond (BDD has been widely applied in electro-chemical oxidation of various organic pollutants, for its unique physical and chemical properties. In this paper, the authors studied the degradation of bromophenol blue through the electrochemical anodic oxidation by using the boron-doped BDD as the anode. The effect of statistically important operating parameters on treatment per-formance, such as treatment time, flow rate, applied current and concentration of supporting electrolyte, was evaluated by employing a factorial design analysis in terms of color removal and COD removal amount. As a result, the BDD technology was approved to be highly effective in treating bromophenol blue. Moreover, the results revealed the applicability and potential of factorial design analysis in operating parameters optimization and practical engineering application of BDD technology.

  6. Evaluation of freestanding boron-doped diamond grown by chemical vapour deposition as substrates for vertical power electronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Issaoui, R.; Achard, J.; Tallaire, A.; Silva, F.; Gicquel, A. [LSPM-CNRS (formerly LIMHP), Universite Paris 13, 99, Avenue Jean-Baptiste Clement, 93430 Villetaneuse (France); Bisaro, R.; Servet, B.; Garry, G. [Thales Research and Technology France, Campus de Polytechnique, 1 Avenue Augustin Fresnel, F-91767 Palaiseau Cedex (France); Barjon, J. [GEMaC-CNRS, Universite de Versailles Saint Quentin Batiment Fermat, 45 Avenue des Etats-Unis, 78035 Versailles Cedex (France)

    2012-03-19

    In this study, 4 x 4 mm{sup 2} freestanding boron-doped diamond single crystals with thickness up to 260 {mu}m have been fabricated by plasma assisted chemical vapour deposition. The boron concentrations measured by secondary ion mass spectroscopy were 10{sup 18} to 10{sup 20} cm{sup -3} which is in a good agreement with the values calculated from Fourier transform infrared spectroscopy analysis, thus indicating that almost all incorporated boron is electrically active. The dependence of lattice parameters and crystal mosaicity on boron concentrations have also been extracted from high resolution x-ray diffraction experiments on (004) planes. The widths of x-ray rocking curves have globally shown the high quality of the material despite a substantial broadening of the peak, indicating a decrease of structural quality with increasing boron doping levels. Finally, the suitability of these crystals for the development of vertical power electronic devices has been confirmed by four-point probe measurements from which electrical resistivities as low as 0.26 {Omega} cm have been obtained.

  7. Evaluation of freestanding boron-doped diamond grown by chemical vapour deposition as substrates for vertical power electronic devices

    International Nuclear Information System (INIS)

    In this study, 4 x 4 mm2 freestanding boron-doped diamond single crystals with thickness up to 260 μm have been fabricated by plasma assisted chemical vapour deposition. The boron concentrations measured by secondary ion mass spectroscopy were 1018 to 1020 cm-3 which is in a good agreement with the values calculated from Fourier transform infrared spectroscopy analysis, thus indicating that almost all incorporated boron is electrically active. The dependence of lattice parameters and crystal mosaicity on boron concentrations have also been extracted from high resolution x-ray diffraction experiments on (004) planes. The widths of x-ray rocking curves have globally shown the high quality of the material despite a substantial broadening of the peak, indicating a decrease of structural quality with increasing boron doping levels. Finally, the suitability of these crystals for the development of vertical power electronic devices has been confirmed by four-point probe measurements from which electrical resistivities as low as 0.26 Ω cm have been obtained.

  8. Evaluation of freestanding boron-doped diamond grown by chemical vapour deposition as substrates for vertical power electronic devices

    Science.gov (United States)

    Issaoui, R.; Achard, J.; Tallaire, A.; Silva, F.; Gicquel, A.; Bisaro, R.; Servet, B.; Garry, G.; Barjon, J.

    2012-03-01

    In this study, 4 × 4 mm2 freestanding boron-doped diamond single crystals with thickness up to 260 μm have been fabricated by plasma assisted chemical vapour deposition. The boron concentrations measured by secondary ion mass spectroscopy were 1018 to 1020 cm-3 which is in a good agreement with the values calculated from Fourier transform infrared spectroscopy analysis, thus indicating that almost all incorporated boron is electrically active. The dependence of lattice parameters and crystal mosaicity on boron concentrations have also been extracted from high resolution x-ray diffraction experiments on (004) planes. The widths of x-ray rocking curves have globally shown the high quality of the material despite a substantial broadening of the peak, indicating a decrease of structural quality with increasing boron doping levels. Finally, the suitability of these crystals for the development of vertical power electronic devices has been confirmed by four-point probe measurements from which electrical resistivities as low as 0.26 Ω cm have been obtained.

  9. Characterization of Optical and Electrical Properties of Transparent Conductive Boron-Doped Diamond thin Films Grown on Fused Silica

    Directory of Open Access Journals (Sweden)

    Bogdanowicz Robert

    2014-12-01

    Full Text Available Abstract A conductive boron-doped diamond (BDD grown on a fused silica/quartz has been investigated. Diamond thin films were deposited by the microwave plasma enhanced chemical vapor deposition (MW PECVD. The main parameters of the BDD synthesis, i.e. the methane admixture and the substrate temperature were investigated in detail. Preliminary studies of optical properties were performed to qualify an optimal CVD synthesis and film parameters for optical sensing applications. The SEM micro-images showed the homogenous, continuous and polycrystalline surface morphology; the mean grain size was within the range of 100-250 nm. The fabricated conductive boron-doped diamond thin films displayed the resistivity below 500 mOhm cm-1 and the transmittance over 50% in the VIS-NIR wavelength range. The studies of optical constants were performed using the spectroscopic ellipsometry for the wavelength range between 260 and 820 nm. A detailed error analysis of the ellipsometric system and optical modelling estimation has been provided. The refractive index values at the 550 nm wavelength were high and varied between 2.24 and 2.35 depending on the percentage content of methane and the temperature of deposition.

  10. Electronic structure of boron-doped diamond with B–H complex and B pair

    Directory of Open Access Journals (Sweden)

    Tamio Oguchi

    2008-01-01

    Full Text Available The electronic structure of boron–hydrogen complex and boron pair in diamond are studied by first-principles density-functional calculations with supercell models. The electronic structure calculated for the B–H complexes with C2v or C3v symmetry and the nearest-neighbor B pair is used to interpret recent experimental results such as B 1s x-ray photoemission spectroscopy, 11B nuclear quadruple resonance and B K-edge x-ray absorption spectroscopy, which cannot be explained solely by the isolated substitutional boron.

  11. Bioelectrochemical degradation of urea at platinized boron doped diamond electrodes for bioregenerative applications

    Science.gov (United States)

    Nicolau, Eduardo; Gonzalez, Ileana; Nicolau, Eduardo; Cabrera, Carlos R.

    The recovery of potable water from space mission wastewater is critical for the life support and environmental health of crew members in long-term missions. NASA estimates reveal that at manned space missions 0.06 kg/person·day of urine is produced, with urea and various salts as its main components. Current spacecraft water reclamation strategies include the utilization of not only multifiltration systems (MF) and reverse osmosis (RO), but also biological components to deal with crew urine streams. In this research we explore the utilization of urease (EC 3.5.1.5) to convert urea directly to nitrogen by the in-situ utilization of the reaction products, to increase the amount of clean water in future space expeditions. First of all, platinum was electrodeposited on boron doped diamond electrodes by cycling the potential between -0.2 V and 1.0 V in metal/0.5 M H2SO4 solution. SEM images of the electrodes showed a distribution of platinum nanoparticles ranging between 50 nm and 300 nm. The biochemical reaction of urease in nature produces ammonia and carbon dioxide from urea. Based on this, Cyclic Voltammetry experiments of an ammonium acetate solution at pH 10 were performed showing an anodic peak at -0.3 V vs. Ag/AgCl due to the ammonia oxidation. Then, a urease solution (Jack Bean) was poured into the electrochemical cell and subsequent additions of urea were performed with the potential held at -0.3 V in order to promote ammonia oxidation. Chronoamperometry data shows that with more than five urea additions the enzyme still responding by producing ammonia, which is being subsequently oxidized at the electrode surface and producing molecular nitrogen. This research has tremendous applications for future long-term space missions since the reaction byproducts could be used for a biomass subsystem (in-situ resource recovery), while generating electricity from the same process.

  12. Decomposition of various endocrine-disrupting chemicals at boron-doped diamond electrode

    Energy Technology Data Exchange (ETDEWEB)

    Yoshihara, S. [Department of Energy and Environmental Science, Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585 (Japan)], E-mail: sachioy@cc.utsunomiya-u.ac.jp; Murugananthan, M. [Department of Energy and Environmental Science, Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585 (Japan)

    2009-02-28

    Anodic decomposition of endocrine disrupting chemicals (EDCs) namely, 17{beta}-estradiol (E2) and Bisphenol A (BPA) at boron-doped diamond (BDD) has been studied with a working solution volume of 250 ml under galvanostatic mode. Cyclic voltammetric experiments were performed to examine the redox response of E2 and BPA as a function of cycle number. Kinetic analysis suggests that electro-oxidation reaction of EDCs undergo the control of applied current density (I{sub appl}). The mineralization behavior of EDCs was investigated at BDD anode monitoring the total organic carbon (TOC) value at three different I{sub appl}. Electrolysis at high anodic potential causes complex oxidation of EDCs that lead to form the final sole product as CO{sub 2}. From these TOC results, the mineralization current efficiency was evaluated and discussed. In order to examine the effect of electrolyte variables on EDCs, BPA compound was taken and undergone the supporting medium and pH variation experiments. Considering global oxidation process, the effect of supporting medium (Na{sub 2}SO{sub 4}, NaNO{sub 3}, and NaCl) has been discussed in terms of electro-generated inorganic oxidants such as S{sub 2}O{sub 8}{sup 2-}, H{sub 2}O{sub 2} and ClO{sup -}. The better performance of BDD anode was proved on a comparative study with Pt and glassy carbon under similar experimental conditions. A possible reaction mechanism for BPA degradation involving three main aromatic intermediates, identified by GC-MS analysis, was proposed.

  13. Mechanistic studies on boron-doped diamond: Oxidation of small organic molecules

    International Nuclear Information System (INIS)

    The electro-oxidation of ethanol, acetone, i-propanol, its fluorinated analogue hexafluoroisopropanol (HFiP) and cyclohexane in 1 M HClO4 was studied on a boron doped diamond (BDD) electrode by on-line differential electrochemical mass spectrometry (DEMS), using a dual thin layer cell. One can distinguish two oxidation pathways: at potentials below 2.5 V a direct electron transfer to the BDD takes place, while at potentials above 2.5 V OH radicals are produced and scavenged by the reactants. As a consequence, the oxygen evolution reaction is at least partially suppressed. The direct electron transfer to the electrode is observed for i-propanol, ethanol and cyclohexane. For acetone and HFiP, only the second, indirect, pathway with the participation of OH radicals is effective. For all the reactants except HFiP CO2 formation was observed generally at 2.5 V or higher, the potential for the oxygen evolution reaction (OER) in the pure supporting electrolyte. Hence OH radicals are instrumental in the cleavage of C-C bonds. For HFiP, the cyclic voltammograms of the supporting electrolyte with and without the reactant are identical. This indicates that the oxidation of HFiP is initiated by OH radicals followed by a further electron transfer to the electrode, similarly to the oxidation of CO (I. Kisacik, A. Stefanova, S. Ernst and H. Baltruschat, PCCP, 15 (2013) 4616). For both pathways, the reactivity follows the same trend as the homogeneous hydrogen abstraction reaction rates with OH radicals. The intermediate radicals formed in the reaction with the electro-generated OH radicals can react with oxygen present in the solution

  14. Feedback-amplified electrochemical dual-plate boron-doped diamond microtrench detector for flow injection analysis

    Science.gov (United States)

    Lewis, Grace E M; Gross, Andrew J; Kasprzyk-Hordern, Barbara; Lubben, Anneke T; Marken, Frank

    2015-01-01

    An electrochemical flow cell with a boron-doped diamond dual-plate microtrench electrode has been developed and demonstrated for hydroquinone flow injection electroanalysis in phosphate buffer pH 7. Using the electrochemical generator-collector feedback detector improves the sensitivity by one order of magnitude (when compared to a single working electrode detector). The diffusion process is switched from an analyte consuming “external” process to an analyte regenerating “internal” process with benefits in selectivity and sensitivity. PMID:25735831

  15. Biophotonic low-coherence sensors with boron-doped diamond thin layer

    Science.gov (United States)

    Milewska, D.; Karpienko, K.; Sobaszek, M.; Jedrzejewska-Szczerska, M.

    2016-03-01

    Low-coherence sensors using Fabry-Perot interferometers are finding new applications in biophotonic sensing, especially due to the rapid technological advances in the development of new materials. In this paper we discuss the possibility of using boron-doped nanodiamond layers to protect mirror in a Fabry-Perot interferometer. A low-coherence sensor using Fabry-Perot interferometer with a boron-doped nanodiamond (B-NCD) thin protective layer has been developed. B-NCD layers with different boron doping level were investigated. The boron level, expressed as the boron to carbon (/[C]) ratio in the gas phase, was: 0, 2000, 5000 or 10000 ppm. B-NCD layers were grown by chemical vapor deposition (CVD). The sensing Fabry-Perot interferometer, working in the reflective mode, was connected to the source and to the optical processor by single-mode fibers. Superluminescent diodes with Gaussian spectral density were used as sources, while an optical spectrum analyzer was used as an optical processor. The design of the sensing interferometer was optimized to attain the maximum interference contrast. The experiment has shown that B-NCD thin layers can be successfully used in biophotonic sensors.

  16. Electrochemical Detection of Clenbuterol in Pig Liver at Pyrrole-DNA Modified Boron-doped Diamond Electrode

    Institute of Scientific and Technical Information of China (English)

    WU Jing; LI Xiao-li; WU Xu-mei; HUAN Shuang-yan; SHEN Guo-li; YU Ru-qin

    2005-01-01

    The direct detection of clenbuterol(CL) in pig liver without any extraction separation at a pyrrole-DNA modified boron-doped diamond(BDD) electrode is reported. The pyrrole-DNA modified BDD electrode has a strong electrocatalytic effect on the redox reaction of CL. One oxidization and two reduction peaks of CL appear at 340.2, 299.8 and 166.6 mV(versus SCE), respectively. The pyrrole polymer alone cannot electrocatalyze the above reaction at a BDD electrode; the electrocatalytic effect of a BDD electrode modified with DNA membrane is unsufficient for the analytical detection of CL; the replacement of boron-doped diamond by glass carbon makes the electrocatalytic reaction impossible; the redox process is pH dependent. The influences of various experimental parameters on the pyrrole-DNA modified BDD electrode were investigated. A sensitive cyclic voltammetric response for CL was obtained in a linear range from 3.4×10-6 to 5×10-4 mol/L with a detection limit of 8.5×10-7 mol/L. A mean recovery of 102.7% of CL in the pig liver sample solution and a reproducibility of 3.2% were obtained.

  17. Effect of Polishing on the Friction Behaviors and Cutting Performance of Boron-Doped Diamond Films on WC-Co Inserts

    Science.gov (United States)

    Wang, Liang; Shen, Bin; Sun, Fanghong; Zhang, Zhiming

    2014-04-01

    Boron doped (B-doped) diamond films are deposited onto WC-Co inserts by HFCVD with the mixture of acetone, trimethyl borate (C3H9BO3) and H2. The as-deposited B-doped diamond films are characterized with scanning electron microscope (SEM), X-ray diffraction (XRD) spectroscopy, Raman spectroscopy, 3D surface topography based on white-light interferometry and Rockwell hardness tester. The effects of mechanical polishing on the friction behavior and cutting performance of B-doped diamond are evaluated by ball-on-plate type reciprocating tribometer and turning of aluminum alloy 7075 materials, respectively. For comparison, the same tests are also conducted for the bare WC-Co inserts with smooth surface. Friction tests suggest that the unpolished and polished B-doped diamond films possess relatively low fluctuation of friction coefficient than as-received bare WC-Co samples. The average stable friction coefficient for B-doped diamond films decreases apparently after mechanical polishing. The values for WC-Co sample, unpolished and polished B-doped diamond films are approximately 0.38, 0.25 and 0.11, respectively. The cutting results demonstrate that the low friction coefficient and high adhesive strength of B-doped diamond films play an essential role in the cutting performance enhancement of the WC-Co inserts. However, the mechanical polishing process may lower the adhesive strength of B-doped diamond films. Consequently, the polished B-doped diamond coated inserts show premature wear in the machining of adhesive aluminum alloy materials.

  18. Influences of H+ Implantation on the Boron-Doped Synthesized by Chemical Vapor Deposition Diamond Films

    Institute of Scientific and Technical Information of China (English)

    WANG Shuang-Bao

    2000-01-01

    Diamond films (DF) were preliminarily B doped in situ during chemical vapor deposition. Subsequently, the films were implanted with 120keV H+ to dose of 5 × 1014 ~ 5 × 1016cm-2. After the implantation, the B doped DF become insulating and Raman measurements indicate that the implantation has amorphous carbon and graphite etched. It is known that the formation of H-B pairs plays an important pole in property changes. However, for larger dose cases, the electrical resistance of DF is influenced by radiation damage and/or non-diamond phases. In addition to them, annealing makes the specimens conducting again. This phenomenon maybe has potential for application in designing DF device.

  19. Monitoring the evolution of boron doped porous diamond electrode on flexible retinal implant by OCT and in vivo impedance spectroscopy.

    Science.gov (United States)

    Hébert, Clément; Cottance, Myline; Degardin, Julie; Scorsone, Emmanuel; Rousseau, Lionel; Lissorgues, Gaelle; Bergonzo, Philippe; Picaud, Serge

    2016-12-01

    Nanocrystalline Boron doped Diamond proved to be a very attractive material for neural interfacing, especially with the retina, where reduce glia growth is observed with respect to other materials, thus facilitating neuro-stimulation over long terms. In the present study, we integrated diamond microelectrodes on a polyimide substrate and investigated their performances for the development of neural prosthesis. A full description of the microfabrication of the implants is provided and their functionalities are assessed using cyclic voltammetry and electrochemical impedance spectroscopy. A porous structure of the electrode surface was thus revealed and showed promising properties for neural recording or stimulation. Using the flexible implant, we showed that is possible to follow in vivo the evolution of the electric contact between the diamond electrodes and the retina over 4months by using electrochemical impedance spectroscopy. The position of the implant was also monitored by optical coherence tomography to corroborate the information given by the impedance measurements. The results suggest that diamond microelectrodes are very good candidates for retinal prosthesis. PMID:27612691

  20. Size-Dependent Electrocatalytic Activity of Gold Nanoparticles on HOPG and Highly Boron-Doped Diamond Surfaces

    Directory of Open Access Journals (Sweden)

    Tine Brülle

    2011-12-01

    Full Text Available Gold nanoparticles were prepared by electrochemical deposition on highly oriented pyrolytic graphite (HOPG and boron-doped, epitaxial 100-oriented diamond layers. Using a potentiostatic double pulse technique, the average particle size was varied in the range from 5 nm to 30 nm in the case of HOPG as a support and between < 1 nm and 15 nm on diamond surfaces, while keeping the particle density constant. The distribution of particle sizes was very narrow, with standard deviations of around 20% on HOPG and around 30% on diamond. The electrocatalytic activity towards hydrogen evolution and oxygen reduction of these carbon supported gold nanoparticles in dependence of the particle sizes was investigated using cyclic voltammetry. For oxygen reduction the current density normalized to the gold surface (specific current density increased for decreasing particle size. In contrast, the specific current density of hydrogen evolution showed no dependence on particle size. For both reactions, no effect of the different carbon supports on electrocatalytic activity was observed.

  1. Voltammetric and electrochemical impedance spectroscopy characterization of a cathodic and anodic pre-treated boron doped diamond electrode

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, S. Carlos B. [Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Universidade de Coimbra, 3004-535 Coimbra (Portugal); Oliveira-Brett, Ana Maria, E-mail: brett@ci.uc.p [Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Universidade de Coimbra, 3004-535 Coimbra (Portugal)

    2010-06-01

    The effect of boron doped diamond (BDD) surface termination, immediately after cathodic and anodic electrochemical pre-treatments, on the electrochemical response of a BDD electrode in aqueous media and the influence of the different supporting electrolytes utilized in these pre-treatments on the final surface termination was investigated with [Fe(CN){sub 6}]{sup 4-/3-}, as redox probe, by cyclic and differential pulse voltammetry and electrochemical impedance spectroscopy. The cyclic voltammetry results indicate that the electrochemical behavior for the redox couple [Fe(CN){sub 6}]{sup 4-/3-} is very dependent on the state of the BDD surface, and a reversible response was observed after the cathodic electrochemical pre-treatment, whereas a quasi-reversible response occurred after anodic electrochemical pre-treatment. Differential pulse voltammetry in acetate buffer also showed that the potential window is very much influenced by the electrochemical pre-treatment of the BDD surface. Electroactivity of non-diamond carbon surface species (sp{sup 2} inclusions) incorporated into the diamond structure was observed after cathodic and anodic pre-treatments. Electrochemical impedance spectroscopy confirmed the cyclic voltammetry results and indicates that the BDD surface resistance and capacitance vary significantly with the electrolyte and with the electrochemical pre-treatment, caused by different surface terminations of the BDD electrode surface.

  2. Fluorine and boron co-doped diamond-like carbon films deposited by pulsed glow discharge plasma immersion ion processing

    CERN Document Server

    He, X M; Peters, A M; Taylor, B; Nastasi, M

    2002-01-01

    Fluorine (F) and boron (B) co-doped diamond-like carbon (FB-DLC) films were prepared on different substrates by the plasma immersion ion processing (PIIP) technique. A pulse glow discharge plasma was used for the PIIP deposition and was produced at a pressure of 1.33 Pa from acetylene (C sub 2 H sub 2), diborane (B sub 2 H sub 6), and hexafluoroethane (C sub 2 F sub 6) gas. Films of FB-DLC were deposited with different chemical compositions by varying the flow ratios of the C sub 2 H sub 2 , B sub 2 H sub 6 , and C sub 2 F sub 6 source gases. The incorporation of B sub 2 H sub 6 and C sub 2 F sub 6 into PIIP deposited DLC resulted in the formation of F-C and B-C hybridized bonding structures. The levels of the F and B concentrations effected the chemical bonding and the physical properties as was evident from the changes observed in density, hardness, stress, friction coefficient, and contact angle of water on films. Compared to B-doped or F-doped DLC films, the F and B co-doping of DLC during PIIP deposition...

  3. Sensitive voltammetric method for rapid determination of pyridine herbicide triclopyr on bare boron-doped diamond electrode

    International Nuclear Information System (INIS)

    Voltammetric method for the determination of a pyridine herbicide triclopyr (3,5,6-trichloro-2-pyridyloxyacetic acid) is presented for the first time using bare boron-doped diamond electrode. Triclopyr provides one well-developed, pH-independent oxidation signal at ca. +1.9 V (vs. Ag∣AgCl∣KCl (sat.)) contrary to structurally related clopyralid, which is not oxidizable at the working electrode. Britton–Robinson buffer (pH 2.0) was chosen as optimal electrolyte for determination of triclopyr using square wave and differential pulse voltammetry. The latter method provided slightly better detection limit of 0.82 μmol L−1 and linearity in the concentration range 1.0–108.8 μmol L−1. Applicability of the proposed method was verified by analysis of pesticide preparation, spiked water and urine with excellent results

  4. Development of Sensitive Analytical Approach for the Quantification of α-Lipoic Acid Using Boron Doped Diamond Electrode.

    Science.gov (United States)

    Stankovic, Dalibor M; Mehmeti, Eda; Kalcher, Kurt

    2016-01-01

    A boron doped diamond (BDD) electrode was investigated for use as an electrochemical sensor for α-lipoic acid (LA) using amperometric and differential pulse voltammetric detection. LA displays a well expressed oxidation peak at +0.9 V vs. Ag/AgCl in solutions with a pH value of 3. It was found that signals obtained are linearly related to the concentration range from 0.3 to 105 μM with detection limit of 0.088 μM. Interferences by common compounds such as ascorbic acid, uric acid and dopamine were tested and the method was successfully applied to the determination of LA in human body fluids where it gave recoveries in the range from 95 to 97%. PMID:27506710

  5. Preparation of grain size controlled boron-doped diamond thin films and their applications in selective detection of glucose in basic solutions

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Boron-doped diamond (BDD) thin films with different crystal grain sizes were prepared by controlling the reacting gas pressure using hot filament chemical vapor deposition (HFCVD).The morphologies and structures of the prepared diamond thin films were characterized by scanning electron microscopy (SEM) and Raman spectroscopy.The electrochemical responses of K4Fe(CN)6 on different BDD electrodes were investigated.The results suggested that electron transfer was faster at the boron-doped nanocrystalline diamond (BDND) thin film electrodes in comparison with that at other BDD thin film electrodes.The prepared BDD thin film electrodes without any modification were used to directly detect glucose in the basic solution.The results showed that the as-prepared BDD thin film electrodes exhibited good selectivity for detecting glucose in the presence of ascorbic acid (AA) and uric acid (UA).The higher sensitivity was observed on the BDND thin film grown on the boron-doped microcrystalline diamond (BDMD) thin film surface,and the linear response range,sensitivity and the low detection limit were 0.25–10 mM,189.1 μA mmol-1 cm-2 and 25 μM (S/N=3) for glucose in the presence of AA and UA,respectively.

  6. Electrochemical oxidation using a boron doped diamond electrode as a water treatment process- removal of residual micropollutants and inac-tivation of microorganisms

    OpenAIRE

    Rajab, Mohamad Dib

    2015-01-01

    A boron doped diamond electrode was tested for the removal of micropollutants and inactivation of microorganisms. The results showed that higher current densities accelerated the degradation process, whereas an increase in water complexity decelerated it. A current density between 100-200 mA cm-2 would completely remove micropollutants and limit the formation of inorganic by-products. A synergic effect of reactive oxygen and chlorine species assured the disinfection capability of the electrod...

  7. A comparative study of electrochemical oxidation of methidation organophosphorous pesticide on SnO2 and boron-doped diamond anodes

    OpenAIRE

    Hachami, Fatima; Errami, Mohamed; Bazzi, Lahcen; Hilali, Mustapha; Salghi, Rachid; Jodeh, Shehdeh; Hammouti, Belkheir; Hamed, Othman A.

    2015-01-01

    Background Electrochemical oxidation considered to be among the best methods in waste water desalination and removing toxic metals and organic pesticides from wastewater like Methidathion. The objective of this work is to study the electrochemical oxidation of aqueous wastes containing Methidathion using boron doped diamond thin-film electrodes and SnO2, and to determine the calculated partial charge and frontier electron density parameters. Results Electrolysis parameters such as current den...

  8. Cathodic and anodic pre-treated boron doped diamond with different sp2 content: Morphological, structural, and impedance spectroscopy characterizations

    Science.gov (United States)

    Baldan, M. R.; Azevedo, A. F.; Couto, A. B.; Ferreira, N. G.

    2013-12-01

    In this work, the influence of cathodic (Red) and anodic (Ox) pre-treatment on boron doped diamond (BDD) films grown with different sp2/sp3 ratios was systematically studied. The sp2/sp3 ratios were controlled by the addition of CH4 of 1,3,5 and 7 sccm in the gas inlet during the growth process. The electrodes were treated in 0.5 mol L-1 H2SO4 at -3 and 3 V vs Ag/AgCl, respectively, for 30 min. The electrochemical response of BDD films was investigated using electrochemical impedance spectroscopy (EIS) and Mott-Schottky Plot (MSP) measurements. Four film sample sets were produced in a hot filament chemical vapor deposition reactor. During the growth process, an additional H2 line passing through a bubbler containing the B2O3 dissolved in methanol was used to carry the boron. The scanning electron microscopy morphology showed well faced films with a small decrease in their grain size as the CH4 concentration increased. The Raman spectra depicted a pronounced sp2 band, mainly for films with 5 and 7 sccm of CH4. MSP showed a decrease in the acceptor concentration as the CH4 increased indicating the CH4 influence on the doping process for Red-BDD and Ox-BDD samples. Nonetheless, an apparent increase in the acceptor concentrations for both Ox-BDD samples was observed compared to that for Red-BDD samples, mainly attributed to the surface conductive layer (SCL) formation after this strong oxidation process. The EIS Nyquist plots for Red-BDD showed a capacitance increase for the films with higher sp2 content (5 and 7 sccm). On the other hand, the Nyquist plots for Ox-BDD can be described as semicircles near the origin, at high frequencies, where their charge transfer resistance strongly varied with the sp2 increase in such films.

  9. Studies on distribution of element contents in transient layer at interface between boron-doped diamond film electrode and tantalum substrate

    International Nuclear Information System (INIS)

    The boron-doped diamond film (BDD) grown on tantalum (Ta) substrate as an electrode (BDD/Ta) was prepared by hot filament chemical vapor deposition method. The experimental results demonstrated that our BDD/Ta had high current efficiency, strong ability to degrade wastewater, good corrosion stability and long lifetime. These excellent characteristics of BDD/Ta have been explained in terms of Rutherford backscattering (RBS) experiments. RBS investigation revealed that the continuous transient layer at the interface between boron-doped diamond film and Ta-substrate was formed and the microstructure of the continuous transient layer given by the continuous distribution of all element contents at the interface was obtained. The thicknesses of boron-doped diamond film and the continuous transient layer were about equal to 8000 x 1015 atoms/cm2 and 5800 x 1015 atoms/cm2, respectively. The formation of the continuous transient layer at the interface can eliminate the mismatch of thermal expansion coefficients (TEC) at the interface and only lead to the slow change of TEC because of the continuous distribution of element contents of the film and substrate in the transient layer at the interface. Thus, there is no residual stress to concentrate on the interface and the stress-corrosion delamination of the film disappears. Therefore, the corrosion stability and lifetime of BDD/Ta increase and last well, that have been verified by X-ray diffraction (XRD) experiments.

  10. Studies on distribution of element contents in transient layer at interface between boron-doped diamond film electrode and tantalum substrate

    Energy Technology Data Exchange (ETDEWEB)

    Liang Jiachang, E-mail: jcliang@cauc.edu.cn [College of Science, Civil Aviation University of China, Jin Bei highway No.2898, Southern campus of Civil Aviation, Tianjin 300300 (China); Gao Chengyao [Chinese People' s Armed Police Forces Academy, Langfang, Hebei 065000 (China); Zhang Liping [College of Science, Civil Aviation University of China, Jin Bei highway No.2898, Southern campus of Civil Aviation, Tianjin 300300 (China); Jiang Lihui [Tianjin Key Laboratory for Advanced Signal Processing, Civil Aviation University of China, Tianjin 300300 (China); Yang Zhengquan; Wang Zhiping; Ji Chaohui [College of Science, Civil Aviation University of China, Jin Bei highway No.2898, Southern campus of Civil Aviation, Tianjin 300300 (China); Le Xiaoyun; Rong Cuihua [School of Physics and Nuclear Energy Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083 (China); Zhang Jian [Hainan Airlines Group, Hainan 570206 (China)

    2011-05-01

    The boron-doped diamond film (BDD) grown on tantalum (Ta) substrate as an electrode (BDD/Ta) was prepared by hot filament chemical vapor deposition method. The experimental results demonstrated that our BDD/Ta had high current efficiency, strong ability to degrade wastewater, good corrosion stability and long lifetime. These excellent characteristics of BDD/Ta have been explained in terms of Rutherford backscattering (RBS) experiments. RBS investigation revealed that the continuous transient layer at the interface between boron-doped diamond film and Ta-substrate was formed and the microstructure of the continuous transient layer given by the continuous distribution of all element contents at the interface was obtained. The thicknesses of boron-doped diamond film and the continuous transient layer were about equal to 8000 x 10{sup 15} atoms/cm{sup 2} and 5800 x 10{sup 15} atoms/cm{sup 2}, respectively. The formation of the continuous transient layer at the interface can eliminate the mismatch of thermal expansion coefficients (TEC) at the interface and only lead to the slow change of TEC because of the continuous distribution of element contents of the film and substrate in the transient layer at the interface. Thus, there is no residual stress to concentrate on the interface and the stress-corrosion delamination of the film disappears. Therefore, the corrosion stability and lifetime of BDD/Ta increase and last well, that have been verified by X-ray diffraction (XRD) experiments.

  11. Undoped and boron doped diamond nanoparticles as platinum and platinum-ruthenium catalyst support for direct methanol fuel cell application

    Science.gov (United States)

    La Torre Riveros, Lyda

    Nanoparticular diamond is a promising material that can be used as a robust and chemically stable catalytic support. It has been studied and characterized physically and electrochemically, in its powder and thin film forms. This thesis work intends to demonstrate that undoped diamond nanoparticles (DNPs) and boron-doped diamond nanoparticles (BDDNPs) can be used as an electrode and a catalytic support material for platinum and ruthenium catalysts. The electrochemical properties of diamond nanoparticle electrodes, fabricated using the ink paste method, were investigated. As an initial step, we carried out chemical purification of commercially available undoped DNPs by refluxing in aqueous HNO3 as well as of BDDNPs which were doped through a collaborative work with the University of Missouri. The purified material was characterized by spectroscopic and surface science techniques. The reversibility of reactions such as ferricyanide/ferrocyanide (Fe(CN) 63-/Fe(CN)64-) and hexaamineruthenium (III) chloride complexes as redox probes were evaluated by cyclic voltammetry at the undoped DNPs and BDDNPs surface. These redox probes showed limited peak currents and presented linear relationships between current (i) and the square root of the potential scan rate (v1/2). However, compared to conventional electrodes, the peak currents were smaller. BDDNPs show an improvement in charge transfer currents when compared to undoped DNPs. Platinum and ruthenium nanoparticles were chemically deposited on undoped DNPs and BDDNPs through the use of the excess of a mild reducing agent such NaBH4. In order to improve the nanoparticle dispersion sodium dodecyl benzene sulfonate (SDBS), a surfactant agent, was used. Percentages of platinum and ruthenium metals were varied as well as the stoichiometric amount of the reducing agent to determine adequate parameters for optimum performance in methanol oxidation. Both before and after the reducing process the samples were characterized by scanning

  12. Highly sensitive detection of influenza virus by boron-doped diamond electrode terminated with sialic acid-mimic peptide.

    Science.gov (United States)

    Matsubara, Teruhiko; Ujie, Michiko; Yamamoto, Takashi; Akahori, Miku; Einaga, Yasuaki; Sato, Toshinori

    2016-08-01

    The progression of influenza varies according to age and the presence of an underlying disease; appropriate treatment is therefore required to prevent severe disease. Anti-influenza therapy, such as with neuraminidase inhibitors, is effective, but diagnosis at an early phase of infection before viral propagation is critical. Here, we show that several dozen plaque-forming units (pfu) of influenza virus (IFV) can be detected using a boron-doped diamond (BDD) electrode terminated with a sialic acid-mimic peptide. The peptide was used instead of the sialyloligosaccharide receptor, which is the common receptor of influenza A and B viruses required during the early phase of infection, to capture IFV particles. The peptide, which was previously identified by phage-display technology, was immobilized by click chemistry on the BDD electrode, which has excellent electrochemical characteristics such as low background current and weak adsorption of biomolecules. Electrochemical impedance spectroscopy revealed that H1N1 and H3N2 IFVs were detectable in the range of 20-500 pfu by using the peptide-terminated BDD electrode. Our results demonstrate that the BDD device integrated with the receptor-mimic peptide has high sensitivity for detection of a low number of virus particles in the early phase of infection. PMID:27457924

  13. XPS study of ruthenium tris-bipyridine electrografted from diazonium salt derivative on microcrystalline boron doped diamond.

    Science.gov (United States)

    Agnès, Charles; Arnault, Jean-Charles; Omnès, Franck; Jousselme, Bruno; Billon, Martial; Bidan, Gérard; Mailley, Pascal

    2009-12-28

    Boron doped diamond (BDD) functionalization has received an increasing interest during the last few years. Such an infatuation comes from the original properties of BDD, including chemical stability or an electrochemical window, that opens the way for the design of (bio)sensors or smart interfaces. In such a context, diazonium salts appear to be well suited for BDD functionalization as they enable covalent immobilization of functional entities such as enzymes or DNA. In this study we report microcrystalline BDD functionalization with a metallic complex, ruthenium tris(bipyridine), using the p-(tris(bipyridine)Ru(2+))phenyl diazonium salt. Electrografting using cyclic voltammetry (CV) allowed the formation of a ruthenium complex film that was finely characterized using electrochemistry and X-ray photoelectron spectroscopy (XPS). Moreover, we showed that chronopotentiometry (CP) is a convenient tool to monitor Ru complex film deposition through the control of the electrochemical pulse parameters (i.e. current density and pulse duration). Finally, such a control was demonstrated through the correlation between electrochemical and XPS characterizations. PMID:20024438

  14. Development of an electrochemical sensor for the determination of the total antioxidant capacity in berries based on boron doped diamond

    Directory of Open Access Journals (Sweden)

    BRUNA PEKEC

    2013-02-01

    Full Text Available Many antioxidants can be electrochemically oxidized using graphite-based electrodes; nevertheless problems arise due to the strong adsorption of redox species at the sensing area. We have demonstrated that boron doped diamond (BDD electrodes do not show this property, which can be exploited for the design of a new amperometric sensor for the quantification of antioxidants as “total antioxidant capacity” (AOC. As reference substances hydroquinone (HQ and 6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox were studied in more detail. The supporting electrolyte was a phosphate buffer solution (PBS, 0.1 mol/L, pH 7.0. The limits of detection (LOD were 1.5 mg/L and 2.5 mg/L for HQ and Trolox, respectively. The repeatability was 3 % RSD for concentration of 200 mg/L HQ. The method could be applied for the determination of AOC in different berry samples, such as strawberry, blueberry, grape and bramble. A comparison with a standard photometric assay showed good correlation between both methods. The BDD sensor features good reproducibility without fatiguing over at least two months of operation.

  15. Anodic oxidation of ketoprofen-An anti-inflammatory drug using boron doped diamond and platinum electrodes

    International Nuclear Information System (INIS)

    The mineralization of ketoprofen (KP) by anodic oxidation was studied by employing boron doped diamond (BDD) and Pt electrodes. The redox behavior of KP molecule, fouling of electrodes, generation of oxygen and active chlorine species were studied by cyclic voltammetry. The effect of electrolyte, pH of aqueous medium and applied current density on the mineralization behavior of KP was also investigated. The degradation and mineralization were monitored by UV-vis spectrophotometer and total organic carbon analyzer, respectively. The results were explained in terms of in situ generation of hydroxyl radical (·OH), peroxodisulfate (S2O82-), and active chlorine species (Cl2, HOCl, OCl-). The physisorbed ·OH on BDD was observed to trigger the combustion of KP in to CO2 and H2O. The poor mineralization at both BDD and Pt anodes in the presence of NaCl as supporting electrolyte was ascribed to the formation of chlorinated organic compounds which are refractory. Complete mineralization of KP molecule was achieved using Na2SO4 as supporting electrolyte.

  16. Electrochemical disinfection using boron-doped diamond electrode--the synergetic effects of in situ ozone and free chlorine generation.

    Science.gov (United States)

    Rajab, Mohamad; Heim, Carolin; Letzel, Thomas; Drewes, Jörg E; Helmreich, Brigitte

    2015-02-01

    This work investigated the capability of using a boron-doped diamond (BDD) electrode for bacterial disinfection in different water matrices containing varying amounts of chloride. The feed water containing Pseudomonas aeruginosa was electrochemically treated while applying different electrode conditions. Depending on the applied current density and the exposure time, inactivation between 4- and 8-log of the targeted microorganisms could be achieved. The disinfection efficiency was driven by the generation of free chlorine as a function of chloride concentration in the water. A synergetic effect of generating both free chlorine and ozone in situ during the disinfection process resulted in an effective bactericidal impact. The formation of the undesired by-products chlorate and perchlorate depended on the water matrix, the applied current density and the desired target disinfection level. In case of synthetic water with a low chloride concentration (20 mg L(-1)) and an applied current density of 167 mA cm(-2), a 6-log inactivation of Pseudomonas aeruginosa could be achieved after 5 min of exposure. The overall energy consumption ranged between 0.3 and 0.6 kW h m(-3) depending on the applied current density and water chemistry. Electrochemical water disinfection represents a suitable and efficient process for producing pathogen-free water without the use of any chemicals.

  17. Applicability of boron-doped diamond electrode to the degradation of chloride-mediated and chloride-free wastewaters

    International Nuclear Information System (INIS)

    The electrochemical degradation of chloride-mediated and chloride-free dye wastewaters was investigated on a boron-doped diamond (BDD) electrode in comparison with that on a dimensionally stable anode (DSA), and the applicability of BDD electrode to the degradation of these two kinds of wastewaters was explored. In chloride-free wastewater, the electrochemical degradation efficiency of dye on BDD electrode was much higher than that on DSA, with a chemical oxygen demand (COD) removal of 100% and 26% for BDD and DSA, respectively. In chloride-mediated dye wastewater, COD removal was faster than that in chloride-free wastewater on both BDD and DSA electrodes with COD removal efficiencies higher than 95%, whereas the rate of COD removal on DSA was faster than that on BDD electrode. The investigation indicates that DSA is more suitable than BDD electrode in degradation of originally chloride contained dye wastewaters for the sake of energy and time saving. However, for chloride-free dye wastewaters, with the aim of environmental protection, BDD electrode is more appropriate to realize complete mineralization. At the same time, the secondary pollution can be avoided

  18. Simultaneous square-wave voltammetric determination of aspartame and cyclamate using a boron-doped diamond electrode.

    Science.gov (United States)

    Medeiros, Roberta Antigo; de Carvalho, Adriana Evaristo; Rocha-Filho, Romeu C; Fatibello-Filho, Orlando

    2008-07-30

    A simple and highly selective electrochemical method was developed for the simultaneous determination of aspartame and cyclamate in dietary products at a boron-doped diamond (BDD) electrode. In square-wave voltammetric (SWV) measurements, the BDD electrode was able to separate the oxidation peak potentials of aspartame and cyclamate present in binary mixtures by about 400 mV. The detection limit for aspartame in the presence of 3.0x10(-4) mol L(-1) cyclamate was 4.7x10(-7) mol L(-1), and the detection limit for cyclamate in the presence of 1.0x10(-4) mol L(-1) aspartame was 4.2x10(-6) mol L(-1). When simultaneously changing the concentration of both aspartame and cyclamate in a 0.5 mol L(-1) sulfuric acid solution, the corresponding detection limits were 3.5x10(-7) and 4.5x10(-6) mol L(-1), respectively. The relative standard deviation (R.S.D.) obtained was 1.3% for the 1.0x10(-4) mol L(-1) aspartame solution (n=5) and 1.1% for the 3.0x10(-3) mol L(-1) cyclamate solution. The proposed method was successfully applied in the determination of aspartame in several dietary products with results similar to those obtained using an HPLC method at 95% confidence level.

  19. Electrochemical Sensing and Assessment of Parabens in Hydro- Alcoholic Solutions and Water Using a Boron-Doped Diamond Electrode

    Directory of Open Access Journals (Sweden)

    Vasile Ostafe

    2008-07-01

    Full Text Available In this paper, the electrochemical behaviour of several parabens preservatives, i.e. esters of p-hydroxybenzoic acid, methyl-, ethyl- and propyl-4-hydroxybenzoates as methyl-, ethyl- and propyl-parabens (MB, EB, and PB, has been investigated at a commercial boron-doped diamond electrode (BDDE, especially in the anodic potential range, in both hydro-alcoholic and aqueous media. The cyclic voltammetric and chronoamperometric measurements yielded calibration plots with very good linearity (R2 between 0.990 and 0.998 and high sensitivity, useful for detection and analytical applications. The determination of the characteristics of individual compounds, of an “overall paraben index”, the assessment of the stability and the saturation solubility in water, and the amperometric sensing and determination in double distilled, tap and river water matrix of the relatively slightly soluble investigated parabens have been carried out using electrochemical alternative. Estimated water solubility was correlated with the octanol-water partition coefficient. Several ideas regarding stability and persistence of the presumptive eco-toxic investigated preservatives in the environment or water systems have been adjacently discussed.

  20. Biofouling resistance of boron-doped diamond neural stimulation electrodes is superior to titanium nitride electrodes in vivo

    Science.gov (United States)

    Meijs, S.; Alcaide, M.; Sørensen, C.; McDonald, M.; Sørensen, S.; Rechendorff, K.; Gerhardt, A.; Nesladek, M.; Rijkhoff, N. J. M.; Pennisi, C. P.

    2016-10-01

    Objective. The goal of this study was to assess the electrochemical properties of boron-doped diamond (BDD) electrodes in relation to conventional titanium nitride (TiN) electrodes through in vitro and in vivo measurements. Approach. Electrochemical impedance spectroscopy, cyclic voltammetry and voltage transient (VT) measurements were performed in vitro after immersion in a 5% albumin solution and in vivo after subcutaneous implantation in rats for 6 weeks. Main results. In contrast to the TiN electrodes, the capacitance of the BDD electrodes was not significantly reduced in albumin solution. Furthermore, BDD electrodes displayed a decrease in the VTs and an increase in the pulsing capacitances immediately upon implantation, which remained stable throughout the whole implantation period, whereas the opposite was the case for the TiN electrodes. Significance. These results reveal that BDD electrodes possess a superior biofouling resistance, which provides significantly stable electrochemical properties both in protein solution as well as in vivo compared to TiN electrodes.

  1. Electrochemical degradation of the antihypertensive losartan in aqueous medium by electro-oxidation with boron-doped diamond electrode.

    Science.gov (United States)

    Salazar, Claudio; Contreras, Nicole; Mansilla, Héctor D; Yáñez, Jorge; Salazar, Ricardo

    2016-12-01

    In this work the electrochemical oxidation of losartan, an emerging pharmaceutical pollutant, was studied. Electrochemical oxidation was carried out in batch mode, in an open and undivided cell of 100cm(3) using a boron-doped diamond (BDD)/stainless steel system. With Cl(-) medium 56% of mineralization was registered, while with the trials containing SO4(2-) as supporting electrolyte a higher mineralization yield of 67% was reached, even obtaining a total removal of losartan potassium at 80mAcm(-2) and 180min of reaction time at pH 7.0. Higher losartan potassium concentrations enhanced the mineralization degree and the efficiency of the electrochemical oxidation process. During the mineralization up to 4 aromatic intermediates were identified by ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Moreover, short-linear carboxylic acids, like oxalic, succinic and oxamic were detected and quantified by ion-exclusion HPLC. Finally, the ability of the electrochemical oxidation process to mineralize dissolved commercial tablets containing losartan was achieved, obtaining TOC removal up to 71% under optimized conditions (10mAcm(-2), 0.05M Na2SO4, pH 7.0 and 25°C and 360min of electrolysis). PMID:27180209

  2. Determination of propylthiouracil in pharmaceuticals by differential pulse voltammetry using a cathodically pretreated boron-doped diamond electrode

    Energy Technology Data Exchange (ETDEWEB)

    Sartori, Elen Romao [Universidade Estadual de Londrina, PR (Brazil). Dept. de Quimica; Trench, Aline Barrios; Rocha-Filho, Romeu C.; Fatibello-Filho, Orlando, E-mail: bello@ufscar.br [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica

    2013-09-15

    A simple procedure is described for the determination of propylthiouracil (PTU) by differential pulse voltammetry (DPV) using a cathodically pretreated boron-doped diamond (BDD) electrode. Cyclic voltammetry studies indicate that the oxidation of PTU is irreversible at a peak potential of 1.42 V (vs. Ag/AgCl (3.0 mol L{sup -1} KCl)) in a Britton-Robinson (BR) buffer solution (pH 2.0). Under optimized conditions, the obtained analytical curve was linear (r = 0.9985) for the PTU concentration range of 1.0 to 29.1 {mu}mol L{sup -1} in a BR buffer solution (pH 2.0), with a detection limit of 0.90 {mu}mol L{sup -1}. The proposed method was successfully applied in the determination of PTU in pharmaceutical samples, with results in agreement at a 95% confidence level with those obtained using an official titration method. (author)

  3. Simultaneous determination of paracetamol and ibuprofen in pharmaceutical samples by differential pulse voltammetry using a boron-doped diamond electrode

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Amanda B.; Guimaraes, Carlos F.R.C.; Verly, Rodrigo M.; Silva, Leonardo M. da [Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, MG (Brazil). Departamento de Quimica; Torres, Livia M.F.C.; Carvalho Junior, Alvaro D.; Santos, Wallans T. P. dos, E-mail: wallanst@ufvjm.edu.br [Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, MG (Brazil). Departamento de Farmacia

    2014-03-15

    This work presents a simple, fast and low-cost methodology for the simultaneous determination of paracetamol (PC) and ibuprofen (IB) in pharmaceutical formulations by differential pulse voltammetry using a boron-doped diamond (BDD) electrode. A well-defined oxidation peak was observed using the BDD electrode for each analyte (0.85 V for PC and 1.72 V for IB (vs. Ag/AgCl)) in 0.1 mol L{sup -1} H{sub 2}SO{sub 4} solution containing 10% (v/v) of ethanol. Calibration curves for the simultaneous determination of PC and IB showed a linear response for both drugs in a concentration range of 20 to 400 μmol L{sup -1} (r{sup 2} = 0.999), with a detection limit of 7.1 μmol L{sup -1} for PC and 3.8 μmol L{sup -1} for IB. The addition-recovery studies in samples were about 100% and the results were validated by chromatographic methods. (author)

  4. Removal of organic contaminants from secondary effluent by anodic oxidation with a boron-doped diamond anode as tertiary treatment

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Segura, Sergi, E-mail: sergigarcia@ub.edu [Advanced Water Management Centre, The University of Queensland, Level 4, Gehrmann Bld. (60), St Lucia, QLD 072 (Australia); Laboratori d’Electroquímica dels Materials i del Medi Ambient, Departament de Química Física, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona (Spain); Keller, Jürg [Advanced Water Management Centre, The University of Queensland, Level 4, Gehrmann Bld. (60), St Lucia, QLD 072 (Australia); Brillas, Enric [Laboratori d’Electroquímica dels Materials i del Medi Ambient, Departament de Química Física, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona (Spain); Radjenovic, Jelena, E-mail: j.radjenovic@awmc.uq.edu.au [Advanced Water Management Centre, The University of Queensland, Level 4, Gehrmann Bld. (60), St Lucia, QLD 072 (Australia)

    2015-02-11

    Graphical abstract: - Highlights: • Mineralization of secondary effluent by anodic oxidation with BDD anode. • Complete removal of 29 pharmaceuticals and pesticides at trace level concentrations. • Organochlorine and organobromine byproducts were formed at low μM concentrations. • Chlorine species evolution assessed to evaluate the anodic oxidation applicability. - Abstract: Electrochemical advanced oxidation processes (EAOPs) have been widely investigated as promising technologies to remove trace organic contaminants from water, but have rarely been used for the treatment of real waste streams. Anodic oxidation with a boron-doped diamond (BDD) anode was applied for the treatment of secondary effluent from a municipal sewage treatment plant containing 29 target pharmaceuticals and pesticides. The effectiveness of the treatment was assessed from the contaminants decay, dissolved organic carbon and chemical oxygen demand removal. The effect of applied current and pH was evaluated. Almost complete mineralization of effluent organic matter and trace contaminants can be obtained by this EAOP primarily due to the action of hydroxyl radicals formed at the BDD surface. The oxidation of Cl{sup −} ions present in the wastewater at the BDD anode gave rise to active chlorine species (Cl{sub 2}/HClO/ClO{sup −}), which are competitive oxidizing agents yielding chloramines and organohalogen byproducts, quantified as adsorbable organic halogen. However, further anodic oxidation of HClO/ClO{sup −} species led to the production of ClO{sub 3}{sup −} and ClO{sub 4}{sup −} ions. The formation of these species hampers the application as a single-stage tertiary treatment, but posterior cathodic reduction of chlorate and perchlorate species may reduce the risks associated to their presence in the environment.

  5. Removal of organic contaminants from secondary effluent by anodic oxidation with a boron-doped diamond anode as tertiary treatment

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Mineralization of secondary effluent by anodic oxidation with BDD anode. • Complete removal of 29 pharmaceuticals and pesticides at trace level concentrations. • Organochlorine and organobromine byproducts were formed at low μM concentrations. • Chlorine species evolution assessed to evaluate the anodic oxidation applicability. - Abstract: Electrochemical advanced oxidation processes (EAOPs) have been widely investigated as promising technologies to remove trace organic contaminants from water, but have rarely been used for the treatment of real waste streams. Anodic oxidation with a boron-doped diamond (BDD) anode was applied for the treatment of secondary effluent from a municipal sewage treatment plant containing 29 target pharmaceuticals and pesticides. The effectiveness of the treatment was assessed from the contaminants decay, dissolved organic carbon and chemical oxygen demand removal. The effect of applied current and pH was evaluated. Almost complete mineralization of effluent organic matter and trace contaminants can be obtained by this EAOP primarily due to the action of hydroxyl radicals formed at the BDD surface. The oxidation of Cl− ions present in the wastewater at the BDD anode gave rise to active chlorine species (Cl2/HClO/ClO−), which are competitive oxidizing agents yielding chloramines and organohalogen byproducts, quantified as adsorbable organic halogen. However, further anodic oxidation of HClO/ClO− species led to the production of ClO3− and ClO4− ions. The formation of these species hampers the application as a single-stage tertiary treatment, but posterior cathodic reduction of chlorate and perchlorate species may reduce the risks associated to their presence in the environment

  6. Electrochemical degradation of 17{beta}-estradiol (E2) at boron-doped diamond (Si/BDD) thin film electrode

    Energy Technology Data Exchange (ETDEWEB)

    Murugananthan, M. [Department of Energy and Environmental Science, Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585 (Japan)]. E-mail: muruga.chem@gmail.com; Yoshihara, S. [Department of Energy and Environmental Science, Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585 (Japan)]. E-mail: sachioy@cc.utsunomiya-u.ac.jp; Rakuma, T. [Department of Energy and Environmental Science, Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585 (Japan); Uehara, N. [Department of Energy and Environmental Science, Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585 (Japan); Shirakashi, T. [Department of Energy and Environmental Science, Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585 (Japan)

    2007-02-15

    Electrochemical degradation of aqueous solutions containing 17{beta}-estradiol (E2), concentrations range of 250-750 {mu}g dm{sup -3}, has been extensively studied using boron-doped diamond (BDD) anode with a working solution volume of 250 ml under galvanostatic control. Cyclic voltammetric experiments were performed to examine the redox response of E2 as a function of cycle number. The effect of operating variables such as initial concentration of E2, applied current density, supporting medium (Na{sub 2}SO{sub 4}, NaNO{sub 3}, and NaCl) and initial pH of the electrolyte (pH 2-10) were systematically examined and discussed. Electrolysis at high anodic potential causes complex oxidation of E2 that leads to form the final sole product as CO{sub 2}. A pseudo first-order kinetics for E2 decay was found against varying applied current density. Also, kinetic analysis suggests that electrooxidation reaction of E2 undergo the control of applied current density. It was observed that electrolyte pH and supporting medium have a vital role on E2 degradation. From a comparison study with other anode materials such as platinum (Pt) and glassy carbon (GC), the superiority of the BDD anode was proved. Total organic carbon results have shown that almost complete mineralization could be accomplished at higher applied current density with specific electrical charge 22.5 x 10{sup -2} A h dm{sup -3}. Mineralization current efficiency was comparatively lower with increasing applied current density.

  7. Determination of parabens in shampoo using high performance liquid chromatography with amperometric detection on a boron-doped diamond electrode.

    Science.gov (United States)

    Martins, Isarita; Carreira, Franciely Cristiani; Canaes, Larissa S; de Souza Campos Junior, Francisco Alberto; da Silva Cruz, Letícia Maria; Rath, Susanne

    2011-07-15

    Methylparaben (MePa), ethylparaben (EtPa) and propylparaben (PrPa) have been widely used, among others, as chemical preservatives in cosmetics, drugs and foods. As these compounds are linked with allergies, dermatitis and estrogenic properties, it is necessary to control the concentration of these substances in different matrices. The aim of this paper are: to evaluate the electrochemical behavior of parabens on the boron-doped diamond (BDD) electrode and the development of a chromatographic method, with electrochemical detection (HPLC-ED), for determination of parabens in shampoo. A BDD (8000 ppm) electrode was adapted in a thin layer mode analytical cell consisting of a stainless steel and a platinum wire as reference and auxiliary electrodes, respectively. Chromatographic separations were obtained with a reversed phase C8 analytical column and a mobile phase of 0.025 molL(-1) disodium phosphate, pH 7.0, and acetonitrile (40:60, v/v), delivered at a flow rate of 1.0 mL min(-1). Sample preparation was performed by solid phase extraction using C18 cartridges and acetonitrile for elution. Benzylparaben was employed as internal standard. The HPLC-ED method developed, using the BDD electrode, was validated for the determination of parabens in shampoos and presented adequate linearity (>0.999), in the range of 0.0125-0.500% (w/w), detectability 0.01% (w/w), precision (RSD of 2.3-9.8%) and accuracy (93.1-104.4%) and could be applied for routine quality control of shampoos containing MePa, EtPa and PrPa.

  8. Surface Roughness and Critical Exponent Analyses of Boron-Doped Diamond Films Using Atomic Force Microscopy Imaging: Application of Autocorrelation and Power Spectral Density Functions

    Science.gov (United States)

    Gupta, S.; Vierkant, G. P.

    2014-09-01

    The evolution of the surface roughness of growing metal or semiconductor thin films provides much needed information about their growth kinetics and corresponding mechanism. While some systems show stages of nucleation, coalescence, and growth, others exhibit varying microstructures for different process conditions. In view of these classifications, we report herein detailed analyses based on atomic force microscopy (AFM) characterization to extract the surface roughness and growth kinetics exponents of relatively low boron-doped diamond (BDD) films by utilizing the analytical power spectral density (PSD) and autocorrelation function (ACF) as mathematical tools. The machining industry has applied PSD for a number of years for tool design and analysis of wear and machined surface quality. Herein, we present similar analyses at the mesoscale to study the surface morphology as well as quality of BDD films grown using the microwave plasma-assisted chemical vapor deposition technique. PSD spectra as a function of boron concentration (in gaseous phase) are compared with those for samples grown without boron. We find that relatively higher boron concentration yields higher amplitudes of the longer-wavelength power spectral lines, with amplitudes decreasing in an exponential or power-law fashion towards shorter wavelengths, determining the roughness exponent ( α ≈ 0.16 ± 0.03) and growth exponent ( β ≈ 0.54), albeit indirectly. A unique application of the ACF, which is widely used in signal processing, was also applied to one-dimensional or line analyses (i.e., along the x- and y-axes) of AFM images, revealing surface topology datasets with varying boron concentration. Here, the ACF was used to cancel random surface "noise" and identify any spatial periodicity via repetitive ACF peaks or spatially correlated noise. Periodicity at shorter spatial wavelengths was observed for no doping and low doping levels, while smaller correlations were observed for relatively

  9. Interaction of organophosphorus pesticides with DNA nucleotides on a Boron-doped diamond electrode

    International Nuclear Information System (INIS)

    Diamond electrode was used to evaluate the interaction of the nucleotides guanosine monophosphate (GMP) and adenosine monophosphate (AMP) with the pesticides chlorpyrifos, methamidophos and monocrotophos. Changes were observed in the currents and peak potentials of the nucleotide voltammograms in the presence of the pesticides, with dependence on the pesticide concentration (from 5.0 × 10-7 to 5.0 × 10-5 mol L-1) and the interaction time (from 1 min to 4 h). This is probably due to binding of the pesticides to the nitrogenous bases present in the nucleotides, which could lead to problems in the DNA replication and biological functions of nucleotides. The pesticides showed stronger interaction with AMP than with GMP. Studies of the interaction of 50 µg mL-1 DNA with the pesticides (from 30 min to 4 h and from 1.0 × 10-6 to 6.0 × 10-5 mol L-1) did not reveal any peaks relating to double helix opening or DNA unwinding. (author)

  10. Interaction of organophosphorus pesticides with DNA nucleotides on a Boron-doped diamond electrode

    Energy Technology Data Exchange (ETDEWEB)

    Garbellini, Gustavo S.; Uliana, Carolina V.; Yamanaka, Hideko, E-mail: gustgarb@yahoo.com.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Bauru, SP (Brazil). Dept. de Quimica Analitica

    2013-12-01

    Diamond electrode was used to evaluate the interaction of the nucleotides guanosine monophosphate (GMP) and adenosine monophosphate (AMP) with the pesticides chlorpyrifos, methamidophos and monocrotophos. Changes were observed in the currents and peak potentials of the nucleotide voltammograms in the presence of the pesticides, with dependence on the pesticide concentration (from 5.0 Multiplication-Sign 10{sup -7} to 5.0 Multiplication-Sign 10{sup -5} mol L{sup -1}) and the interaction time (from 1 min to 4 h). This is probably due to binding of the pesticides to the nitrogenous bases present in the nucleotides, which could lead to problems in the DNA replication and biological functions of nucleotides. The pesticides showed stronger interaction with AMP than with GMP. Studies of the interaction of 50 Micro-Sign g mL{sup -1} DNA with the pesticides (from 30 min to 4 h and from 1.0 Multiplication-Sign 10{sup -6} to 6.0 Multiplication-Sign 10{sup -5} mol L{sup -1}) did not reveal any peaks relating to double helix opening or DNA unwinding. (author)

  11. Electrochemical characterisation and oxygen evolution at a heavily boron doped diamond electrode

    International Nuclear Information System (INIS)

    Characterisation of a commercial heavily doped BDD electrode demonstrated it contains a small sp2 content, which on anodic potential scanning, is oxidised to CO/CO2. This surface modification alters the electrode activity, increasing the overpotential for the hydrogen and oxygen evolution reactions (HER and OER). Ex situ and in situ investigations indicate film morphology is mainly composed of 'chain of hills', presenting relatively high differential capacitance values and morphology factor, which is attributed to the effect of surface states and high surface roughness of the BDD film. The voltammetric behaviour depends on the applied potential; the heavily doped BDD electrode behaving as a metallic electrode at more anodic potentials. Polarisation curves (potentiostatic (1 mV s-1) or galvanostatic (point-by-point)), recorded at different temperatures and H2SO4 concentrations, lead to the same conclusions. The high Tafel coefficients and low apparent electronic transfer coefficient (αA) are independent of overpotential and temperature but show a dependence on H2SO4 concentration. The linear relationship observed between the apparent electrochemical enthalpy of activation (ΔHhashmarkη) and overpotential supports αA is constant. An OER mechanism was proposed taking into account the absence of adsorption sites at the BDD surface. The OER is inhibited, explaining the high overpotentials and elevated ΔHhashmar'Kη values

  12. Electrochemical oxidation of amoxicillin in its pharmaceutical formulation at boron doped diamond (BDD electrode

    Directory of Open Access Journals (Sweden)

    Corneil Quand-Meme Gnamba

    2015-08-01

    Full Text Available In this work, voltammetric andelectrolysis experiments have been carried out on a conductive boron dopeddiamond (BDD electrode in solution containing amoxicillin in itspharmaceutical formulation. The physical characterization of the BDD surface byscanning electron microscopy (SEM reveals a polycrystalline structure withgrain sizes ranging between 0.3 and 0.6 µm. With Raman spectroscopy, BDDsurface is composed of diamons (Csp3 type carbon (Csp3and graphitic type carbon (Csp2. The electrochemical characterization of the BDD electrode in sulfuric acid electrolyte showed a wide potential window worthing 2.74 V. The oxidation of Amoxicillin showed an irreversible anodic wave on the voltammogram in the domain of water stability indicating a direct oxidation of amoxicillin at BDD surface. The treatment of Amoxicillin in the synthetic wastewaters under various constant current densities 20, 50, 100, 135 mA cm-2 on BDD showed that Amoxicillin is highly reducedunder 100 mA cm-2 reaching 92% of the Chemical Oxygen Demand (CODremoval after 5 h of electrolysis. Investigation performed in perchloric acidas supporting electrolyte led to 87% of COD removal after 5 h of electrolysis.Mineralization of amoxicillin occurs on BDD and the chemical oxygen demandremoval was higher in sulfuric acid than in perchloric acid owing to theinvolvement of the in-situ formed persulfate and perchlorate  to the degradation process mainly in the bulkof the solution. The instantaneous current efficiency (ICE presents anexponential decay indicating that the process was limited by diffusion. Thespecific energy consumed after 5h of the amoxicillin electrolysis was 0.096 kWh COD-1and 0.035 kWh COD-1 in sulfuric acid and in perchloric acidrespectively.

  13. Hydrogenation effects on carrier transport in boron-doped ultrananocrystalline diamond/amorphous carbon films prepared by coaxial arc plasma deposition

    Energy Technology Data Exchange (ETDEWEB)

    Katamune, Yūki, E-mail: yuki-katamune@kyudai.jp; Takeichi, Satoshi [Department of Applied Science for Electronics and Materials, Kyushu University, 6-1 Kasuga, Fukuoka 816-8580 (Japan); Ohmagari, Shinya [Diamond Research Group, Research Institute for Ubiquitous Energy Devices (UBIQEN), National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan); Yoshitake, Tsuyoshi, E-mail: tsuyoshi-yoshitake@kyudai.jp [Department of Applied Science for Electronics and Materials, Kyushu University, 6-1 Kasuga, Fukuoka 816-8580 (Japan); Research Center for Synchrotron Light Applications, Kyushu University, 6-1 Kasuga 816-8580 (Japan); Research and Education Center for Advanced Energy, Materials, Devices, and Systems, Kyushu University, 6-1 Kasuga 816-8580 (Japan)

    2015-11-15

    Boron-doped ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/a-C:H) films were deposited by coaxial arc plasma deposition with a boron-blended graphite target at a base pressure of <10{sup −3} Pa and at hydrogen pressures of ≤53.3 Pa. The hydrogenation effects on the electrical properties of the films were investigated in terms of chemical bonding. Hydrogen-scattering spectrometry showed that the maximum hydrogen content was 35 at. % for the film produced at 53.3-Pa hydrogen pressure. The Fourier-transform infrared spectra showed strong absorptions by sp{sup 3} C–H bonds, which were specific to the UNCD/a-C:H, and can be attributed to hydrogen atoms terminating the dangling bonds at ultrananocrystalline diamond grain boundaries. Temperature-dependence of the electrical conductivity showed that the films changed from semimetallic to semiconducting with increasing hydrogen pressure, i.e., with enhanced hydrogenation, probably due to hydrogenation suppressing the formation of graphitic bonds, which are a source of carriers. Carrier transport in semiconducting hydrogenated films can be explained by a variable-range hopping model. The rectifying action of heterojunctions comprising the hydrogenated films and n-type Si substrates implies carrier transport in tunneling.

  14. Influence of surface treatment and dopant concentration on field emission characteristics of boron-doped diamond thin films

    Energy Technology Data Exchange (ETDEWEB)

    Nagao, M.; Kondo, T.; Gotoh, Y.; Tsuji, H.; Ishikawa, J. [Department of Electronic Science and Engineering, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-01 (Japan); Miyata, K.; Kobashi, K. [Kobe Steel, Ltd., Electronics and Information Technology Laboratory, 5-5, 1-chome, Takatsuka-dai, Nishi-ku, Kobe 651-22 (Japan)

    1997-11-01

    Field emission characteristics of B-doped diamond thin films terminated with oxygen and hydrogen were investigated. The diamond thin films were prepared by microwave plasma chemical vapor deposition. The dependence of emission characteristics on the surface treatment and on the B concentration was investigated. The turn-on voltage required to extract a current of 0.1 nA depended on these preparation parameters. The emitters with lower B concentration emitted electrons at a lower turn-on voltage, and the H-terminated emitters had a lower turn-on voltage than O-terminated emitters. The analysis of the slope and the intercept of Fowler{endash}Nordheim plot revealed that the dependence of turn-on voltage on the surface treatment is due to the difference of emission barrier height, and that the dependence on B concentration is due not to the emission barrier height but to the surface morphology. {copyright} {ital 1997 American Institute of Physics.}

  15. Electrochemical oxidation of vinasses using a boron doped diamond electrode; Degradacao eletroquimica da vinhaca usando eletrodo de diamante dopado com boro

    Energy Technology Data Exchange (ETDEWEB)

    Batista, Eveline Cristine; Oliveira, Robson Tadeu Soares de, E-mail: robson@icbn.uftm.edu.br [Universidade Federal do Triangulo Mineiro, Uberaba, MG (Brazil). Inst. de Ciencias Biologicas e Naturais; Ferreira, Rafael de Queiroz [Universidade Federal do Espirito Santo (UFES), Vitoria, ES (Brazil). Dept. de Quimica; Miwa, Douglas [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Inst. de Quimica; Santos, Mauro Coelho dos [Universidade Federal do ABC, Santo Andre, SP (Brazil)

    2011-07-01

    The degradation of vinasses in aqueous solution from ethanol industry has been investigated by electrochemical oxidation using a boron doped diamond electrode (BDD). Samples of vinasses were electrolysed in medium of (0.1 mol L-1) Na{sub 2}SO{sub 4} solutions at controlled potentials of +2.4, +3.0 and +4.0 V (vs. Ag/AgCl) and exhibited considerable reduction of total organic carbon. The cyclic voltammetry studies indicate that the vinasses are oxidized irreversibly over the BDD at 2.0 V (vs. Ag/AgCl) in diffusion controlled process. From the experimental results it is clear that the BDD electrode can be a valuable tool to the electrochemical degradation of vinasses in practical applications. (author)

  16. Pulsed Amperometry for Anti-fouling of Boron-doped Diamond in Electroanalysis of β-Agonists: Application to Flow Injection for Pharmaceutical Analysis

    Directory of Open Access Journals (Sweden)

    Duangjai Nacapricha

    2006-01-01

    Full Text Available This work presents the construction and application of boron-doped diamond(BDD thin film electrode as sensor for the determination of three β-agonists, viz.salbutamol, terbutaline and clenbuterol. Although well-known as a chemically inertmaterial, BDD film however shows fouling in detection of these compounds using fixedpotentialmode amperometry. A suitable waveform for pulsed amperometric detection(PAD was developed and used to determine the agonist compounds. It was seen that thedeveloped PAD significantly refreshed the BDD surface for long-term detection in flowinjection analysis. Linear working ranges were 0.5-100 μM, 1.0-100 μM and 0.5-50 μM forsalbutamol, terbutaline and clenbuterol, respectively. The developed PAD-BDD system wasapplied to successfully determine salbutamol and terbutaline in commercial pharmaceuticalproducts. The methods were validated with a capillary electrophoresis method.

  17. Electroanalysis of sulfonamides by flow injection system/high-performance liquid chromatography coupled with amperometric detection using boron-doped diamond electrode.

    Science.gov (United States)

    Preechaworapun, Anchana; Chuanuwatanakul, Suchada; Einaga, Yasuaki; Grudpan, Kate; Motomizu, Shoji; Chailapakul, Orawon

    2006-02-28

    Sulfonamides (SAs) were electrochemically investigated using cyclic voltammetry at a boron-doped diamond (BDD) electrode. Comparison experiments were carried out using a glassy carbon electrode. The BDD electrode provided well-resolved oxidation, irreversible cyclic voltammograms and higher current signals when compared to the glassy carbon electrode. Results obtained from using the BDD electrode in a flow injection system coupled with amperometric detection were illustrated. The optimum potential from a hydrodynamic voltammogram was found to be 1100mV versus Ag/AgCl, which was chosen for the HPLC-amperometric system. Excellent results of linear range and detection limit were obtained. This method was also used for determination of sulfonamides in egg samples. The standard solutions of 5, 10, and 15ppm were spiked in a real sample, and percentage of recoveries was found to be between 90.0 and 107.7.

  18. High-sensitivity non-enzymatic glucose biosensor based on Cu(OH){sub 2} nanoflower electrode covered with boron-doped nanocrystalline diamond layer

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Huijun [Department of Chemical and Biological Engineering, Korea University, 1, 5-Ga, Anam-dong, Sungbuk-ku, Seoul 136-713 (Korea, Republic of); Kim, Jong-Hoon; Lee, Seung-Koo; Song, Min-Jung [School of Material and Science Engineering, Korea University, 1, 5-Ga, Anam-dong, Sungbuk-ku, Seoul 136-713 (Korea, Republic of); Yoon, Dong-Hwa [Department of Chemical and Biological Engineering, Korea University, 1, 5-Ga, Anam-dong, Sungbuk-ku, Seoul 136-713 (Korea, Republic of); Lim, Dae-Soon [School of Material and Science Engineering, Korea University, 1, 5-Ga, Anam-dong, Sungbuk-ku, Seoul 136-713 (Korea, Republic of); Hong, Suk-In, E-mail: sihong@korea.ac.kr [Department of Chemical and Biological Engineering, Korea University, 1, 5-Ga, Anam-dong, Sungbuk-ku, Seoul 136-713 (Korea, Republic of)

    2012-10-01

    A non-enzymatic biosensor was developed using boron-doped nanocrystalline diamond (BDND) based on a Cu electrode with Cu(OH){sub 2} dendritic architecture. The Cu(OH){sub 2} nanoflower electrode was covered with a BDND layer using an electrostatic self-assembly seeding method with nanodiamond particles and hot-filament chemical vapor deposition. X-ray diffraction and Raman spectral analysis confirmed that the BDND nanoflower electrode was synthesized onto Cu(OH){sub 2} nanoflowers. Field-emission scanning electron microscope images showed that the fabricated electrodes were nanoflowers possessing large surface areas. From cyclic voltammetry, the peak currents of an BDND/Cu(OH){sub 2}/Cu electrode was about 7, 6.2, and 5.9 times higher than that of the Cu foil, Cu(OH){sub 2}/Cu, and BDND/Cu electrodes, respectively. A biosensor based on BDND/Cu(OH){sub 2}/Cu exhibited excellent performance for glucose detection, and it had a linear detection range of 0 to 6 mM, a correlation coefficient of 0.9994, a low detection limit of 9 {mu}M, and a high sensitivity of 2.1592 mA mM{sup -1} cm{sup -1}. - Highlights: Black-Right-Pointing-Pointer Deposition of boron-doped nanocrystalline diamond on Cu(OH){sub 2} nanoflowers Black-Right-Pointing-Pointer Damage-free seeding process using electrostatic self-assembly seeding method Black-Right-Pointing-Pointer Non-enzymatic glucose sensor with high sensitivity of 2.1592 mA mM{sup -1} cm{sup -1}.

  19. Filmes de diamante CVD dopado com boro. Parte I . Histórico, produção e caracterização Boron-doped CVD diamond films. Part I. History, production and characterization

    Directory of Open Access Journals (Sweden)

    Rita de Cássia Mendes de Barros

    2005-03-01

    Full Text Available This review presents a brief account concerning the production, characterization and evolution of the knowledge in the area of diamond and boron-doped diamond films. The most important methods used for the growth of these films, such as chemical vapor deposition and high pressure/high temperature systems, as well as the several kinds of reactors which can be employed are reviewed. However, larger emphasis is given to the CVD method. Morphological, structural and electric properties of these films, as well as their role in the performance of voltammetric electrodes for electrochemistry and electroanalytical chemistry are also discussed.

  20. Electrochemical degradation of a real textile effluent using boron-doped diamond or {beta}-PbO{sub 2} as anode

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, Jose M.; Pereira, Gabriel F. [Departmento de Quimica, Universidade Federal de Sao Carlos, C. P. 676, 13560-970 Sao Carlos, SP (Brazil); Rocha-Filho, Romeu C., E-mail: romeu@dq.ufscar.br [Departmento de Quimica, Universidade Federal de Sao Carlos, C. P. 676, 13560-970 Sao Carlos, SP (Brazil); Bocchi, Nerilso; Biaggio, Sonia R. [Departmento de Quimica, Universidade Federal de Sao Carlos, C. P. 676, 13560-970 Sao Carlos, SP (Brazil)

    2011-09-15

    Highlights: {center_dot} Diamond anode enables total abatement of a real textile effluent COD with low energy consumption. {center_dot} Use of diamond anode enables excellent decolorization rate of effluent in the presence of Cl{sup -} ions. {center_dot} Diamond anode might be an excellent option for electrochemical treatment of real textile effluents. {center_dot} PbO{sub 2} anode, due to low cost and easiness of preparation, may be an option to decolorize the effluents. - Abstract: Constant current electrolyses are carried out in a filter-press reactor using a boron-doped diamond (Nb/BDD) or a Ti-Pt/{beta}-PbO{sub 2} anode, varying current density (j) and temperature. The degradation of the real textile effluent is followed by its decolorization and chemical oxygen demand (COD) abatement. The effect of adding NaCl (1.5 g L{sup -1}) on the degradation of the effluent is also investigated. The Nb/BDD anode yields much higher decolorization (attaining the DFZ limit) and COD-abatement rates than the Ti-Pt/{beta}-PbO{sub 2} anode, at any experimental condition. The best conditions are j = 5 mA cm{sup -2} and 55 {sup o}C, for the system's optimized hydrodynamic conditions. The addition of chloride ions significantly increases the decolorization rate; thus a decrease of more than 90% of the effluent relative absorbance is attained using an applied electric charge per unit volume of the electrolyzed effluent (Q{sub ap}) of only about 2 kA h m{sup -3}. Practically total abatement of the effluent COD is attained with the Nb/BDD anode using a Q{sub ap} value of only 7 kA h m{sup -3}, with an energy consumption of about 30 kW h m{sup -3}. This result allows to conclude that the Nb/BDD electrode might be an excellent option for the remediation of textile effluents.

  1. 硼掺杂金刚石电极及其电分析应用%Electroanalytical Applications of Boron Doped Diamond Electrode

    Institute of Scientific and Technical Information of China (English)

    高成耀; 常明; 李晓伟; 李翠平

    2011-01-01

    一种新电极材料的发明往往会推动电分析测试的发展.硼掺杂金刚石(BDD)电极在电分析中具备宽电势窗口、低背景电流、耐腐蚀稳定性高和低吸附的特点,因而在电分析化学中引起了广泛的兴趣.本文对BDD电极的制备、表征和基本电分析性质进行了介绍,并对其在毛细管电泳、生物传感电极、痕量金属离子检测、化学修饰电极及化学需氧量快速测定方面的应用进行了综述.%Discoveries of new materials have significant impact on development of new methods and instrumentation for eletroanalysis.Boron doped diamond (BDD) electrode occupies a special place as an electrode material with interesting applications in electroanalysis because of its superior properties such as a wide potential window, low background current responses, remarkable corrosion stability, an inert surface with low adsorption.BDD electrodes have attracted the interests of many researchers for electrophoresis.The object of this article is to discuss the recent results available in the literature concerning the application of BDD electrodes to electroanalysis such as capillary electrophoresis end-column detection, electrochemical biosensor, anodic stripping voltammetry for trace metal ion detection, modified diamond electrodes and chemical oxygen demand detection.

  2. Molecular Signature of Pseudomonas aeruginosa with Simultaneous Nanomolar Detection of Quorum Sensing Signaling Molecules at a Boron-Doped Diamond Electrode

    Science.gov (United States)

    Buzid, Alyah; Shang, Fengjun; Reen, F. Jerry; Muimhneacháin, Eoin Ó.; Clarke, Sarah L.; Zhou, Lin; Luong, John H. T.; O’Gara, Fergal; McGlacken, Gerard P.; Glennon, Jeremy D.

    2016-07-01

    Electroanalysis was performed using a boron-doped diamond (BDD) electrode for the simultaneous detection of 2-heptyl-3-hydroxy-4-quinolone (PQS), 2-heptyl-4-hydroxyquinoline (HHQ) and pyocyanin (PYO). PQS and its precursor HHQ are two important signal molecules produced by Pseudomonas aeruginosa, while PYO is a redox active toxin involved in virulence and pathogenesis. This Gram-negative and opportunistic human pathogen is associated with a hospital-acquired infection particularly in patients with compromised immunity and is the primary cause of morbidity and mortality in cystic fibrosis (CF) patients. Early detection is crucial in the clinical management of this pathogen, with established infections entering a biofilm lifestyle that is refractory to conventional antibiotic therapies. Herein, a detection procedure was optimized and proven for the simultaneous detection of PYO, HHQ and PQS in standard mixtures, biological samples, and P. aeruginosa spiked CF sputum samples with remarkable sensitivity, down to nanomolar levels. Differential pulse voltammetry (DPV) scans were also applicable for monitoring the production of PYO, HHQ and PQS in P. aeruginosa PA14 over 8 h of cultivation. The simultaneous detection of these three compounds represents a molecular signature specific to this pathogen.

  3. Electro-fenton and photoelectro-fenton degradation of sulfanilic acid using a boron-doped diamond anode and an air diffusion cathode.

    Science.gov (United States)

    El-Ghenymy, Abdellatif; Garrido, José Antonio; Centellas, Francesc; Arias, Conchita; Cabot, Pere Lluís; Rodríguez, Rosa María; Brillas, Enric

    2012-04-01

    The mineralization of sulfanilic acid has been studied by electro-Fenton (EF) and photoelectro-Fenton (PEF) reaction with UVA light using an undivided electrochemical cell with a boron-doped diamond (BDD) anode and an air diffusion cathode able to generate H(2)O(2). Organics were then oxidized by hydroxyl radicals formed at the anode surface from water oxidation and in the bulk from Fenton's reaction between generated H(2)O(2) and added Fe(2+). The UVA irradiation in PEF enhanced the production of hydroxyl radicals in the bulk, accelerating the removal of organics and photodecomposed intermediates like Fe(III)-carboxylate complexes. Partial decontamination of 1.39 mM sulfanilic acid solutions was achieved by EF until 100 mA cm(-2) at optimum conditions of 0.4 mM Fe(2+) and pH 3.0. The increase in current density and substrate content led to an almost total mineralization. In contrast, the PEF process was more powerful, yielding almost complete mineralization in less electrolysis time under comparable conditions. The kinetics for sulfanilic acid decay always followed a pseudo-first-order reaction. Hydroquinone and p-benzoquinone were detected as aromatic intermediates, whereas acetic, maleic, formic, oxalic, and oxamic acids were identified as generated carboxylic acids. NH(4)(+) ion was preferentially released in both treatments, along with NO(3)(-) ion in smaller proportion.

  4. Electrochemical treatment of phenolic waters in presence of chloride with boron-doped diamond (BDD) anodes: Experimental study and mathematical model

    Energy Technology Data Exchange (ETDEWEB)

    Mascia, Michele, E-mail: michele.mascia@unica.it [Dipartimento di Ingegneria Chimica e Materiali, Universita di Cagliari Piazza d' Armi 09123 Cagliari (Italy); Vacca, Annalisa; Polcaro, Anna Maria; Palmas, Simonetta; Ruiz, Jesus Rodriguez; Da Pozzo, Anna [Dipartimento di Ingegneria Chimica e Materiali, Universita di Cagliari Piazza d' Armi 09123 Cagliari (Italy)

    2010-02-15

    This work deals with an experimental and numerical study on the electrochemical treatment of waters containing phenolic compounds with boron-doped diamond (BDD) anodes. Anodic oxidation of m-cresol, as a model of phenolic compound, was investigated by galvanostatic electrolyses. The electrolyses were carried out under different experimental conditions by using an impinging-jet flow cell inserted in a hydraulic circuit in a closed loop. On the basis of the experimental results a mathematical model was implemented to simulate the effect of the chemistry of organic compounds and solution on the process, in particular the effect of chlorides on the kinetics of m-cresol oxidation. The effect of hydrodynamics of the cell on the mass transfer towards the electrode surface was also considered. The model was validated through comparison with experimental data: the results showed that the proposed model well interpreted the complex effect on removal efficiency of such operative parameters as current density, hydrodynamic of the reactor and chemistry of the solution. The model predictions were utilised to obtain quantitative information on the reaction mechanism, as well as to predict the performance of the process under different operative conditions, by calculating some relevant figures of merit.

  5. Study of degradation intermediates formed during electrochemical oxidation of pesticide residue 2,6-dichlorobenzamide (BAM) at boron doped diamond (BDD) and platinum-iridium anodes.

    Science.gov (United States)

    Madsen, Henrik Tækker; Søgaard, Erik Gydesen; Muff, Jens

    2014-08-01

    Electrochemical oxidation is a promising technique for degradation of otherwise recalcitrant organic micropollutants in waters. In this study, the applicability of electrochemical oxidation was investigated concerning the degradation of the groundwater pollutant 2,6-dichlorobenzamide (BAM) through the electrochemical oxygen transfer process with two anode materials: Ti/Pt90-Ir10 and boron doped diamond (Si/BDD). Besides the efficiency of the degradation of the main pollutant, it is also of outmost importance to control the formation and fate of stable degradation intermediates. These were investigated quantitatively with HPLC-MS and TOC measurements and qualitatively with a combined HPLC-UV and HPLC-MS protocol. 2,6-Dichlorobenzamide was found to be degraded most efficiently by the BDD cell, which also resulted in significantly lower amounts of intermediates formed during the process. The anodic degradation pathway was found to occur via substitution of hydroxyl groups until ring cleavage leading to carboxylic acids. For the BDD cell, there was a parallel cathodic degradation pathway that occurred via dechlorination. The combination of TOC with the combined HPLC-UV/MS was found to be a powerful method for determining the amount and nature of degradation intermediates. PMID:24873711

  6. The improvement of boron-doped diamond anode system in electrochemical degradation of p-nitrophenol by zero-valent iron

    International Nuclear Information System (INIS)

    Boron-doped diamond (BDD) electrodes are promising anode materials in electrochemical treatment of wastewaters containing bio-refractory organic compounds due to their strong oxidation capability and remarkable corrosion stability. In order to further improve the performance of BDD anode system, electrochemical degradation of p-nitrophenol were initially investigated at the BDD anode in the presence of zero-valent iron (ZVI). The results showed that under acidic condition, the performance of BDD anode system containing zero-valent iron (BDD-ZVI system) could be improved with the joint actions of electrochemical oxidation at the BDD anode (39.1%), Fenton's reaction (28.5%), oxidation–reduction at zero-valent iron (17.8%) and coagulation of iron hydroxides (14.6%). Moreover, it was found that under alkaline condition the performance of BDD-ZVI system was significantly enhanced, mainly due to the accelerated release of Fe(II) ions from ZVI and the enhanced oxidation of Fe(II) ions. The dissolved oxygen concentration was significantly reduced by reduction at the cathode, and consequently zero-valent iron corroded to Fe(II) ions in anaerobic highly alkaline environments. Furthermore, the oxidation of released Fe(II) ions to Fe(III) ions and high-valent iron species (e.g., FeO2+, FeO42−) was enhanced by direct electrochemical oxidation at BDD anode.

  7. Electrochemical Imprinted Polycrystalline Nickel-Nickel Oxide Half-Nanotube-Modified Boron-Doped Diamond Electrode for the Detection of L-Serine.

    Science.gov (United States)

    Dai, Wei; Li, Hongji; Li, Mingji; Li, Cuiping; Wu, Xiaoguo; Yang, Baohe

    2015-10-21

    This paper presents a novel and versatile method for the fabrication of half nanotubes (HNTs) using a flexible template-based nanofabrication method denoted as electrochemical imprinting. With use of this method, polycrystalline nickel and nickel(II) oxide (Ni-NiO) HNTs were synthesized using pulsed electrodeposition to transfer Ni, deposited by radio frequency magnetron sputtering on a porous polytetrafluoroethylene template, onto a boron-doped diamond (BDD) film. The Ni-NiO HNTs exhibited semicircular profiles along their entire lengths, with outer diameters of 50-120 nm and inner diameters of 20-50 nm. The HNT walls were formed of Ni and NiO nanoparticles. A biosensor for the detection of L-serine was fabricated using a BDD electrode modified with Ni-NiO HNTs, and the device demonstrated satisfactory analytical performance with high sensitivity (0.33 μA μM(-1)) and a low limit of detection (0.1 μM). The biosensor also exhibited very good reproducibility and stability, as well as a high anti-interference ability against amino acids such as L-leucine, L-tryptophan, L-cysteine, L-phenylalanine, L-arginine, and L-lysine.

  8. Demonstration Of Electrochemical Oxidation Of Oils Using Boron-Doped Diamond Electrodes And Its Potential Role In The Disposal Of Radioactively Contaminated Waste Lubricants

    International Nuclear Information System (INIS)

    Electrochemical oxidation using a boron-doped diamond (BDD) anode is being investigated as a possible method for treating radiologically-contaminated oils. It has the potential to oxidise oils to carbon dioxide and water, and it would be particularly beneficial for oils contaminated with plutonium. It was found that simultaneous application of sonication and electro-oxidation produced and maintained an oil emulsion, so enabling its oxidation. This treatment was shown to be effective with 3 different oils: an unused hydraulic oil, an unused vacuum pump oil and a waste used machine tool oil, although the addition of a small amount of surfactant was required for the effective emulsification and oxidation of the vacuum pump oil. Essentially complete oxidation of the hydraulic oil in the absence of other organic material was demonstrated. The rate of oxidation appeared to be limited by the applied current when the concentration of oil was high and the current was low. Similarly, it was limited by the oil concentration when the concentration of oil was low and the current was relatively high. The required scale-up from a laboratory electrochemical cell is estimated to be 10,000 fold, which could entail a cell with a total BDD surface area of 3 m2, drawing a current of about 2000 A. It is anticipated that it should be possible to minimise the size of the cell by optimisation during the design of the prototype equipment. (authors)

  9. Molecular Signature of Pseudomonas aeruginosa with Simultaneous Nanomolar Detection of Quorum Sensing Signaling Molecules at a Boron-Doped Diamond Electrode

    Science.gov (United States)

    Buzid, Alyah; Shang, Fengjun; Reen, F. Jerry; Muimhneacháin, Eoin Ó; Clarke, Sarah L.; Zhou, Lin; Luong, John H. T.; O’Gara, Fergal; McGlacken, Gerard P.; Glennon, Jeremy D.

    2016-01-01

    Electroanalysis was performed using a boron-doped diamond (BDD) electrode for the simultaneous detection of 2-heptyl-3-hydroxy-4-quinolone (PQS), 2-heptyl-4-hydroxyquinoline (HHQ) and pyocyanin (PYO). PQS and its precursor HHQ are two important signal molecules produced by Pseudomonas aeruginosa, while PYO is a redox active toxin involved in virulence and pathogenesis. This Gram-negative and opportunistic human pathogen is associated with a hospital-acquired infection particularly in patients with compromised immunity and is the primary cause of morbidity and mortality in cystic fibrosis (CF) patients. Early detection is crucial in the clinical management of this pathogen, with established infections entering a biofilm lifestyle that is refractory to conventional antibiotic therapies. Herein, a detection procedure was optimized and proven for the simultaneous detection of PYO, HHQ and PQS in standard mixtures, biological samples, and P. aeruginosa spiked CF sputum samples with remarkable sensitivity, down to nanomolar levels. Differential pulse voltammetry (DPV) scans were also applicable for monitoring the production of PYO, HHQ and PQS in P. aeruginosa PA14 over 8 h of cultivation. The simultaneous detection of these three compounds represents a molecular signature specific to this pathogen. PMID:27427496

  10. Direct electrochemistry of Shewanella loihica PV-4 on gold nanoparticles-modified boron-doped diamond electrodes fabricated by layer-by-layer technique.

    Science.gov (United States)

    Wu, Wenguo; Xie, Ronggang; Bai, Linling; Tang, Zuming; Gu, Zhongze

    2012-05-01

    Microbial Fuel Cells (MFCs) are robust devices capable of taping biological energy, converting pollutants into electricity through renewable biomass. The fabrication of nanostructured electrodes with good bio- and electrochemical activity, play a profound role in promoting power generation of MFCs. Au nanoparticles (AuNPs)-modified Boron-Doped Diamond (BDD) electrodes are fabricated by layer-by-layer (LBL) self-assembly technique and used for the direct electrochemistry of Shewanella loihica PV-4 in an electrochemical cell. Experimental results show that the peak current densities generated on the Au/PAH multilayer-modified BDD electrodes increased from 1.25 to 2.93 microA/cm(-2) as the layer increased from 0 to 6. Different cell morphologies of S. loihica PV-4 were also observed on the electrodes and the highest density of cells was attached on the (Au/PAH)6/BDD electrode with well-formed three-dimensional nanostructure. The electrochemistry of S. loihica PV-4 was enhanced on the (Au/PAH)4/BDD electrode due to the appropriate amount of AuNPsand thickness of PAH layer.

  11. In situ control of local pH using a boron doped diamond ring disk electrode: optimizing heavy metal (mercury) detection.

    Science.gov (United States)

    Read, Tania L; Bitziou, Eleni; Joseph, Maxim B; Macpherson, Julie V

    2014-01-01

    A novel electrochemical approach to modifying aqueous solution pH in the vicinity of a detector electrode in order to optimize the electrochemical measurement signal is described. A ring disk electrode was employed where electrochemical decomposition of water on the ring was used to generate a flux of protons which adjusts the local pH controllably and quantifiably at the disk. Boron doped diamond (BDD) functioned as the electrode material given the stability of this electrode surface especially when applying high potentials (to electrolyze water) for significant periods of time. A pH sensitive iridium oxide electrode electrodeposited on the disk electrode demonstrated that applied positive currents on the BDD ring, up to +50 μA, resulted in a local pH decrease of over 4 orders of magnitude, which remained stable over the measurement time of 600 s. pH generation experiments were found to be in close agreement with finite element simulations. The dual electrode arrangement was used to significantly improve the stripping peak signature for Hg in close to neutral conditions by the generation of pH = 2.0, locally. With the ability to create a localized pH change electrochemically in the vicinity of the detector electrode, this system could provide a simple method for optimized analysis at the source, e.g., river and sea waters. PMID:24321045

  12. Degradation of the beta-blocker propranolol by electrochemical advanced oxidation processes based on Fenton's reaction chemistry using a boron-doped diamond anode

    Energy Technology Data Exchange (ETDEWEB)

    Isarain-Chavez, Eloy; Rodriguez, Rosa Maria; Garrido, Jose Antonio; Arias, Conchita; Centellas, Francesc; Cabot, Pere Lluis [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Brillas, Enric, E-mail: brillas@ub.ed [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain)

    2010-12-15

    The electro-Fenton (EF) and photoelectro-Fenton (PEF) degradation of solutions of the beta-blocker propranolol hydrochloride with 0.5 mmol dm{sup -3} Fe{sup 2+} at pH 3.0 has been studied using a single cell with a boron-doped diamond (BDD) anode and an air diffusion cathode (ADE) for H{sub 2}O{sub 2} electrogeneration and a combined cell containing the above BDD/ADE pair coupled in parallel to a Pt/carbon felt (CF) cell. This naphthalene derivative can be mineralized by both methods with a BDD anode. Almost overall mineralization is attained for the PEF treatments, more rapidly with the combined system due to the generation of higher amounts of hydroxyl radical from Fenton's reaction by the continuous Fe{sup 2+} regeneration at the CF cathode, accelerating the oxidation of organics to Fe(III)-carboxylate complexes that are more quickly photolyzed by UVA light. The homologous EF processes are less potent giving partial mineralization. The effect of current density, pH and Fe{sup 2+} and drug concentrations on the oxidation power of PEF process in combined cell is examined. Propranolol decay follows a pseudo first-order reaction in most cases. Aromatic intermediates such as 1-naphthol and phthalic acid and generated carboxylic acids such as maleic, formic, oxalic and oxamic are detected and quantified by high-performance liquid chromatography. The chloride ions present in the starting solution are slowly oxidized at the BDD anode. In PEF treatments, all initial N of propranolol is completely transformed into inorganic ions, with predominance of NH{sub 4}{sup +} over NO{sub 3}{sup -} ion.

  13. Degradation of 4,6-dinitro-o-cresol from water by anodic oxidation with a boron-doped diamond electrode

    Energy Technology Data Exchange (ETDEWEB)

    Flox, Cristina [Laboratori de Ciencia i Tecnologia Electroquimica de Materials, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Garrido, Jose Antonio [Laboratori de Ciencia i Tecnologia Electroquimica de Materials, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Rodriguez, Rosa Maria [Laboratori de Ciencia i Tecnologia Electroquimica de Materials, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Centellas, Francesc [Laboratori de Ciencia i Tecnologia Electroquimica de Materials, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Cabot, Pere-Lluis [Laboratori de Ciencia i Tecnologia Electroquimica de Materials, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Arias, Conchita [Laboratori de Ciencia i Tecnologia Electroquimica de Materials, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Brillas, Enric [Laboratori de Ciencia i Tecnologia Electroquimica de Materials, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain)]. E-mail: brillas@ub.edu

    2005-06-10

    Anodic oxidation of 4,6-dinitro-o-cresol (DNOC) has been studied in a cell of 100 ml with a boron-doped diamond anode and a graphite cathode, both of 3-cm{sup 2} area. Solutions containing up to approximately 240 mg l{sup -1} of compound in the pH range 2.0-12.0 have been treated at 100, 300 and 450 mA between 15 and 50 deg C. Total mineralization is always achieved due to the great amount of hydroxyl radical ({center_dot}OH) produced as oxidant on the anode surface. Total organic carbon is more rapidly removed in acid medium, being the optimum pH 3.0. The degradation rate increases when temperature, current and DNOC concentration increase. However, at 100 mA depollution becomes more effective from 71 mg l{sup -1} of initial pollutant. A pseudo first-order kinetics for DNOC decay is always found by reversed-phase chromatography, with a rate constant practically independent of pH, as expected if the same electroactive species is oxidized in all media. Ion-exclusion chromatography allowed the detection of oxalic acid as the ultimate carboxylic acid. The mineralization process leads to the complete release of NO{sub 3} {sup -} ions from the destruction of nitroderivative intermediates. These products are oxidized simultaneously with accumulated oxalic acid up to the end of electrolyses. Comparative treatment of the same solutions with a Pt anode yields a quite poor depollution because of the generation of much lower amounts of reactive {center_dot}OH on its surface.

  14. Investigation of the synergistic effects for p-nitrophenol mineralization by a combined process of ozonation and electrolysis using a boron-doped diamond anode

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Cuicui [School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing 100084 (China); Yuan, Shi [School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing 100084 (China); Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Li, Xiang; Wang, Huijiao; Bakheet, Belal [School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing 100084 (China); Komarneni, Sridhar [Department of Ecosystem Science and Management and Material Research Institute, 205 MRL Building, The Pennsylvania State University, University Park, PA 16802 (United States); Wang, Yujue, E-mail: wangyujue@tsinghua.edu.cn [School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing 100084 (China); Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China)

    2014-09-15

    Graphical abstract: - Highlights: • Combining electrolysis with ozonation greatly enhances nitrophenol mineralization. • O{sub 3} can rapidly degrade nitrophenol to carboxylic acids in the bulk solution. • Carboxylic acids can be mineralized by ·OH generated from multiple sources in the electrolysis-O{sub 3} process. • Electrolysis and ozonation can compensate for each other's weakness on pollutant degradation. - Abstract: Electrolysis and ozonation are two commonly used technologies for treating wastewaters contaminated with nitrophenol pollutants. However, they are often handicapped by their slow kinetics and low yields of total organic carbon (TOC) mineralization. To improve TOC mineralization efficiency, we combined electrolysis using a boron-doped diamond (BDD) anode with ozonation (electrolysis-O{sub 3}) to treat a p-nitrophenol (PNP) aqueous solution. Up to 91% TOC was removed after 60 min of the electrolysis-O{sub 3} process. In comparison, only 20 and 44% TOC was respectively removed by individual electrolysis and ozonation treatment conducted under similar reaction conditions. The result indicates that when electrolysis and ozonation are applied simultaneously, they have a significant synergy for PNP mineralization. This synergy can be mainly attributed to (i) the rapid degradation of PNP to carboxylic acids (e.g., oxalic acid and acetic acid) by O{sub 3}, which would otherwise take a much longer time by electrolysis alone, and (ii) the effective mineralization of the ozone-refractory carboxylic acids to CO{sub 2} by ·OH generated from multiple sources in the electrolysis-O{sub 3} system. The result suggests that combining electrolysis with ozonation can provide a simple and effective way to mutually compensate the limitations of the two processes for degradation of phenolic pollutants.

  15. AFM studies and electrochemical characterization of boron-doped diamond surfaces modified with metal oxides by the sol-gel method

    International Nuclear Information System (INIS)

    Continuing previous investigations, direct surface modifications of boron-doped diamond (BDD) electrodes with metal oxides (PtOx, RuO2, IrO2 and PbO2) and with some mixed composites were carried out by the Sol-Gel technique. The materials were studied by atomic force microscopy (AFM) to determine their surface topologies and by electrochemical techniques to establish the catalytic activity towards the oxygen evolution reaction (OER) and also, for the PtOx and PtOx- RuO2 composites, the ethanol oxidation reactions in acid media. The stability of PtOx coating covered by a Nafiontrade mark film was also tested by long-term operation. The AFM results indicated sites of heterogeneous deposition and the electrochemical studies demonstrated that the active surface area changed considerably with the proposed method of modification. The IrO2/BDD electrode showed the best performance to the OER with the onset of the oxidation current at ∼1.4 V, a value 200 mV lower than for the PtOx/BDD electrode. The enhanced stability of PtOx/BDD electrodes achieved by the application of a Nafiontrade mark film and already reported in acid media was further proved using the ethanol oxidation reaction. Only a small loss of activity (6%) was observed after 4-hours electrolysis while one-thousand voltammetric cycles left the surface practically unchanged. In addition, preliminary studies for the same reaction on PtOx/BDD and PtOx-RuO2/ BDD electrodes demonstrated the excellent activity of these mixed Sol-Gel coatings on the BDD surface and the possibility of further investigations for practical applications. (author)

  16. 掺硼金刚石膜电极处理医院废水的研究%Study on Hospital Wastewater using Boron-doped Diamond Electrode

    Institute of Scientific and Technical Information of China (English)

    于鲁冀; 孔德芳; 王震; 杨强

    2013-01-01

    通过研究自制电解槽,利用掺硼金刚石膜电极(BDD)对医疗废水进行消毒实验研究.实验研究了电流密度、消毒时间及Cl-浓度对消毒效果的影响.实验结果表明:电流密度越大,消毒效果越好;消毒接触时间越长,消毒效果越好;Cl-浓度对消毒效果影响显著,医疗废水C1-质量浓度达到200 mg/L以上,消毒接触时间≥9s,出水即可满足GB 18466-2005《医疗机构水污染物排放标准》粪大肠茵群数均不得超过500 MPN/L.%Study on the disinfection effect of hospital wastewater using the boron-doped diamond film electrode (BDD) in the self-electrolyzer was carried out. The disinfection effect of current density, disinfection time and the concentration of CV were studied in this experiment. The results showed that the greater the electric current density is, the better disinfection effect will be. The longer the contact time is,the better disinfection effect will be. The concentration of Cl- is significant on the disinfection effect. When the concentration of Cl- in hospital wastewater is more than 200 mg/L as well as the disinfection contact time is more than 9 s,the effluent could meet the requirement of the Medical Institutions Sewage Discharge Standard (GB 18466—2005) in which the value of fecal coliform should be no more than 500 MPN/L.

  17. Diclofenac on boron-doped diamond electrode: from electroanalytical determination to prediction of the electrooxidation mechanism with HPLC-ESI/HRMS and computational simulations.

    Science.gov (United States)

    Lucas, Francisco Willian de S; Mascaro, Lucia H; Fill, Taicia P; Rodrigues-Filho, Edson; Franco-Junior, Edison; Homem-de-Mello, Paula; de Lima-Neto, Pedro; Correia, Adriana N

    2014-05-20

    Using square-wave voltammetry coupled to the boron-doped diamond electrode (BDDE), it was possible to develop an analytical methodology for identification and quantification of diclofenac (DCL) in tablets and synthetic urine. The electroanalytical procedure was validated, with results being statistically equal to those obtained by chromatographic standard method, showing linear range of 4.94 × 10(-7) to 4.43 × 10(-6) mol L(-1), detection limit of 1.15 × 10(-7) mol L(-1), quantification limit of 3.85 × 10(-7) mol L(-1), repeatability of 3.05% (n = 10), and reproducibility of 1.27% (n = 5). The association of electrochemical techniques with UV-vis spectroscopy, computational simulations and HPLC-ESI/HRMS led us to conclude that the electrooxidation of DCL on the BDDE involved two electrons and two protons, where the products are colorful and easily hydrolyzable dimers. Density functional theory calculations allowed to evaluate the stability of dimers A, B, and C, suggesting dimer C was more stable than the other two proposed structures, ca. 4 kcal mol(-1). The comparison of the dimers stabilities with the stabilities of the molecular ions observed in the MS, the compounds that showed retention time (RT) of 15.53, 21.44, and 22.39 min were identified as the dimers B, C, and A, respectively. Corroborating the observed chromatographic profile, dimer B had a dipole moment almost twice higher than that of dimers A and C. As expected, dimer B has really shorter RT than dimers A and C. The majority dimer was the A (71%) and the C (19.8%) should be the minority dimer. However, the minority was the dimer B, which was formed in the proportion of 9.2%. This inversion between the formation proportion of dimer B and dimer C can be explained by preferential conformation of the intermediaries (cation-radicals) on the surface.

  18. Degradation of 4,6-dinitro-o-cresol from water by anodic oxidation with a boron-doped diamond electrode

    International Nuclear Information System (INIS)

    Anodic oxidation of 4,6-dinitro-o-cresol (DNOC) has been studied in a cell of 100 ml with a boron-doped diamond anode and a graphite cathode, both of 3-cm2 area. Solutions containing up to approximately 240 mg l-1 of compound in the pH range 2.0-12.0 have been treated at 100, 300 and 450 mA between 15 and 50 deg C. Total mineralization is always achieved due to the great amount of hydroxyl radical (·OH) produced as oxidant on the anode surface. Total organic carbon is more rapidly removed in acid medium, being the optimum pH 3.0. The degradation rate increases when temperature, current and DNOC concentration increase. However, at 100 mA depollution becomes more effective from 71 mg l-1 of initial pollutant. A pseudo first-order kinetics for DNOC decay is always found by reversed-phase chromatography, with a rate constant practically independent of pH, as expected if the same electroactive species is oxidized in all media. Ion-exclusion chromatography allowed the detection of oxalic acid as the ultimate carboxylic acid. The mineralization process leads to the complete release of NO3- ions from the destruction of nitroderivative intermediates. These products are oxidized simultaneously with accumulated oxalic acid up to the end of electrolyses. Comparative treatment of the same solutions with a Pt anode yields a quite poor depollution because of the generation of much lower amounts of reactive ·OH on its surface

  19. Boron doping a semiconductor particle

    Science.gov (United States)

    Stevens, Gary Don; Reynolds, Jeffrey Scott; Brown, Louanne Kay

    1998-06-09

    A method (10,30) of boron doping a semiconductor particle using boric acid to obtain a p-type doped particle. Either silicon spheres or silicon powder is mixed with a diluted solution of boric acid having a predetermined concentration. The spheres are dried (16), with the boron film then being driven (18) into the sphere. A melt procedure mixes the driven boron uniformly throughout the sphere. In the case of silicon powder, the powder is metered out (38) into piles and melted/fused (40) with an optical furnace. Both processes obtain a p-type doped silicon sphere with desired resistivity. Boric acid is not a restricted chemical, is inexpensive, and does not pose any special shipping, handling, or disposal requirements.

  20. Concentration and electrode material dependence of the voltammetric response of iodide on platinum, glassy carbon and boron-doped diamond in the room temperature ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide

    International Nuclear Information System (INIS)

    The electro-oxidation of iodide has been investigated as a function of concentration using steady-state microelectrode voltammetry, transient cyclic voltammetry and linear-sweep semi-integral voltammetry on platinum, glassy carbon and boron-doped diamond electrodes in the room temperature ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide. Two oxidation processes are observed on all of the investigated electrode materials, with the first being assigned to the oxidation of iodide to triiodide (confirmed by UV/visible spectroscopy) and the second being attributed to the oxidation of triiodide to iodine. Iodide oxidation is kinetically more facile on platinum compared to glassy carbon or boron-doped diamond. At elevated bulk iodide concentrations, the nucleation and growth of sparingly soluble electrogenerated iodine at the electrode surface was observed and imaged in situ using optical microscopy. The diffusion coefficient of iodide was determined to be 2.59 (±0.04) × 10−7 cm2 s−1 and independent of the bulk concentration of iodide. The steady-state iodide oxidation current measured at a platinum microelectrode was found to be a linear function of iodide concentration, as expected if there are no contributions from non-Stokesian mass-transport processes (electron hopping and/or Grotthuss-type exchange) under the investigated conditions

  1. Evolution of Diamond Crystal Shape with Boron Concentration during CVD Growth

    Science.gov (United States)

    Issaoui, R.; Silva, F.; Tallaire, A.; Mille, V.; Achard, J.; Gicquel, A.

    2010-11-01

    Homoepitaxially grown boron-doped diamond films have been extensively studied for many years, in particular for the development of power-electronic devices. Coplanar structures have already been fabricated and characterized but, in such structures, the current is limited by a high series resistance. A vertical component could allow overcoming this issue but this requires that thick heavily boron-doped diamond crystals with a large usable top surface are grown. In this paper we used a 3D geometrical model in order to study the evolution of the crystal shape of thick diamond crystals as a function of boron doping. The growth parameters used in the model were determined by measuring the growth rate in different crystalline orientations. It was found that the addition of boron to the gas phase promotes the appearance of large {110} and {113} crystalline faces. {110} faces have a detrimental effect on the crystal since they can generate large stress and promote crystal break-up. The results predicted by the model are consistent with that obtained for a thick boron-doped diamond single crystal.

  2. Hydroxyl radical-related electrogenerated chemiluminescence reaction for a ruthenium tris(2,2')bipyridyl/co-reactants system at boron-doped diamond electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Honda, K. [Department of Chemistry and Earth Sciences, Faculty of Science Yamaguchi University, 1677-1 Yoshida, Yamaguchi-shi, Yamaguchi 753-8512 (Japan)]. E-mail: khonda@yamaguchi-u.ac.jp; Yamaguchi, Y. [Department of Chemistry and Earth Sciences, Faculty of Science Yamaguchi University, 1677-1 Yoshida, Yamaguchi-shi, Yamaguchi 753-8512 (Japan); Yamanaka, Y. [Department of Chemistry and Earth Sciences, Faculty of Science Yamaguchi University, 1677-1 Yoshida, Yamaguchi-shi, Yamaguchi 753-8512 (Japan); Yoshimatsu, M. [Department of Chemistry and Earth Sciences, Faculty of Science Yamaguchi University, 1677-1 Yoshida, Yamaguchi-shi, Yamaguchi 753-8512 (Japan); Fukuda, Y. [Department of Chemistry and Earth Sciences, Faculty of Science Yamaguchi University, 1677-1 Yoshida, Yamaguchi-shi, Yamaguchi 753-8512 (Japan); Fujishima, A. [Kanagawa Academy of Science and Technology (KAST), 3-2-1, Sakato, Takastu-ku, Kawasaki-shi, Kanagawa 213-0012 (Japan)

    2005-11-01

    An electrogenerated chemiluminescence (ECL) reaction of the Ru(bpy){sub 3} {sup 2+} (2,2'-bipyridyl, bpy)/co-reactant system in the extremely high-potential region (over 2.6 V versus Ag/AgCl) was probed using a boron-doped diamond (BDD) electrode. At the BDD electrode, three ECL waves (1.25, 2.30 and 3.72 V) were observed in cyclic voltammograms for 20 mM ascorbic acid (AA). For the ECL peaks observed at 1.25 V corresponding to the oxidation potential for Ru(bpy){sub 3} {sup 2+} (1.15 V), the light intensities and current densities were found to depend on the square root of the AA concentration. This suggests that AA oxidation, followed by the formation of the reducing radical that is necessary for generating the excited state of Ru(bpy){sub 3} {sup 2+*} occurred through homogeneous electron-transfer between Ru(bpy){sub 3} {sup 3+} and the AA species. However, for the ECL peaks at 2.30 V, the current densities and light intensities linearly increased with increasing AA concentration, suggesting that the reducing radical was formed through the direct oxidation at the electrode surface. The ECL reaction at 3.72 V was observed only at the BDD electrode and not at other electrodes. The onset potentials for the light intensity were approximately 2.6 V, independently of the type of the co-reactants (e.g. 2-propanol and AA). The peak potentials exhibited linear relation with the co-reactant concentration. In the analysis of the ECL intensity for various co-reactants (alcohols) that show different reactivity for the hydrogen abstraction reaction, the order of the light intensities at the peaks for alcohols was found to be consistent with that for the rate constants of the hydrogen abstraction reaction. These results indicate that the co-reactant radical was formed through the hydrogen abstraction reaction with the hydroxyl radical (HO{center_dot}) generated during the oxygen evolution reaction.

  3. Ionization equilibrium at the transition from valence-band to acceptor-band migration of holes in boron-doped diamond

    Science.gov (United States)

    Poklonski, N. A.; Vyrko, S. A.; Poklonskaya, O. N.; Kovalev, A. I.; Zabrodskii, A. G.

    2016-06-01

    A quasi-classical model of ionization equilibrium in the p-type diamond between hydrogen-like acceptors (boron atoms which substitute carbon atoms in the crystal lattice) and holes in the valence band (v-band) is proposed. The model is applicable on the insulator side of the insulator-metal concentration phase transition (Mott transition) in p-Dia:B crystals. The densities of the spatial distributions of impurity atoms (acceptors and donors) and of holes in the crystal are considered to be Poissonian, and the fluctuations of their electrostatic potential energy are considered to be Gaussian. The model accounts for the decrease in thermal ionization energy of boron atoms with increasing concentration, as well as for electrostatic fluctuations due to the Coulomb interaction limited to two nearest point charges (impurity ions and holes). The mobility edge of holes in the v-band is assumed to be equal to the sum of the threshold energy for diffusion percolation and the exchange energy of the holes. On the basis of the virial theorem, the temperature Tj is determined, in the vicinity of which the dc band-like conductivity of holes in the v-band is approximately equal to the hopping conductivity of holes via the boron atoms. For compensation ratio (hydrogen-like donor to acceptor concentration ratio) K ≈ 0.15 and temperature Tj, the concentration of "free" holes in the v-band and their jumping (turbulent) drift mobility are calculated. Dependence of the differential energy of thermal ionization of boron atoms (at the temperature 3Tj/2) as a function of their concentration N is calculated. The estimates of the extrapolated into the temperature region close to Tj hopping drift mobility of holes hopping from the boron atoms in the charge states (0) to the boron atoms in the charge states (-1) are given. Calculations based on the model show good agreement with electrical conductivity and Hall effect measurements for p-type diamond with boron atom concentrations in the

  4. Efficiency and stability of spectral sensitization of boron-doped-diamond electrodes through covalent anchoring of a donor-acceptor organic chromophore (P1).

    Science.gov (United States)

    Krysova, Hana; Barton, Jan; Petrak, Vaclav; Jurok, Radek; Kuchar, Martin; Cigler, Petr; Kavan, Ladislav

    2016-06-28

    A novel procedure is developed for chemical modification of H-terminated B-doped diamond surfaces with a donor-π-bridge-acceptor molecule (P1). A cathodic photocurrent near 1 μA cm(-2) flows under 1 Sun (AM 1.5) illumination at the interface between the diamond electrode and aqueous electrolyte solution containing dimethylviologen (electron mediator). The efficiency of this new electrode outperforms that of the non-covalently modified diamond with the same dye. The found external quantum efficiency of the P1-sensitized diamond is not far from that of the flat titania electrode sensitized by a standard organometallic dye used in solar cells. However, the P1 dye, both pure and diamond-anchored, shows significant instability during illumination by solar light. The degradation is a two-stage process in which the initially photo-generated products further decompose in complicated dark reactions. These findings need to be taken into account for optimization of organic chromophores for solar cells in general. PMID:27264474

  5. Architecting boron nanostructure on the diamond particle surface

    Energy Technology Data Exchange (ETDEWEB)

    Bai, H.; Dai, D.; Yu, J.H. [Key Laboratory of Marine New Materials and Application Technology, Ningbo Institute of Materials Technologies and Engineering, Chinese Academy of Sciences, 519 Zhuangshi Road, Zhenhai, Ningbo 315201 (China); Nishimura, K. [Key Laboratory of Marine New Materials and Application Technology, Ningbo Institute of Materials Technologies and Engineering, Chinese Academy of Sciences, 519 Zhuangshi Road, Zhenhai, Ningbo 315201 (China); Kochi FEL Co. Ltd., 3-1,Shinonome-cho, Kochi-shi 780-0805 (Japan); Sasaoka, S. [Kochi FEL Co. Ltd., 3-1,Shinonome-cho, Kochi-shi 780-0805 (Japan); Jiang, N., E-mail: jiangnan@nimte.ac.cn [Key Laboratory of Marine New Materials and Application Technology, Ningbo Institute of Materials Technologies and Engineering, Chinese Academy of Sciences, 519 Zhuangshi Road, Zhenhai, Ningbo 315201 (China)

    2014-02-15

    The present study provides an efficient approach for nano-functionalization of diamond powders. Boron nanostructure can be grown on diamond particle entire surface by a simple heat-treatment process. After treatment, various boron nanoforms were grown on the diamond particle surface at different processing temperature. High-density boron nanowires (BNWs) grow on the diamond particle entire surface at 1333 K, while nanopillars cover diamond powders when the heat treatment process is performed at 1393 K. The influence of the pretreatment temperature on the microstructure and thermal conductivity of Cu/diamond composites were investigated. Cu/diamond composites with high thermal conductivity of 670 W (m K){sup −1} was obtained, which was achieved by the formation of large number of nanowires and nanopillars on the diamond particle surface.

  6. Doping level influence on chemical surface of diamond electrodes

    Science.gov (United States)

    Azevedo, A. F.; Baldan, M. R.; Ferreira, N. G.

    2013-04-01

    The modification of surface bond termination promoted by the doping level on diamond electrodes is analyzed. The films were prepared by hot filament chemical vapor deposition technique using the standard mixture of H2/CH4 with an extra H2 flux passing through a bubbler containing different concentrations of B2O3 dissolved in methanol. Diamond morphology and quality were characterized by scanning electron microscopy and Raman scattering spectroscopy techniques while the changes in film surfaces were analyzed by contact angle, cyclic voltammetry and synchrotron X-ray photoelectron spectroscopy (XPS). The boron-doped diamond (BDD) films hydrophobicity, reversibility, and work potential window characteristics were related to their physical properties and chemical surface, as a function of the doping level. From the Mott-Schottky plots (MSP) and XPS analyzes, for the lightly (1018 cm-3) and highly (1020 cm-3) BDD films, the relationship between the BDD electrochemical responses and their surface bond terminations is discussed.

  7. 不同浓度硼掺杂金刚石薄膜的场发射性能的研究%Enhanced Field Emission Characteristics of Boron Doped Diamond Films Grown by Microwave Plasma Assisted Chemical Vapor Deposition

    Institute of Scientific and Technical Information of China (English)

    石晓林

    2013-01-01

      利用微波等离子体化学气相淀积法(MPCVD),在硅基片上合成硼掺杂金刚石薄膜。研究B2O3从1000~5000 ppm不同浓度对场发射性能影响。随硼浓度地增加,纳米金刚石(NCD)薄膜的场发射性能得到改善。且场发射性能的增强归功于更好的电导率和金刚石薄膜的纳米特性。%s:Boron doped diamond films were synthesized on silicon substrates by MPCVD technique.The effect of B2O3concentration varied from 1000to5000ppm on the field emission characteristics was examined.The field emission properties of NCD films were observed to improve upon increasing boron concentration.The enhanced field emission properties are attributed to the better electrical conductivity coupled with the nanometric features of the diamond films.

  8. Polarization complex-plane plot of impedance for two-stage charge-transfer reaction complicated with an intermediate adsorption (by example of benzene oxidation at boron-doped diamond electrode)

    International Nuclear Information System (INIS)

    Polarization complex-plane plot of impedance for two-stage anodic reaction with partial charge transfer, complicated with an intermediate adsorption, is theoretically analyzed. The case of linear coverage dependence of the oxidation rate and linear potential dependence of the effective number of electrons involved in each stage, hence, quadratic potential dependence of the activation energies is considered. The result of the modeling agrees qualitatively with experimental data on benzene oxidation at boron-doped diamond electrode. The using of the partial charge transfer concept allowed revealing fine effects of the organics oxidation, which are ascribed to adsorption, in particular, emergence of a loop in the polarization complex-plane plot of impedance

  9. Superconductivity in heavily boron-doped silicon carbide

    Directory of Open Access Journals (Sweden)

    Markus Kriener, Takahiro Muranaka, Junya Kato, Zhi-An Ren, Jun Akimitsu and Yoshiteru Maeno

    2008-01-01

    Full Text Available The discoveries of superconductivity in heavily boron-doped diamond in 2004 and silicon in 2006 have renewed the interest in the superconducting state of semiconductors. Charge-carrier doping of wide-gap semiconductors leads to a metallic phase from which upon further doping superconductivity can emerge. Recently, we discovered superconductivity in a closely related system: heavily boron-doped silicon carbide. The sample used for that study consisted of cubic and hexagonal SiC phase fractions and hence this led to the question which of them participated in the superconductivity. Here we studied a hexagonal SiC sample, free from cubic SiC phase by means of x-ray diffraction, resistivity, and ac susceptibility.

  10. Electrochemical detection of biapenem by a boron-doped diamond nanorod electrode%硼掺杂金刚石纳米棒电极对比阿培南的电化学检测研究

    Institute of Scientific and Technical Information of China (English)

    钟萍; 罗代兵; 任雁; 只金芳

    2011-01-01

    Biapenem is a new parenteral carbapenem that has antibacterial activity against a wide range of Gram-positive and -negative bacteria. Electroanalysis of biapenem and was made on a boron-doped diamond nanorod(BDDN ) electrode compared with a planar boron-doped diamond (BDD) electrode under the same conditions. The detection range of the BDDN electrode is wider and the sensitivity(0.038μ,A μM-1 )is higher than that of the BDD electrode(0.028μAμM-1 ). The BDDN electrode displays an amplified response than the flat BDD electrode. The BDDN electrode exhibits excellent electrochemical performance due to its higher e-lectro-active surface area and special nanostructures.%在自制的硅纳米线上采用热丝化学气相沉积方法制备了硼掺杂金刚石纳米棒电极.采用循环伏安及计时电流方法测定了在磷酸缓冲溶液中的药物比阿培南的浓度,灵敏度达到0.038μA μM-1较相同条件下制备得到的普通硼掺杂金刚石电极(0.028μA μM-1)相比有所提高.该纳米棒电极由于特殊的表面形貌,较普通硼掺杂金刚石电极表现出更优异的电化学检测性能.

  11. Spectroscopic ellipsometry of homoepitaxial diamond multilayers and delta-doped structures

    Energy Technology Data Exchange (ETDEWEB)

    Bousquet, J.; Chicot, G.; Eon, D.; Bustarret, E. [Univ. Grenoble Alpes, Inst. NEEL, F-38042 Grenoble (France); CNRS, Inst. NEEL, F-38042 Grenoble (France)

    2014-01-13

    The optimization of diamond-based unipolar electronic devices such as pseudo-vertical Schottky diodes or delta-doped field effect transistors relies in part on the sequential growth of nominally undoped (p{sup –}) and heavily boron doped (p{sup ++}) layers with well-controlled thicknesses and steep interfaces. Optical ellipsometry offers a swift and contactless method to characterize the thickness, roughness, and electronic properties of semiconducting and metallic diamond layers. We report ellipsometric studies carried out on delta-doped structures and other epitaxial multilayers with various boron concentrations and thicknesses (down to the nanometer range). The results are compared with Secondary Ion Mass Spectroscopy and transport measurements.

  12. Spectroscopic ellipsometry of homoepitaxial diamond multilayers and delta-doped structures

    International Nuclear Information System (INIS)

    The optimization of diamond-based unipolar electronic devices such as pseudo-vertical Schottky diodes or delta-doped field effect transistors relies in part on the sequential growth of nominally undoped (p–) and heavily boron doped (p++) layers with well-controlled thicknesses and steep interfaces. Optical ellipsometry offers a swift and contactless method to characterize the thickness, roughness, and electronic properties of semiconducting and metallic diamond layers. We report ellipsometric studies carried out on delta-doped structures and other epitaxial multilayers with various boron concentrations and thicknesses (down to the nanometer range). The results are compared with Secondary Ion Mass Spectroscopy and transport measurements

  13. Highly-focused boron implantation in diamond and imaging using the nuclear reaction 11B(p, α)8Be

    Science.gov (United States)

    Ynsa, M. D.; Ramos, M. A.; Skukan, N.; Torres-Costa, V.; Jakšić, M.

    2015-04-01

    Diamond is an especially attractive material because of its gemological value as well as its unique mechanical, chemical and physical properties. One of these properties is that boron-doped diamond is an electrically p-type semiconducting material at practically any boron concentration. This property makes it possible to use diamonds for multiple industrial and technological applications. Boron can be incorporated into pure diamond by different techniques including ion implantation. Although typical energies used to dope diamond by ion implantation are about 100 keV, implantations have also been performed with energies above MeV. In this work CMAM microbeam setup has been used to demonstrate capability to implant boron with high energies. An 8 MeV boron beam with a size of about 5 × 3 μm2 and a beam current higher than 500 pA has been employed while controlling the beam position and fluence at all irradiated areas. The subsequent mapping of the implanted boron in diamond has been obtained using the strong and broad nuclear reaction 11B(p, α)8Be at Ep = 660 keV. This reaction has a high Q-value (8.59 MeV for α0 and 5.68 MeV for α1) and thus is almost interference-free. The sensitivity of the technique is studied in this work.

  14. 高温高压 Fe-Ni-C-B 系中含硼金刚石单晶合成机理研究(下)%Study of the Synthesis Mechanism of Boron-doped Diamond Monocrystal of HPHT Fe-Ni-C-B Series

    Institute of Scientific and Technical Information of China (English)

    李和胜; 李木森; 宫建红

    2015-01-01

    In order to research on the synthesis mechanism and growth mechanism of the boron-doped diamond, the boron-doped diamond monocrystal synthesised from the HPHT Fe-Ni-C-B Series and its surrounded metallic film have been systematically analysed through modern materials analysis technology.The result shows that the boron element added into the metal catalyzer has been dissolved into the surrounded metallic film as a metal-carbon-boron compound.Being as the direct carbon/boron source for the growth of the boron-doped diamond,it was catalysed by intermetallic phase and the acti-vated carbon/boron atoms were extracted and spreaded onto the surface of the growing di-amond monocrystal to promote the growth of the diamond.The boron-doped diamond grow in a layered growth model.The source for this type of growth during the early stage comes from two dimensional crystal nucleus and from dislocation during the late stage. The activated carbon/boron atoms spread onto the surface of the diamond monocrystal and are absorbed at the front end of the growth step and then transformed into part of the diamond monocrystal.As the step continues to expand,new growth step continues to de-velop on the newly grown crystal surface while the boron-doped diamond monocrystal grows in a layered stack-based pattern.%采用现代材料分析测试方法,通过对高温高压 Fe-Ni-C-B 系合成出的含硼金刚石单晶及其金属包覆膜进行系统分析和表征,探寻含硼金刚石合成机理及生长机制。研究发现,添加在金属触媒中的硼以金属-碳-硼化合物的形式溶入金属包覆膜,作为含硼金刚石生长的直接碳/硼源,经金属中间相的催化,析出活性碳/硼原子(团)扩散至正在生长的金刚石单晶表面,促进金刚石的生长。而含硼金刚石则以一种层状生长的方式长大,这种层状生长的台阶来源前期以二维晶核为主,后期则以位错为主。活性碳/硼原子(团)扩散到达金刚石

  15. 高温高压 Fe-Ni-C-B 系中含硼金刚石单晶合成机理研究(上)%Study of the Synthesis Mechanism of Boron-doped Diamond Monocrystal of HPHT Fe-Ni-C-B Series

    Institute of Scientific and Technical Information of China (English)

    李和胜; 李木森; 宫建红

    2014-01-01

    In order to research on the synthesis mechanism and growth mechanism of the boron-doped diamond, the boron-doped diamond monocrystal synthesised from the HPHT Fe-Ni-C-B Series and its surrounded metallic film have been systematically analysed through modern materials analysis technology.The result shows that the boron element added into the metal catalyzer has been dissolved into the surrounded metallic film as a metal-carbon-boron compound.Being as the direct carbon/boron source for the growth of the boron-doped diamond,it was catalysed by intermetallic phase and the acti-vated carbon/boron atoms were extracted and spreaded onto the surface of the growing di-amond monocrystal to promote the growth of the diamond.The boron-doped diamond grow in a layered growth model.The source for this type of growth during the early stage comes from two dimensional crystal nucleus and from dislocation during the late stage.The activated carbon/boron atoms spread onto the surface of the diamond monocrystal and are absorbed at the front end of the growth step and then transformed into part of the diamond monocrystal.As the step continues to expand,new growth step continues to de-velop on the newly grown crystal surface while the boron-doped diamond monocrystal grows in a layered stack-based pattern.%采用现代材料分析测试方法,通过对高温高压 Fe-Ni-C-B 系合成出的含硼金刚石单晶及其金属包覆膜进行系统分析和表征,探寻含硼金刚石合成机理及生长机制。研究发现,添加在金属触媒中的硼以金属-碳-硼化合物的形式溶入金属包覆膜,作为含硼金刚石生长的直接碳/硼源,经金属中间相的催化,析出活性碳/硼原子(团)扩散至正在生长的金刚石单晶表面,促进金刚石的生长。而含硼金刚石则以一种层状生长的方式长大,这种层状生长的台阶来源前期以二维晶核为主,后期则以位错为主。活性碳/硼原子(团)扩散到达金刚石

  16. Stabilization of boron carbide via silicon doping.

    Science.gov (United States)

    Proctor, J E; Bhakhri, V; Hao, R; Prior, T J; Scheler, T; Gregoryanz, E; Chhowalla, M; Giulani, F

    2015-01-14

    Boron carbide is one of the lightest and hardest ceramics, but its applications are limited by its poor stability against a partial phase separation into separate boron and carbon. Phase separation is observed under high non-hydrostatic stress (both static and dynamic), resulting in amorphization. The phase separation is thought to occur in just one of the many naturally occurring polytypes in the material, and this raises the possibility of doping the boron carbide to eliminate this polytype. In this work, we have synthesized boron carbide doped with silicon. We have conducted a series of characterizations (transmission electron microscopy, scanning electron microscopy, Raman spectroscopy and x-ray diffraction) on pure and silicon-doped boron carbide following static compression to 50 GPa non-hydrostatic pressure. We find that the level of amorphization under static non-hydrostatic pressure is drastically reduced by the silicon doping.

  17. Improved depth resolution of secondary ion mass spectrometry profiles in diamond: A quantitative analysis of the delta-doping

    Energy Technology Data Exchange (ETDEWEB)

    Fiori, Alexandre, E-mail: FIORI.Alexandre@nims.go.jp [National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044 (Japan); Institut Néel, CNRS and Université Joseph Fourier, BP 166, 38042 Grenoble Cedex 9 (France); Jomard, François [GEMaC, CNRS and Université Versailles St Quentin, 45 avenue des Etats-Unis, 78035 Versailles Cedex (France); Teraji, Tokuyuki [National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044 (Japan); Chicot, Gauthier; Bustarret, Etienne [Institut Néel, CNRS and Université Joseph Fourier, BP 166, 38042 Grenoble Cedex 9 (France)

    2014-04-30

    In this work, we used the depth resolution function (DRF) of the secondary ion mass spectrometry (SIMS) to deconvolve the boron depth profile of nanometer-thin embedded diamond layers. Thanks to an isotopic change within a thin layer, where carbon-12 ({sup 12}C) and carbon-13 ({sup 13}C) are substituted, the DRF was evaluated by a self-consistent algorithm. In a second step, this DRF was used to deconvolve the boron depth profile of a double delta-doped diamond analyzed under the same ion beam condition. The expected position, thickness, and boron concentration of the embedded layers were confirmed. This technique has enhanced the SIMS performance, and the depth resolution reached the nanometer range. Interface widths of boron-doped diamond multilayers were resolved well below 1 nm/decade over a large doping range, from 3 × 10{sup 16} cm{sup −3} to 1.2 × 10{sup 21} cm{sup −3}, and confirmed a conformal growth layer by layer. - Highlights: • A double boron-delta-doped diamond sample was grown by homoepitaxy. • Delta layers are too thin and require to deconvolve the chemical depth profile. • The depth resolution function is extracted from a {sup 13}C-delta-doped diamond sample. • We confirm the conformal diamond growth layer by layer during the delta-doping.

  18. Improved depth resolution of secondary ion mass spectrometry profiles in diamond: A quantitative analysis of the delta-doping

    International Nuclear Information System (INIS)

    In this work, we used the depth resolution function (DRF) of the secondary ion mass spectrometry (SIMS) to deconvolve the boron depth profile of nanometer-thin embedded diamond layers. Thanks to an isotopic change within a thin layer, where carbon-12 (12C) and carbon-13 (13C) are substituted, the DRF was evaluated by a self-consistent algorithm. In a second step, this DRF was used to deconvolve the boron depth profile of a double delta-doped diamond analyzed under the same ion beam condition. The expected position, thickness, and boron concentration of the embedded layers were confirmed. This technique has enhanced the SIMS performance, and the depth resolution reached the nanometer range. Interface widths of boron-doped diamond multilayers were resolved well below 1 nm/decade over a large doping range, from 3 × 1016 cm−3 to 1.2 × 1021 cm−3, and confirmed a conformal growth layer by layer. - Highlights: • A double boron-delta-doped diamond sample was grown by homoepitaxy. • Delta layers are too thin and require to deconvolve the chemical depth profile. • The depth resolution function is extracted from a 13C-delta-doped diamond sample. • We confirm the conformal diamond growth layer by layer during the delta-doping

  19. Thermal Diffusion Doping of Single Crystal Diamond

    OpenAIRE

    Seo, Jung-Hun; Mikael, Solomon; Mi, Hongyi; Venkataramanan, Giri; Blanchard, James P.; Zhou, Weidong; Gong, Shaoqin; Ma, Zhenqiang

    2014-01-01

    With the best overall electronic and thermal properties, single-crystal diamond (SCD) is the extreme wide bandgap material that is expected to revolutionize power electronics and radio-frequency electronics in the future. However, turning SCD into useful semiconductors faces doping challenges, as conventional substitutional doping techniques, such as thermal diffusion and ion-implantation, are not easily applicable to SCD. Here we report a simple and easily accessible doping strategy demonstr...

  20. Electrochemical oxidation of acid black 210 dye on the boron-doped diamond electrode in the presence of phosphate ions: Effect of current density, pH, and chloride ions

    International Nuclear Information System (INIS)

    The electrochemical oxidation of acid black 210 dye (AB-210) on the boron-doped diamond (BDD) was investigated under different pH conditions. The best performance for the AB-210 oxidation occurred in alkaline phosphate solution. This is probably due to oxidizing agents such as phosphate radicals and peroxodiphosphate ions, which can be electrochemically produced with good yields on the BDD anode, mainly in alkaline solution. Under this condition, the COD (chemical oxygen demand) removal was higher than that obtained from the model proposed by Comninellis. Electrolyses performed in phosphate buffer and in the presence of chloride ions resulted in faster COD and color removals in acid and neutral solutions, but in alkaline phosphate solution, a better performance in terms of TOC removal was obtained in the absence of chloride. Moreover, organochloride compounds were detected in all electrolyses performed in the presence of chloride. The AB-210 electrooxidation on BDD using phosphate as supporting electrolyte proved to be interesting since oxidizing species generated from phosphate ions were able to completely degrade the dye without producing organochloride compounds.

  1. Phenol removal from wastewaters by electrochemical oxidation using boron doped diamond (BDD) and Ti/Ti{sub 0.7}Ru{sub 0.3}O{sub 2} DSA Registered-Sign electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Britto-Costa, P.H.; Ruotolo, L.A.M., E-mail: pluis@ufscar.br [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Engenharia Quimica

    2012-10-15

    Industrial wastewater containing non-biodegradable organic pollutants consists of highly toxic effluents whose treatment is necessary due to environmental and economical restrictions. In order to treat these effluents, an electrochemical process using a dimensionally stable anode (DSA Registered-Sign ) and boron-doped diamond (BDD) electrode was studied. The performance of these electrodes for COD removal from aqueous phenol solution was evaluated in the absence and presence of different chloride concentrations. The results showed that DSA Registered-Sign could be successfully used to remove COD when high chloride concentration (3035 mg L{sup -1}Cl{sup -}) and mild current density are employed (50 mA cm{sup -2}). On the other hand, the presence of chloride did not have the same significant effect on the COD depletion rate using BDD; however, under mild conditions (50 mA cm{sup -2}, 0.190 m s{sup -1}), the addition of 607 mg L{sup -1} Cl{sup -} improved the COD removal by approximately 52% after 8 hours of electrolysis. The effect of current density (i) and flow velocity (v) were also studied, and it was verified that they have an important role on the process performance, especially when DSA Registered-Sign is used. (author)

  2. Low-stress doped ultrananocrystalline diamond

    Energy Technology Data Exchange (ETDEWEB)

    Sumant, Anirudha V.; Buja, Federico; van Spengen, Willem Merlijn

    2016-10-25

    Nanocrystalline diamond coatings exhibit stress in nano/micro-electro mechanical systems (MEMS). Doped nanocrstalline diamond coatings exhibit increased stress. A carbide forming metal coating reduces the in-plane stress. In addition, without any metal coating, simply growing UNCD or NCD with thickness in the range of 3-4 micron also reduces in-plane stress significantly. Such coatings can be used in MEMS applications.

  3. Normal and superconducting state properties of B-doped diamond from first-principles

    Directory of Open Access Journals (Sweden)

    Lilia Boeri, Jens Kortus and Ole Krogh Andersen

    2006-01-01

    Full Text Available In this paper we give a theoretical description of the superconducting and normal-state properties of hole-doped diamond based on ab initio calculations. Our aim is to provide a useful reference to compare the theoretical predictions with the experimental data. We also discuss the advantages and drawbacks of the virtual crystal approximation (VCA, which we adopted to model the boron doping, comparing our results with supercell calculations.

  4. XPS analysis of boron doped heterofullerenes

    Energy Technology Data Exchange (ETDEWEB)

    Schnyder, B.; Koetz, R. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Muhr, H.J.; Nesper, R. [ETH Zurich, Zurich (Switzerland)

    1997-06-01

    Boron heterofullerenes were generated through arc-evaporation of doped graphite rods in a helium atmosphere. According to mass spectrometric analysis only mono-substituted fullerenes like C{sub 59}B, C{sub 69}B and higher homologues together with a large fraction of higher undoped fullerenes were extracted and enriched when pyridine was used as the solvent. XPS analysis of the extracts indicated the presence of two boron species with significantly different binding energies. One peak was assigned to borid acid. The second one corresponds to boron in the fullerene cage, which is mainly C{sub 59}B, according to the mass spectrum. This boron is in a somewhat higher oxidation state than that of ordinary boron-carbon compounds. The reported synthesis and extraction procedure opens a viable route for production of macroscopic amounts of these compounds. (author) 2 figs., 1 tab., 7 refs.

  5. Innovative boron nitride-doped propellants

    Directory of Open Access Journals (Sweden)

    Thelma Manning

    2016-04-01

    Full Text Available The U.S. military has a need for more powerful propellants with balanced/stoichiometric amounts of fuel and oxidants. However, balanced and more powerful propellants lead to accelerated gun barrel erosion and markedly shortened useful barrel life. Boron nitride (BN is an interesting potential additive for propellants that could reduce gun wear effects in advanced propellants (US patent pending 2015-026P. Hexagonal boron nitride is a good lubricant that can provide wear resistance and lower flame temperatures for gun barrels. Further, boron can dope steel, which drastically improves its strength and wear resistance, and can block the formation of softer carbides. A scalable synthesis method for producing boron nitride nano-particles that can be readily dispersed into propellants has been developed. Even dispersion of the nano-particles in a double-base propellant has been demonstrated using a solvent-based processing approach. Stability of a composite propellant with the BN additive was verified. In this paper, results from propellant testing of boron nitride nano-composite propellants are presented, including closed bomb and wear and erosion testing. Detailed characterization of the erosion tester substrates before and after firing was obtained by electron microscopy, inductively coupled plasma and x-ray photoelectron spectroscopy. This promising boron nitride additive shows the ability to improve gun wear and erosion resistance without any destabilizing effects to the propellant. Potential applications could include less erosive propellants in propellant ammunition for large, medium and small diameter fire arms.

  6. Innovative boron nitride-doped propellants

    Institute of Scientific and Technical Information of China (English)

    Thelma MANNING; Henry GRAU; Paul MATTER; Michael BEACHY; Christopher HOLT; Samuel SOPOK; Richard FIELD; Kenneth KLINGAMAN; Michael FAIR; John BOLOGNINI; Robin CROWNOVER; Carlton P. ADAM; Viral PANCHAL; Eugene ROZUMOV

    2016-01-01

    The U.S. military has a need for more powerful propellants with balanced/stoichiometric amounts of fuel and oxidants. However, balanced and more powerful propellants lead to accelerated gun barrel erosion and markedly shortened useful barrel life. Boron nitride (BN) is an interesting potential additive for propellants that could reduce gun wear effects in advanced propellants (US patent pending 2015-026P). Hexagonal boron nitride is a good lubricant that can provide wear resistance and lower flame temperatures for gun barrels. Further, boron can dope steel, which drastically improves its strength and wear resistance, and can block the formation of softer carbides. A scalable synthesis method for producing boron nitride nano-particles that can be readily dispersed into propellants has been developed. Even dispersion of the nano-particles in a double-base propellant has been demonstrated using a solvent-based processing approach. Stability of a composite propellant with the BN additive was verified. In this paper, results from propellant testing of boron nitride nano-composite propellants are presented, including closed bomb and wear and erosion testing. Detailed characterization of the erosion tester substrates before and after firing was obtained by electron microscopy, inductively coupled plasma and x-ray photoelectron spectroscopy. This promising boron nitride additive shows the ability to improve gun wear and erosion resistance without any destabilizing effects to the propellant. Potential applications could include less erosive propellants in propellant ammunition for large, medium and small diameter fire arms.

  7. Electro-Fenton, UVA photoelectro-Fenton and solar photoelectro-Fenton degradation of the drug ibuprofen in acid aqueous medium using platinum and boron-doped diamond anodes

    Energy Technology Data Exchange (ETDEWEB)

    Skoumal, Marcel; Rodriguez, Rosa Maria; Cabot, Pere Lluis; Centellas, Francesc; Garrido, Jose Antonio; Arias, Conchita [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Brillas, Enric [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain)], E-mail: brillas@ub.edu

    2009-02-28

    The degradation of a 41 mg dm{sup -3} ibuprofen (2-(4-isobutylphenyl)propionic acid) solution of pH 3.0 has been comparatively studied by electrochemical advanced oxidation processes (EAOPs) like electro-Fenton, UVA photoelectro-Fenton and solar photoelectro-Fenton at constant current density. Experiments were performed in a one-compartment cell with a Pt or boron-doped diamond (BDD) anode and an O{sub 2}-diffusion cathode. Heterogeneous hydroxyl radical ({center_dot}OH) is generated at the anode surface from water oxidation, while homogeneous {center_dot}OH is formed from Fenton's reaction between Fe{sup 2+} and H{sub 2}O{sub 2} generated at the cathode, being its production strongly enhanced from photo-Fenton reaction induced by sunlight. Higher mineralization is attained in all methods using BDD instead Pt, because the former produces greater quantity of {center_dot}OH enhancing the oxidation of pollutants. The mineralization rate increases under UVA and solar irradiation by the rapid photodecomposition of complexes of Fe(III) with acidic intermediates. The most potent method is solar photoelectro-Fenton with BDD giving 92% mineralization due to the formation of a small proportion of highly persistent final by-products. The effect of Fe{sup 2+} content, pH and current density on photoelectro-Fenton degradation has been studied. The ibuprofen decay always follows a pseudo-first-order kinetics and its destruction rate is limited by current density and UV intensity. Aromatics such as 1-(1-hydroxyethyl)-4-isobutylbenzene, 4-isobutylacetophenone, 4-isobutylphenol and 4-ethylbenzaldehyde, and carboxylic acids such as pyruvic, acetic, formic and oxalic have been identified as oxidation by-products. Oxalic acid is the ultimate by-product and the fast photodecarboxylation of its complexes with Fe(III) under UVA or solar irradiation explains the higher oxidation power of photoelectro-Fenton methods in comparison to electro-Fenton procedures.

  8. 因子设计法优化掺硼金刚石电催化降解染料废水%Electrocatalytic degradation of dye wastewater on boron-doped diamond using factorial design methodology

    Institute of Scientific and Technical Information of China (English)

    杨丽姣; 周慧芬; 张春永

    2012-01-01

    掺硼金刚石电催化工艺(BDD工艺)作为当前热门的水处理技术,已被成功用于降解多种有机污染物。采用因子设计方法,考查了BDD工艺对偶氮染料金橙-Ⅱ的降解效能。实验选用染料初始浓度、反应时间、电解质浓度、施加电流和流速作为操作参数,并以脱色率作为响应指标来评估各参数的统计学显著性。在考察的5个因素中,前两者对于处理效果具有最为显著的影响。为此,在高因子水平情况下又进一步分析了它们的主效应和相互效应,同时构造了回归模型。实验结果表明,因子设计法对于优化BDD工艺是非常适用的,并显示了其实际应用的前景。%As an attractive technique of water treatment,the electrocatalytic technology concerning boron-doped diamond(BDD) technology has been successfully applied to the degradation of various organic pollutants.The removal efficiency of an azonic dye(Orange-Ⅱ) was investigated using BDD technology.A factorial design methodology was implemented to evaluate the statistically important operating parameters,among initial dye concentration,treatment time,electrolyte concentration,applied current and flow rate,on treatment efficiency;the latter was assessed in terms of color removal rate.Of the five parameters tested,the first two had a considerable effect on the treatment performance.Hence,analysis was repeated under more intense conditions to study their main and interaction effects,as well as to construct a regression model.As a result,the factorial design methodology was proved to be very suitable in optimizing the BDD technology,thus showing great promise for real applications.

  9. Mineralization of phthalic acid by solar photoelectro-Fenton with a stirred boron-doped diamond/air-diffusion tank reactor: Influence of Fe3+ and Cu2+ catalysts and identification of oxidation products

    International Nuclear Information System (INIS)

    Highlights: • Almost total mineralization of phthalic acid by solar photoelectro-Fenton with Fe3+, Cu2+ and Fe3+–Cu2+ mixtures. • Hydroxyl radical generation from photo-Fenton reaction under solar radiation. • Enhancement of the mineralization rate using Fe3+ and small amounts of Cu2+. • Detection of eleven aromatic intermediates and six short-linear carboxylic acids. • Oxidation of Cu(II)-carboxylate complexes with ·OH and photolysis of Fe(III)-carboxylate species. -- Abstract: Here, the substrate decay and mineralization rate for 100 cm3 of a 2.0 mM phthalic acid solution in 0.10 M Na2SO4 of pH 3.0 have been studied by electro-Fenton (EF) and solar photoelectro-Fenton (SPEF). The electrochemical cell was a stirred tank reactor containing a 3 cm2 boron-doped diamond (BDD) anode and a 3 cm2 air-diffusion cathode that generates H2O2. Cu2+ and/or Fe3+ were added as catalysts with total concentration of 0.50 mM and a constant current density of 33.3 mA cm−2 was applied. In EF with Cu2+ or Fe3+ alone and SPEF with only Cu2+, phthalic acid decayed slowly and poor mineralization was reached because the main oxidant was ·OH produced at the BDD surface from water oxidation. In contrast, the substrate destruction was largely enhanced using SPEF with 0.50 mM Fe3+ since a high quantity of oxidant ·OH was produced in the bulk induced by photo-Fenton reaction. This treatment led to an almost total mineralization by the photolysis of generated Fe(III)-carboxylate complexes. In all cases, the decay of phthalic acid obeyed a pseudo-first-order reaction. The combination of Cu2+ and Fe3+ as catalysts accelerated the mineralization process in SPEF because Cu(II)-carboxylate complexes were also removed with ·OH formed from photo-Fenton reaction. The best SPEF process was found for 0.125 mM Cu2+ + 0.375 mM Fe3+, giving rise to 99% mineralization with 40% current efficiency and 0.294 kWh g−1 TOC energy consumption. Eleven aromatics and six short-linear carboxylic

  10. 用于航天器冷凝水处理的硼掺杂金刚石电极的制备及应用%Fabrication and Application of Boron Doped Diamond Electrodes in Condensate Water Purification in Spacecraft

    Institute of Scientific and Technical Information of China (English)

    李浩; 杨彬; 李中坚; 王传增; 韩松; 雷乐成

    2013-01-01

    Objective To effectively apply boron doped diamond (BDD) electrodes through electrochemical catalytic oxidation technology in the treatment of condensate water in spacecraft.Methods The authors manufactured a large area,equally distributed BDD electrode deposited on the Nb substrate by hot filament chemical vapor deposition (HFCVD).Then it was used to process simulated condensate water.Results Simulated condensate water 200 mL was processed with the current density of 10,13,15 mA/cm2.When the percentage of TOC removal was 80%,the required time were 150,120,100 min,and power consumption were 7.48,11.4,14.59 W,respectively.After treatment,all the alcohol type of materials in condensate water were oxidzed and no obvious delamination of the film was observed.Conclusion Compared with the PbO2 electrode and the Nb/BDD electrode,the BDD electrode has remarkable advantages in stability and treatment efficiency.%目的 通过电化学催化氧化技术,将硼掺杂金刚石(BDD)电极高效应用于航天器冷凝水的处理工作中.方法 采用热丝化学气相沉积(HFCVD)技术在铌板上制备得到了大面积、均匀分布的BDD电极,并将制得的BDD电极用于降解模拟冷凝水实验.结果 模拟冷凝水处理量为200 mL,在电流密度为10,13,15 mA/cm2条件下,达到80% TOC去除率分别需要150,120,100 min,功耗为7.48,11.4,14.59W;对处理后的冷凝水成分分析发现,冷凝水中原有的醇类物质被完全氧化;而且电极在连续运行之后也并未发现明显的剥落现象.结论 制得的BDD电极与二氧化铅电极相比,无论是在稳定性还是处理效率方面,都具有显著的优势.

  11. Enhancement of oxidation resistance via a self-healing boron carbide coating on diamond particles

    Science.gov (United States)

    Sun, Youhong; Meng, Qingnan; Qian, Ming; Liu, Baochang; Gao, Ke; Ma, Yinlong; Wen, Mao; Zheng, Weitao

    2016-02-01

    A boron carbide coating was applied to diamond particles by heating the particles in a powder mixture consisting of H3BO3, B and Mg. The composition, bond state and coverage fraction of the boron carbide coating on the diamond particles were investigated. The boron carbide coating prefers to grow on the diamond (100) surface than on the diamond (111) surface. A stoichiometric B4C coating completely covered the diamond particle after maintaining the raw mixture at 1200 °C for 2 h. The contribution of the boron carbide coating to the oxidation resistance enhancement of the diamond particles was investigated. During annealing of the coated diamond in air, the priory formed B2O3, which exhibits a self-healing property, as an oxygen barrier layer, which protected the diamond from oxidation. The formation temperature of B2O3 is dependent on the amorphous boron carbide content. The coating on the diamond provided effective protection of the diamond against oxidation by heating in air at 1000 °C for 1 h. Furthermore, the presence of the boron carbide coating also contributed to the maintenance of the static compressive strength during the annealing of diamond in air.

  12. Enhancement of oxidation resistance via a self-healing boron carbide coating on diamond particles.

    Science.gov (United States)

    Sun, Youhong; Meng, Qingnan; Qian, Ming; Liu, Baochang; Gao, Ke; Ma, Yinlong; Wen, Mao; Zheng, Weitao

    2016-02-02

    A boron carbide coating was applied to diamond particles by heating the particles in a powder mixture consisting of H3BO3, B and Mg. The composition, bond state and coverage fraction of the boron carbide coating on the diamond particles were investigated. The boron carbide coating prefers to grow on the diamond (100) surface than on the diamond (111) surface. A stoichiometric B4C coating completely covered the diamond particle after maintaining the raw mixture at 1200 °C for 2 h. The contribution of the boron carbide coating to the oxidation resistance enhancement of the diamond particles was investigated. During annealing of the coated diamond in air, the priory formed B2O3, which exhibits a self-healing property, as an oxygen barrier layer, which protected the diamond from oxidation. The formation temperature of B2O3 is dependent on the amorphous boron carbide content. The coating on the diamond provided effective protection of the diamond against oxidation by heating in air at 1000 °C for 1 h. Furthermore, the presence of the boron carbide coating also contributed to the maintenance of the static compressive strength during the annealing of diamond in air.

  13. Doping and cluster formation in diamond

    KAUST Repository

    Schwingenschlögl, Udo

    2011-09-09

    Introducing a cluster formation model, we provide a rational fundamental viewpoint for the difficulty to achieve n-type dopeddiamond. We argue that codoping is the way forward to form appropriately doped shallow regions in diamond and other forms of carbon such as graphene. The electronegativities of the codopants are an important design criterion for the donor atom to efficiently donate its electron. We propose that the nearest neighbour codopants should be of a considerably higher electronegativity compared to the donor atom. Codoping strategies should focus on phosphorous for which there are a number of appropriate codopants.

  14. Doping Silicon Wafers with Boron by Use of Silicon Paste

    Institute of Scientific and Technical Information of China (English)

    Yu Gao; Shu Zhou; Yunfan Zhang; Chen Dong; Xiaodong Pi; Deren Yang

    2013-01-01

    In this work we introduce recently developed silicon-paste-enabled p-type doping for silicon.Boron-doped silicon nanoparticles are synthesized by a plasma approach.They are then dispersed in solvents to form silicon paste.Silicon paste is screen-printed at the surface of silicon wafers.By annealing,boron atoms in silicon paste diffuse into silicon wafers.Chemical analysis is employed to obtain the concentrations of boron in silicon nanoparticles.The successful doping of silicon wafers with boron is evidenced by secondary ion mass spectroscopy (SIMS) and sheet resistance measurements.

  15. Three-dimensional MgB2-type superconductivity in hole-doped diamond.

    Science.gov (United States)

    Boeri, Lilia; Kortus, Jens; Andersen, O K

    2004-12-01

    We substantiate by numerical and analytical calculations that the recently discovered superconductivity below 4 K in 3% boron-doped diamond is caused by electron-phonon coupling of the same type as in MgB2, albeit in three dimensions. Holes at the top of the zone-centered, degenerate sigma-bonding valence-band couple strongly to the optical bond-stretching modes. The increase from two to three dimensions reduces the mode softening crucial for T(c) reaching 40 K in MgB2. Even if diamond had the same bare coupling constant as MgB2, which could be achieved with 10% doping, T(c) would be only 25 K. Superconductivity above 1 K in Si (Ge) requires hole doping beyond 5% (10%).

  16. Synthesis and characterization of boron-doped carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Ceragioli, H J; Peterlevitz, A C; Quispe, J C R; Pasquetto, M P; Sampaio, M A; Baranauskas, V [Faculdade de Engenharia Eletrica e Computacao, Departamento de Semicondutores, Instrumentos e Fotonica, Universidade Estadual de Campinas, UNICAMP, Av. Albert Einstein N.400, 13083-852 Campinas SP Brasil (Brazil); Larena, A [Department of Chemical Industrial Engineering and Environment, Universidad Politecnica de Madrid, E.T.S. Ingenieros Industriales, C/ Jose Gutierrez Abascal, Madrid (Spain)], E-mail: vitor.baranauskas@gmail.com

    2008-03-15

    Boron-doped carbon nanotubes have been prepared by chemical vapour deposition of ethyl alcohol doped with B{sub 2}O{sub 3} using a hot-filament system. Multi-wall carbon nanotubes of diameters in the range of 30-100 nm have been observed by field emission scanning electron microscopy (FESEM). Raman measurements indicated that the degree of C-C sp{sup 2} order decreased with boron doping. Lowest threshold fields achieved were 1.0 V/{mu}m and 2.1 V/{mu}m for undoped and boron-doped samples, respectively.

  17. Precursor design of vapour deposited cubic boron nitride versus diamond

    International Nuclear Information System (INIS)

    The similarities and dissimilarities in the growth of diamond vs. cubic boron nitride (c-BN) were studied using quantum mechanical calculations. Great similarities were observed when considering the surface stabilization by H atoms. Very great similarities were recorded when considering the adsorption of various growth species to these materials. It was found necessary to avoid mixtures of B- and N-containing species in the gas phase during c-BN growth, since they should most probably result in a mixture of these species also on the surfaces. Greater dissimilarities were observed when studying the surface migrations on the diamond and c-BN surfaces and nucleation of the cubic phases on the corresponding hexagonal ones. Nucleation of diamond/c-BN on graphite/h-BN was found to be energetically feasible. This was calculated to be especially the situation for the armchair edge of the basal plane of h-BN and of the zigzag edge of the basal plane of graphite. These theoretical results can be used as guidelines in the strive towards thin film deposition of c-BN using gentle chemical vapour deposition methods like atomic layer deposition. (author)

  18. Ion implantation of diamond: Damage, doping, and lift-off

    Energy Technology Data Exchange (ETDEWEB)

    Parikh, N.R.; McGucken, E.; Swanson, M.L. [North Carolina Univ., Chapel Hill, NC (United States). Dept. of Physics and Astronomy; Hunn, J.D.; White, C.W.; Zuhr, R.A. [Oak Ridge National Lab., TN (United States)

    1993-09-01

    In order to make good quality economical diamond electronic devices, it is essential to grow films and to dope these films to obtain n- and p- type conductivity. This review talk discuss first doping by ion implantation plus annealing of the implantation damage, and second flow to make large area single crystal diamonds. C implantation damage below an estimated Frenkel defect concentration of 7% could be recovered almost completely by annealing at 950C. For a defect concentration between 7 and 10%, a stable damage form of diamond (``green diamond``) was formed by annealing. At still higher damage levels, the diamond graphitized. To introduce p-type doping, we have co-implanted B and C into natural diamond at 77K, followed by annealing up to 1100C. The resulting semiconducting material has electrical properties similar to those of natural B-doped diamond. To create n-type diamond, we have implanted Na{sup +}, P+ and As{sup +} ions and have observed semiconducting behavior. This has been compared with carbon or noble element implantation, in an attempt to isolate the effect of radiation damage. Recently, in order to obtain large area signal crystals, we have developed a novel technique for removing thin layers of diamond from bulk or homoepitaxial films. This method consists of ion implantation, followed by selective etching. High energy (4--5 MeV) implantation of carbon or oxygen ions creates a well-defined layer of damaged diamond buried at a controlled depth. This layer is graphitized and selectivity etched either by heating at 550C in an oxygen ambient or by electrolysis. This process successfully lifts off the diamond plate above the graphite layer. The lift-off method, combined with well-established homoepitaxial growth processes, has potential for fabrication of large area single-crystal diamond sheets.

  19. Investigation of low-resistivity from hydrogenated lightly B-doped diamond by ion implantation

    Directory of Open Access Journals (Sweden)

    Cui Xia Yan et al

    2008-01-01

    Full Text Available We have implanted boron (B ions (dosage: 5×1014 cm-2 into diamond and then hydrogenated the sample by implantating hydrogen ions at room temperature. A p-type diamond material with a low resistivity of 7.37 mΩ cm has been obtained in our experiment, which suggests that the hydrogenation of B-doped diamond results in a low-resistivity p-type material. Interestingly, inverse annealing, in which carrier concentration decreased with increasing annealing temperature, was observed at annealing temperatures above 600 °C. In addition, the formation mechanism of a low-resistivity material has been studied by density functional theory calculation using a plane wave method.

  20. Enhanced optoelectronic performances of vertically aligned hexagonal boron nitride nanowalls-nanocrystalline diamond heterostructures

    Science.gov (United States)

    Sankaran, Kamatchi Jothiramalingam; Hoang, Duc Quang; Kunuku, Srinivasu; Korneychuk, Svetlana; Turner, Stuart; Pobedinskas, Paulius; Drijkoningen, Sien; van Bael, Marlies K.; D' Haen, Jan; Verbeeck, Johan; Leou, Keh-Chyang; Lin, I.-Nan; Haenen, Ken

    2016-07-01

    Field electron emission (FEE) properties of vertically aligned hexagonal boron nitride nanowalls (hBNNWs) grown on Si have been markedly enhanced through the use of nitrogen doped nanocrystalline diamond (nNCD) films as an interlayer. The FEE properties of hBNNWs-nNCD heterostructures show a low turn-on field of 15.2 V/μm, a high FEE current density of 1.48 mA/cm2 and life-time up to a period of 248 min. These values are far superior to those for hBNNWs grown on Si substrates without the nNCD interlayer, which have a turn-on field of 46.6 V/μm with 0.21 mA/cm2 FEE current density and life-time of 27 min. Cross-sectional TEM investigation reveals that the utilization of the diamond interlayer circumvented the formation of amorphous boron nitride prior to the growth of hexagonal boron nitride. Moreover, incorporation of carbon in hBNNWs improves the conductivity of hBNNWs. Such a unique combination of materials results in efficient electron transport crossing nNCD-to-hBNNWs interface and inside the hBNNWs that results in enhanced field emission of electrons. The prospective application of these materials is manifested by plasma illumination measurements with lower threshold voltage (370 V) and longer life-time, authorizing the role of hBNNWs-nNCD heterostructures in the enhancement of electron emission.

  1. Enhanced optoelectronic performances of vertically aligned hexagonal boron nitride nanowalls-nanocrystalline diamond heterostructures.

    Science.gov (United States)

    Sankaran, Kamatchi Jothiramalingam; Hoang, Duc Quang; Kunuku, Srinivasu; Korneychuk, Svetlana; Turner, Stuart; Pobedinskas, Paulius; Drijkoningen, Sien; Van Bael, Marlies K; D' Haen, Jan; Verbeeck, Johan; Leou, Keh-Chyang; Lin, I-Nan; Haenen, Ken

    2016-01-01

    Field electron emission (FEE) properties of vertically aligned hexagonal boron nitride nanowalls (hBNNWs) grown on Si have been markedly enhanced through the use of nitrogen doped nanocrystalline diamond (nNCD) films as an interlayer. The FEE properties of hBNNWs-nNCD heterostructures show a low turn-on field of 15.2 V/μm, a high FEE current density of 1.48 mA/cm(2) and life-time up to a period of 248 min. These values are far superior to those for hBNNWs grown on Si substrates without the nNCD interlayer, which have a turn-on field of 46.6 V/μm with 0.21 mA/cm(2) FEE current density and life-time of 27 min. Cross-sectional TEM investigation reveals that the utilization of the diamond interlayer circumvented the formation of amorphous boron nitride prior to the growth of hexagonal boron nitride. Moreover, incorporation of carbon in hBNNWs improves the conductivity of hBNNWs. Such a unique combination of materials results in efficient electron transport crossing nNCD-to-hBNNWs interface and inside the hBNNWs that results in enhanced field emission of electrons. The prospective application of these materials is manifested by plasma illumination measurements with lower threshold voltage (370 V) and longer life-time, authorizing the role of hBNNWs-nNCD heterostructures in the enhancement of electron emission. PMID:27404130

  2. Submicron cubic boron nitride as hard as diamond

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guoduan; Kou, Zili, E-mail: kouzili@scu.edu.cn, E-mail: yanxz@hpstar.ac.cn; Lei, Li; Peng, Fang; Wang, Qiming; Wang, Kaixue; Wang, Pei; Li, Liang; Li, Yong; Wang, Yonghua [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Yan, Xiaozhi, E-mail: kouzili@scu.edu.cn, E-mail: yanxz@hpstar.ac.cn; Li, Wentao [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203 (China); Bi, Yan [Institute of Fluid Physics and National Key Laboratory of Shockwave and Detonation Physic, China Academy of Engineering Physics, Mianyang 621900 (China); Leng, Yang [Department of Mechanical Engineering, Hong Kong University of Science and Technology, Kowloon, Hong Kong (China); He, Duanwei [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Institute of Fluid Physics and National Key Laboratory of Shockwave and Detonation Physic, China Academy of Engineering Physics, Mianyang 621900 (China)

    2015-03-23

    Here, we report the sintering of aggregated submicron cubic boron nitride (sm-cBN) at a pressure of 8 GPa. The sintered cBN compacts exhibit hardness values comparable to that of single crystal diamond, fracture toughness about 5-fold that of cBN single crystal, in combination with a high oxidization temperature. Thus, another way has been demonstrated to improve the mechanical properties of cBN besides reducing the grain size to nano scale. In contrast to other ultrahard compacts with similar hardness, the sm-cBN aggregates are better placed for potential industrial application, as their relative low pressure manufacturing perhaps be easier and cheaper.

  3. Physical properties of CVD boron-doped multiwalled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Mondal, Kartick C. [Molecular Sciences Institute and School of Chemistry, University of the Witwatersrand, P.O. Wits, 2050 Johannesburg (South Africa); DST/NRF Centre of Excellence in Strong Materials, P.O. Wits, 2050 Johannesburg (South Africa); Strydom, Andre M. [Department of Physics, University of Johannesburg, PO Box 524, Auckland Park 2006 (South Africa)], E-mail: amstrydom@uj.ac.za; Erasmus, Rudolph M.; Keartland, Jonathan M. [DST/NRF Centre of Excellence in Strong Materials, P.O. Wits, 2050 Johannesburg (South Africa); School of Physics, University of the Witwatersrand, P.O. Wits, 2050 Johannesburg (South Africa); Coville, Neil J. [Molecular Sciences Institute and School of Chemistry, University of the Witwatersrand, P.O. Wits, 2050 Johannesburg (South Africa); DST/NRF Centre of Excellence in Strong Materials, P.O. Wits, 2050 Johannesburg (South Africa)], E-mail: Neil.Coville@wits.ac.za

    2008-10-15

    The effects of boron doping and electron correlation on the transport properties of CVD boron-doped multiwalled carbon nanotubes are reported. The boron-doped multiwalled carbon nanotubes were characterized by TEM as well as Raman spectroscopy using different laser excitations (viz. 488, 514.5 and 647 nm). The intensity of the D-band laser excitation line increased after the boron incorporation into the carbon nanotubes. The G-band width increased on increasing the boron concentration, indicating the decrease of graphitization with increasing boron concentration. Electrical conductivity of the undoped and boron-doped carbon nanotubes reveal a 3-dimensional variable-range-hopping conductivity over a wide range of temperature, viz. from room temperature down to 2 K. The electrical conductivity is not found to be changed significantly by the present levels of B-doping. Electron Paramagnetic Resonance (EPR) results for the highest B-doped samples showed similarities with previously reported EPR literature measurements, but the low concentration sample gives a very broad ESR resonance line.

  4. Boron doping of graphene-pushing the limit.

    Science.gov (United States)

    Chaban, Vitaly V; Prezhdo, Oleg V

    2016-08-25

    Boron-doped derivatives of graphene have been intensely investigated because of their electronic and catalytic properties. The maximum experimentally observed concentration of boron atoms in graphite was 2.35% at 2350 K. By employing quantum chemistry coupled with molecular dynamics, we identified the theoretical doping limit for single-layer graphene at different temperatures, demonstrating that it is possible to achieve much higher boron doping concentrations. According to the calculations, 33.3 mol% of boron does not significantly undermine thermal stability, whereas 50 mol% of boron results in critical backbone deformations, which occur when three or more boron atoms enter the same six-member ring. Even though boron is less electro-negative than carbon, it tends to act as an electron acceptor in the vicinity of C-B bonds. The dipole moment of B-doped graphene depends strongly on the distribution of dopant atoms within the sheet. Compared with N-doped graphene, the dopant-dopant bonds are less destructive in the present system. The reported results motivate efforts to synthesize highly B-doped graphene for semiconductor and catalytic applications. The theoretical predictions can be validated through direct chemical synthesis. PMID:27533648

  5. Doping of high quality c-BN films epitaxially grown on top of diamond(001)

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Hong; Wang, Xuyang; Pongrac, Ivan; Ziemann, Paul [Institut fuer Festkoerperphysik, Universitaet Ulm (Germany); Renaux, Fabian; Hecq, Michel; Bittencourt, Carla [University of Mons-Hainaut, Mons (Belgium)

    2008-07-01

    Since it first synthesis in 1957 cubic boron nitride (c-BN) has attracted considerable interest due to its extreme physical and chemical properties. Besides as a superhard material second to diamond, it exhibits a wide band gap (6.4 eV) and high thermal conductivity making c-BN attractive as a high temperature electronic material. The recently achieved heteroepitaxial growth of c-BN films on top of diamond(001) opened a promising window for e.g. c-BN/diamond pn-junctions. We present results on the doping of high quality c-BN samples epitaxially grown on to diamond(001). XPS combined with ToF-SIMS results showed that metallic impurities within such epitaxial films are below several ppm leaving carbon and oxygen as the main impurities, which are homogeneously distributed inside the film. As a result, the nominally undoped c-BN films are p-type conducting as revealed by Hall effect. Si{sup +} was chosen to dope these epitaxial c-BN films by either in-situ adding Si{sup +} during film growth, or ex-situ doping by cold implantation and rapid thermal annealing (CIRA). In both cases, the electrical resistance of the samples is significantly decreased. Hall effect measurements indicate a related n-type conduction.

  6. Computer-aided analytical control of diamond and cubic boron nitride grits

    International Nuclear Information System (INIS)

    Methodical and information aspects of the superhard materials powder uniformity as a characteristics of the powder quality are discussed. Computer-aided analytical methods of the rapid diagnostics of the sieve granulometric composition and the external specific surface of diamond and cubic boron nitride grits are described. The results of the application of the developed methods and software to standard powders of synthetic diamond and cubic boron nitride are given

  7. Pure and doped boron nitride nanotubes

    Directory of Open Access Journals (Sweden)

    M. Terrones

    2007-05-01

    Full Text Available More than ten years ago, it was suggested theoretically that boron nitride (BN nanotubes could be produced. Soon after, various reports on their synthesis appeared and a new area of nanotube science was born. This review aims to cover the latest advances related to the synthesis of BN nanotubes. We show that these tubes can now be produced in larger amounts and, in particular, that the chemistry of BN tubes appears to be very important to the production of reinforced composites with insulating characteristics. From the theoretical standpoint, we also show that (BN-C heteronanotubes could have important implications for nanoelectronics. We believe that BN nanotubes (pure and doped could be used in the fabrication of novel devices in which pure carbon nanotubes do not perform very efficiently.

  8. Spontaneous Boron-doping of Graphene at Room Temperature

    Science.gov (United States)

    Pan, Lida; Que, Yande; Du, Shixuan; Gao, Hongjun; Pantelides, Sokrates T.

    2015-03-01

    Doping graphene with boron or nitrogen is an effective way to modify its electronic properties. However, the reaction barrier for introducing these impurities is quite high, making the doping process difficult. In this work, we propose a low-energy reaction route derived from first-principles calculations and subsequently validated by experiments. The calculations show that, when graphene is placed on a ruthenium substrate and exposed to atomic boron, boron atoms can incorporate substitutionally into the graphene sheet with an energy barrier about 0.1 eV, displacing carbon atoms below the graphene sheet where they migrates away. This result suggests that spontaneous doping by boron can take place at room temperature. Following the prediction, we grew high-quality graphene on the Ru(0001) surface and then expose it to B2H6 which decomposes into atomic boron. XPS and STM results indicate that boron dopes graphene substantially without disturbing the graphene lattice, confirming the theoretical predictions. Doping by nitrogen and co-doping by B and N will also be discussed.

  9. Preparation of p-n Junction Diode by B-Doped Diamond Film Grown on Si-Doped c-BN

    Institute of Scientific and Technical Information of China (English)

    王成新; 高春晓; 张铁臣; 刘洪武; 李迅; 韩永吴; 骆继峰; 申彩霞

    2002-01-01

    A heterojunction diode has been fabricated by boron-doped p-type diamond thin film grown epitaxially ona silicon-doped n-type cubic boron nitride bulk crystal using the conventional hot tilament chemical vapourdeposition method. The ohmic electrode of Ti (50nm)/Mo (l00nm)/Au (300nm) for the p-type diamond filmand the bulk crystal of the c-BN were deposited by the rf planar magnetron method. Then the device wasannealed at 410°C in air for i h in order to form ohmic metal alloy. The current-voltage characteristics of theheterojunction diode were measured and the result indicated that the rectification ratio reached 10a, and theturn-on voltage and the highest current were 7 V and 0.35 mA, respectively.

  10. n-Type CVD diamond: Epitaxy and doping

    Energy Technology Data Exchange (ETDEWEB)

    Pinault-Thaury, M.-A., E-mail: marie-amandine.pinault@cnrs-bellevue.fr [Groupe d' Etude de la Matiere Condensee (GEMaC), CNRS, Universite Versailles St Quentin (UVSQ), 1, place Aristide Briand, 92195 Meudon Cedex (France); Tillocher, T.; Habka, N. [Groupe d' Etude de la Matiere Condensee (GEMaC), CNRS, Universite Versailles St Quentin (UVSQ), 1, place Aristide Briand, 92195 Meudon Cedex (France); Kobor, D. [Laboratoire de Chimie et de Physique des Materiaux (LCPM), Universite de Ziguinchor, Quartier Diabir, BP 523, Ziguinchor (Senegal); Jomard, F.; Chevallier, J.; Barjon, J. [Groupe d' Etude de la Matiere Condensee (GEMaC), CNRS, Universite Versailles St Quentin (UVSQ), 1, place Aristide Briand, 92195 Meudon Cedex (France)

    2011-10-25

    Diamond is a semiconductor with superlative properties in terms of operating temperature, breakdown voltage and thermal dissipation for high power electronic applications. The p-type doping is currently controlled but it is not the case for the n-type doping. In spite of the low solubility of substitutional donors bigger than carbon, n-type material can be achieved via impurity doping during the growth of diamond with phosphorus dopant (E{sub c} = 0.6 eV). Theoretical studies also predict arsenic as a shallower dopant (E{sub c} = 0.4 eV). This paper outlines the n-type doping issues with phosphorus and explores the arsenic doping.

  11. Hydrogen adsorption on boron doped graphene: an {\\it ab initio} study

    OpenAIRE

    Miwa, R. H.; Martins, T B; Fazzio, A.

    2007-01-01

    The electronic and structural properties of (i) boron doped graphene sheets, and (ii) the chemisorption processes of hydrogen adatoms on the boron doped graphene sheets have been examined by {\\it ab initio} total energy calculations.

  12. Photoluminescence properties of boron doped InSe single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Ertap, H., E-mail: huseyinertap@kafkas.edu.tr [Kafkas University, Faculty of Arts and Sciences, Department of Physics, 36100 Kars (Turkey); Bacıoğlu, A. [Hacattepe University, Department of Physics Engineering, 06800, Beytepe, Ankara (Turkey); Karabulut, M. [Kafkas University, Faculty of Arts and Sciences, Department of Physics, 36100 Kars (Turkey)

    2015-11-15

    Undoped and boron doped InSe single crystals were grown by Bridgman–Stockbarger technique. The PL properties of undoped, 0.1% and 0.5% boron doped InSe single crystals have been investigated at different temperatures. PL measurements revealed four emission bands labeled as A, B, C and D in all the single crystals studied. These emission bands were associated with the radiative recombination of direct free excitons (n=1), impurity-band transitions, donor–acceptor recombinations and structural defect related band (impurity atoms, defects, defect complexes, impurity-vacancy complex etc.), respectively. The direct free exciton (A) bands of undoped, 0.1% and 0.5% boron doped InSe single crystals were observed at 1.337 eV, 1.335 eV and 1.330 eV in the PL spectra measured at 12 K, respectively. Energy positions and PL intensities of the emission bands varied with boron addition. The FWHM of direct free exciton band increases while the FWHM of the D emission band decreases with boron doping. Band gap energies of undoped and boron doped InSe single crystals were calculated from the PL measurements. It was found that the band gap energies of InSe single crystals decreased with increasing boron content. - Highlights: • PL spectra of InSe crystals have been studied as a function of temperature. • Four emission bands were observed in the PL spectra at low temperatures. • PL intensity and position of free exciton band vary with doping and temperature. • Temperature dependences of the bands observed in the PL spectra were analyzed.

  13. The local structure of transition metal doped semiconducting boron carbides

    Energy Technology Data Exchange (ETDEWEB)

    Liu Jing; Dowben, P A [Department of Physics and Astronomy and the Nebraska Center for Materials and Nanoscience, Behlen Laboratory of Physics, University of Nebraska-Lincoln, PO Box 880111, Lincoln, NE 68588-0111 (United States); Luo Guangfu; Mei Waining [Department of Physics, University of Nebraska at Omaha, Omaha, NE 68182-0266 (United States); Kizilkaya, Orhan [J. Bennett Johnston Sr. Center for Advanced Microstructures and Devices, Louisiana State University, 6980 Jefferson Hwy., Baton Rouge LA 70806 (United States); Shepherd, Eric D; Brand, J I [College of Engineering, and the Nebraska Center for Materials and Nanoscience, N209 Walter Scott Engineering Center, 17th and Vine Streets, University of Nebraska-Lincoln, Lincoln, NE 68588-0511 (United States)

    2010-03-03

    Transition metal doped boron carbides produced by plasma enhanced chemical vapour deposition of orthocarborane (closo-1,2-C{sub 2}B{sub 10}H{sub 12}) and 3d metal metallocenes were investigated by performing K-edge extended x-ray absorption fine structure and x-ray absorption near edge structure measurements. The 3d transition metal atom occupies one of the icosahedral boron or carbon atomic sites within the icosahedral cage. Good agreement was obtained between experiment and models for Mn, Fe and Co doping, based on the model structures of two adjoined vertex sharing carborane cages, each containing a transition metal. The local spin configurations of all the 3d transition metal doped boron carbides, Ti through Cu, are compared using cluster and/or icosahedral chain calculations, where the latter have periodic boundary conditions.

  14. Boron and nitrogen doping in graphene antidot lattices

    Science.gov (United States)

    Brun, Søren J.; Pereira, Vitor M.; Pedersen, Thomas G.

    2016-06-01

    Bottom-up fabrication of graphene antidot lattices (GALs) has previously yielded atomically precise structures with subnanometer periodicity. Focusing on this type of experimentally realized GAL, we perform density functional theory calculations on the pristine structure as well as GALs with edge carbon atoms substituted with boron or nitrogen. We show that p - and n -type doping levels emerge with activation energies that depend on the level of hydrogenation at the impurity. Furthermore, a tight-binding parametrization together with a Green's function method are used to describe more dilute doping. Finally, random configurations of impurities in moderately doped systems are considered to show that the doping properties are robust against disorder.

  15. Influence of Boron doping on micro crystalline silicon growth

    Institute of Scientific and Technical Information of China (English)

    Li Xin-Li; Wang Guo; Chen Yong-Sheng; Yang Shi-E; Gu Jin-Hua; Lu Jing-Xiao; Gao Xiao-Yong; Li Rui; Jiao Yue-Chao; Gao Hai-Bo

    2011-01-01

    Microcrystalline silicon (Ftc-Si:H) thin films with and without boron doping are deposited using the radio-frequency plasmsrenhanced chemical vapour deposition method. The surface roughness evolutions of the silicon thin films are investigated using ex situ spectroscopic ellipsometry and an atomic force microscope. It is shown that the growth exponent β and the roughness exponent a are about 0.369 and 0.95 for the undoped thin film,respectively. Whereas,for the boron-doped pc-Si:H thin film,βincreases to 0.534 and a decreases to 0.46 due to the shadowing effect.

  16. Superconductivity and low temperature electrical transport in B-doped CVD nanocrystalline diamond

    Directory of Open Access Journals (Sweden)

    Milos Nesladek, Jiri J. Mares, Dominique Tromson, Christine Mer, Philippe Bergonzo, Pavel Hubik and Jozef Kristofik

    2006-01-01

    Full Text Available In this work, we report on superconductivity (SC found in thin B-doped nanocrystalline diamond films, prepared by the PE-CVD technique. The thickness of the films varies from about 100 to 400 nm, the films are grown on low-alkaline glass at substrate temperatures of about 500–700 °C. The SIMS measurements show that films can be heavily doped with boron in concentrations in the range of 3×1021 cm−3. The Raman spectra show Fano resonances, confirming the substitutional B-incorporation. The low temperature magnetotransport measurements reveal a positive magnetoresistance. The SC transition is observed at about Tc=1.66 K. A simple theory exploiting the concept of weak localization accounting for this transition is proposed.

  17. Electronic structures of phosphorus-doped diamond films and impacts of their vacancies

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In order to better understand the bonding mechanisms of the phosphorus-doped diamond films and the influences of the phosphorus-doped concentration on the diamond lattice integrity and conductivity,we calculate the electronic structures of the phosphorus-doped diamond with different phosphorus concentrations and the density of states in the phosphorus--doped diamond films with a vacant lattice site by the first principle method.The calculation results show the phosphorus atom only affects the bonds of a few atoms in its vicinity,and the conductivity increases as the doped concentration increases.Also in the diamond lattice with a total number of 64 atoms and introducing a vacancy into the non-nearest neighbor lattice site of a phosphorus atom,we have found that both the injuries of the phosphorus-doped diamond films and the N-type electron conductivity of diamond films could be improved.

  18. Deposition of diamond and boron nitride films by plasma chemical vapour deposition

    Energy Technology Data Exchange (ETDEWEB)

    Albella, J.M. [Universidad Autonoma, CSIC, Madrid (Spain). Inst. of Mater. Sci.; Gomez-Aleixandre, C. [Universidad Autonoma, CSIC, Madrid (Spain). Inst. of Mater. Sci.; Sanchez-Garrido, O. [Universidad Autonoma, CSIC, Madrid (Spain). Inst. of Mater. Sci.; Vazquez, L. [Universidad Autonoma, CSIC, Madrid (Spain). Inst. of Mater. Sci.; Martinez-Duart, J.M. [Universidad Autonoma, CSIC, Madrid (Spain). Inst. of Mater. Sci.

    1995-01-01

    The deposition problems of diamond and cubic boron nitride (c-BN) by chemical vapour deposition techniques are reviewed, with major emphasis on the nucleation and reaction mechanisms. A discussion is made of the main deposition parameters (i.e. gas mixture, substrate conditioning, plasma discharges etc.) which favour the formation of the cubic phase. Most of the work is devoted to diamond owing to the large progress attained in this material. In fact, the use of diamond as a hard protective coating is now on a commercial scale. By contrast, the preparation of c-BN layers with good characteristics still needs of further research. ((orig.))

  19. Morphology Analysis of Nickel-boron/ diamond Electroless Deposition

    Institute of Scientific and Technical Information of China (English)

    WANG Lin; ZHU Xuanmin; ZHOU Jian; OUYANG Shixi

    2008-01-01

    The influences of mass concentration of nickel chloride hexahydrate, sodium borohydride,ethylenediamine, pH value, bath temperature on deposition rate were studied with orthogonal experiments by a series of pre-treatments on micro-diamond particle, and the optimized parameters were obtained. Both the morphology and the composition of original diamond and the diamond with Ni-B coating were analyzed by SEM and XRD respectively. The SEM image shows that the spherical Ni-B particle is coated upon diamond.XRD pattern shows that the coating compositions are Ni and Ni2B.

  20. Innovative boron nitride-doped propellants

    OpenAIRE

    Thelma Manning; Richard Field; Kenneth Klingaman; Michael Fair; John Bolognini; Robin Crownover; Carlton P. Adam; Viral Panchal; Eugene Rozumov; Henry Grau; Paul Matter; Michael Beachy; Christopher Holt; Samuel Sopok

    2016-01-01

    The U.S. military has a need for more powerful propellants with balanced/stoichiometric amounts of fuel and oxidants. However, balanced and more powerful propellants lead to accelerated gun barrel erosion and markedly shortened useful barrel life. Boron nitride (BN) is an interesting potential additive for propellants that could reduce gun wear effects in advanced propellants (US patent pending 2015-026P). Hexagonal boron nitride is a good lubricant that can provide wear resistance and lower ...

  1. First-Principles Determination of Ultrahigh Thermal Conductivity of Boron Arsenide: A Competitor for Diamond?

    Science.gov (United States)

    Lindsay, L.; Broido, D. A.; Reinecke, T. L.

    2013-07-01

    We have calculated the thermal conductivities (κ) of cubic III-V boron compounds using a predictive first principles approach. Boron arsenide is found to have a remarkable room temperature κ over 2000Wm-1K-1; this is comparable to those in diamond and graphite, which are the highest bulk values known. We trace this behavior in boron arsenide to an interplay of certain basic vibrational properties that lie outside of the conventional guidelines in searching for high κ materials, and to relatively weak phonon-isotope scattering. We also find that cubic boron nitride and boron antimonide will have high κ with isotopic purification. This work provides new insight into the nature of thermal transport at a quantitative level and predicts a new ultrahigh κ material of potential interest for passive cooling applications.

  2. Dependence of transport properties in tunnel junction on boron doping

    Energy Technology Data Exchange (ETDEWEB)

    Shi, M.J.; Zeng, X.B.; Liu, S.Y.; Peng, W.B; Xiao, H.B; Liao, X.B.; Wang, Z.G.; Kong, G.L. [Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)

    2010-04-15

    Boron-doped hydrogenated silicon films with different gaseous doping ratio (B{sub 2}H{sub 6}/SiH{sub 4}) were fabricated as recombination p layers in tunnel junctions. The measurements of I-V characteristics of the junctions and transparency spectra of p layer indicated that the best gaseous doping ratio of the recombination layer is 0.04, which is correlated to the degradation of short range order (SRO) in the inserted p thin film. The junction with such recombination layer has small resistance, near ohmic contact. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Concepts for diamond electronics

    International Nuclear Information System (INIS)

    The present status in the development of diamond as electronic semiconductor material with wide band-gap (5.45 eV) is reviewed. Since diamond cannot be doped with shallow impurities, specific doping concepts and related diode and FET structures had to be developed, restricted to p-type boron doping. The results allow to predict that diamond high voltage switching diodes, high power RF FET sources and operation at high temperature will surpass the capability of devices designed in competing wide band-gap materials like SiC and GaN

  4. Boron doping of silicon using excimer lasers

    International Nuclear Information System (INIS)

    The use of lasers in the doping of semiconductors has been investigated extensively these last years both for photovoltaic and microelectronic applications. In this work, doping of single-crystal silicon in BCl3 ambients using a pulsed UV laser has been studied as a function of laser wavelength and fluence in order to investigate the effects of photochemical decomposition of the BCl3 gas and the effects of thermal decomposition of adsorbed layers on the doping process. Different parameters involved in the process (laser energy density, number of pulses per frame, BCl3 gas pressure) were investigated. The electrical characteristics of the doped layers are discussed

  5. Hydrogen doped thin film diamond. Properties and application for electronic devices

    International Nuclear Information System (INIS)

    The face centered cubic allotrope of carbon, diamond, is a semiconducting material which possesses a valuable combination of extreme properties such as super-hardness, highest thermal conductivity, chemical hardness, radiation hardness, wide bandgap and others. Advances in chemical vapour deposition (CVD) technology have lead to diamond becoming available in previously unattainable forms for example over large areas and with controllable purity. This has generated much research interest towards developing the knowledge and processing technology that would be necessary to fully exploit these extreme properties. Electronic devices fabricated on oxidised boron doped polycrystalline CVD diamond (PCD) displayed very poor and inconsistent characteristic. As a result, many electronic applications of polycrystalline diamond films were confined to ultra-violet (UV) and other forms of device which relied on the high intrinsic resistivity on undoped diamond films. If commercially accessible PCD films are to advance in areas which involve sophisticated electronic applications or to compete with existing semiconductors, the need for a more reliable and fully ionised dopant is paramount. This thesis describes a unique dopant discovered within the growth surface of PCD films. This dopant is related to hydrogen which arises during the growth of diamond films. The aim of this study is to characterise and identify possible applications for this form of dopant. The mechanism for carrier generation remains unknown and based on the experimental results in this work, a model is proposed. The Hall measurements conducted on this conductive layer revealed a p-type nature with promising properties for electronic device application. A more detail study based on electrical and surface science methods were carried out to identify the stability and operating conditions for this dopant. The properties of metal-semiconductor contacts on these surfaces were investigated. The fundamental knowledge

  6. Effect of Structure of Ti/Boron-doped Diamond Electrode on the Electrochemical Degradation Performance for Aspirin%多孔钛基掺硼金刚石电极结构对电催化降解阿司匹林性能的影响

    Institute of Scientific and Technical Information of China (English)

    黄卫民; 林海波

    2015-01-01

    The surface morphology and crystal structure of three-dimensional 3 D-porous titanium/boron-doped diamond( porous Ti/BDD ) and planar Ti/BDD electrodes were studied by scanning electron microscopy (SEM) and X-ray diffraction(XRD). The cyclic voltammetry measurements of porous Ti/BDD and planar Ti/BDD electrodes were also performed. Porous Ti/BDD and planar Ti/BDD electrodes were used as anodes in the degradation of Aspirin, respectively. The results indicate that porous Ti/BDD has larger total, outer, and inner charges, porosity, and actual surface area due to the porous structure. Compared to planar Ti/PDD, porous Ti/BDD electrode is better on removal rate of chemical oxygen demand( COD) and Aspirin and energy consumption.%利用扫描电子显微镜( SEM)和X射线衍射仪( XRD)对多孔Ti/BDD电极及传统平板Ti/BDD( BDD =钛基掺硼金刚石)电极进行了研究,通过循环伏安法考察了电极的背景电流和电化学窗口。以阿司匹林为模型污染物,研究了BDD电极结构对阿司匹林电催化降解的影响。结果表明,多孔Ti/BDD电极的总带电量,内、外部带电量,孔隙率和比表面积均高于平板Ti/BDD电极;多孔Ti/BDD在对COD和阿司匹林的去除率和能量消耗等方面均优于平板Ti/BDD电极。

  7. Synthesis and characterization of boron incorporated diamond-like carbon thin films

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, L.L. [Department of Mechanical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9 (Canada); Yang, Q., E-mail: qiaoqin.yang@usask.ca [Department of Mechanical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9 (Canada); Tang, Y.; Yang, L.; Zhang, C. [Department of Mechanical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9 (Canada); Hu, Y.; Cui, X. [Canadian Light Source Inc., 101 Perimeter Road, Saskatoon, SK S7N 0X4 (Canada)

    2015-08-31

    Boron incorporated diamond-like carbon (B-DLC) (up to 8 wt.% boron) thin films were synthesized on silicon wafers using biased target ion beam deposition technique, where diamond-like carbon (DLC) was deposited by ion beam deposition and boron (B) was simultaneously incorporated by biased target sputtering of a boron carbide (B{sub 4}C) target under different conditions. Pure DLC films and B–C films were also synthesized by ion beam deposition and biased target sputtering of B{sub 4}C under similar conditions, respectively, as reference samples. The microstructure and mechanical properties of the synthesized films have been characterized by various technologies. It has been found that B exists in different states in B-DLC, including carbon-rich and B-rich boron carbides, boron suboxide and boron oxide, and the oxidation of B probably occurs during the film deposition. The incorporation of B into DLC leads to the increase of sp{sup 3} bonded carbon in the films, the increase of both film hardness and elastic modulus, and the decrease of both surface roughness and friction coefficient. Furthermore, the content of sp{sup 3} bonded carbon, film hardness and elastic modulus increase, and the film surface roughness and friction coefficient decrease with the increase of B-rich carbide in the B-DLC films. - Highlights: • Biased target ion beam deposition technique is promising to produce high quality DLC based thin films; • Boron exists in different states in B-DLC thin films; • The incorporation of B to DLC with different levels leads to improved film properties; • The fraction of sp{sup 3} bonded C in B-DLC thin films increase with the increase of B-rich carbide content in the films.

  8. Hydrogen adsorption on nitrogen and boron doped graphene

    International Nuclear Information System (INIS)

    Hydrogen adsorption on boron and nitrogen doped graphene is investigated in detail by means of first-principles calculations. A comprehensive study is performed of the structural, electronic, and magnetic properties of chemisorbed hydrogen atoms and atom pairs near the dopant sites. The main effect of the substitutional atoms is charge doping which is found to greatly affect the adsorption process by increasing the binding energy at the sites closest to the substitutional species. It is also found that doping does not induce magnetism despite the odd number of electrons per atom introduced by the foreign species, and that it quenches the paramagnetic response of chemisorbed H atoms on graphene. Overall, the effects are similar for B and N doping, with only minor differences in the adsorption energetics due to different sizes of the dopant atoms and the accompanying lattice distortions. (paper)

  9. Magnesium doping of boron nitride nanotubes

    Science.gov (United States)

    Legg, Robert; Jordan, Kevin

    2015-06-16

    A method to fabricate boron nitride nanotubes incorporating magnesium diboride in their structure. In a first embodiment, magnesium wire is introduced into a reaction feed bundle during a BNNT fabrication process. In a second embodiment, magnesium in powder form is mixed into a nitrogen gas flow during the BNNT fabrication process. MgB.sub.2 yarn may be used for superconducting applications and, in that capacity, has considerably less susceptibility to stress and has considerably better thermal conductivity than these conventional materials when compared to both conventional low and high temperature superconducting materials.

  10. Combined effect of nitrogen doping and nanosteps on microcrystalline diamond films for improvement of field emission

    Energy Technology Data Exchange (ETDEWEB)

    Mengui, U.A., E-mail: ursulamengui@gmail.com [INPE – Instituto Nacional de Pesquisas Espaciais Laboratório Associado de Sensores e Materiais – LAS, Av. dos Astronautas 1758, CP 515, CEP 12.245-970, São José dos Campos, SP (Brazil); Campos, R.A.; Alves, K.A.; Antunes, E.F. [INPE – Instituto Nacional de Pesquisas Espaciais Laboratório Associado de Sensores e Materiais – LAS, Av. dos Astronautas 1758, CP 515, CEP 12.245-970, São José dos Campos, SP (Brazil); Hamanaka, M.H.M.O. [Centro de Tecnologia da Informação Renato Archer, Divisão de Superfícies de Interação e Displays, Rodovia D. Pedro I (SP 65) km 143.6, CP 6162, CEP 13089-500, Campinas, SP (Brazil); Corat, E.J.; Baldan, M.R. [INPE – Instituto Nacional de Pesquisas Espaciais Laboratório Associado de Sensores e Materiais – LAS, Av. dos Astronautas 1758, CP 515, CEP 12.245-970, São José dos Campos, SP (Brazil)

    2015-04-15

    Highlights: • Hot filament chemical vapor deposition using methane, hydrogen and a solution of urea in methanol produced nitrogen-doped diamond films. • Diamonds had the grain morphology changed for long growth time (28 h), and the nitrogen doping were evaluated by Raman spectroscopy. • Field emission characterization shows a decrease up to 70% in threshold field, related to reference diamond layer. - Abstract: Nitrogen-doped microcrystalline diamond (N-MCD) films were grown on Si substrates using a hot filament reactor with methanol solution of urea as N source. Electrostatic self-assembly seeding of nanocrystalline diamond were used to obtain continuous and uniform films. Simultaneous changes in grains morphology and work function of diamond by nitrogen doping decreased the threshold field and the angular coefficient of Fowler–Nordhein plots. The field emission properties of our N-MCD films are comparable to carbon nanotube films.

  11. Precise control of photoluminescence of silicon-vacancy color centers in homoepitaxial single-crystal diamond: evaluation of efficiency of Si doping from gas phase

    Science.gov (United States)

    Ralchenko, Victor; Sedov, Vadim; Saraykin, Vladimir; Bolshakov, Andrey; Zavedeev, Evgeny; Ashkinazi, Evgeny; Khomich, Andrew

    2016-09-01

    Ability to precisely control the Si-related color center abundance in diamond is important for the use of silicon-vacancy (SiV) defects with bright photoluminescence (PL) in quantum information technologies and optical biomarkers. Here, we evaluated the efficiency of Si incorporation in (100) plane of homoepitaxial diamond layers upon in situ doping by adding silane SiH4 in the course of diamond chemical vapor deposition in microwave plasma using CH4-H2 mixtures. Both the Si concentration in the doped samples, as determined by secondary ion mass spectrometry, and PL intensity of SiV centers at 738 nm wavelength, measured at excitation wavelength of 473 nm, demonstrate a linear increase with silane content in feed gas in the range. The incorporation efficiency f, defined as the ratio of Si concentration in diamond to that in gas, f = [Si/C]dia/[Si/C]gas is found to be (1.1 ± 0.5) × 10-3 for the silane concentrations explored, [SiH4/CH4] < 0.7 %; thus, the Si atoms are accommodated in (100) diamond face easier than nitrogen and phosphorus, but more difficult than boron. This finding allows a tailoring of the Si content and photoluminescence intensity of SiV centers in in situ doped CVD diamond.

  12. Photoluminescence Characterization of Boron-doped Si Layers Grown by Molecular Beam Epitaxy

    Institute of Scientific and Technical Information of China (English)

    LI Cheng; LAI Hong-kai; CHEN Song-yan

    2005-01-01

    Photoluminescence spectra were used to characterize the boron-doped Si layers grown by molecular beam epitaxy using HBO2 as the doping source. The influence of boron doping concentration on the dislocation-related photoluminescence spectra of molecular beam epitaxy Si layers annealed at 900 ℃ was studied with different doping concentrations and growth temperature. The broad photoluminescence band(from 0.75 eV to 0.90 eV) including D1 and D2 bands was associated with high boron doping concentration in the samples, while D3 and D4 bands might be related to oxygen precipitates.

  13. High efficiency diamond solar cells

    Science.gov (United States)

    Gruen, Dieter M.

    2008-05-06

    A photovoltaic device and method of making same. A layer of p-doped microcrystalline diamond is deposited on a layer of n-doped ultrananocrystalline diamond such as by providing a substrate in a chamber, providing a first atmosphere containing about 1% by volume CH.sub.4 and about 99% by volume H.sub.2 with dopant quantities of a boron compound, subjecting the atmosphere to microwave energy to deposit a p-doped microcrystalline diamond layer on the substrate, providing a second atmosphere of about 1% by volume CH.sub.4 and about 89% by volume Ar and about 10% by volume N.sub.2, subjecting the second atmosphere to microwave energy to deposit a n-doped ultrananocrystalline diamond layer on the p-doped microcrystalline diamond layer. Electrodes and leads are added to conduct electrical energy when the layers are irradiated.

  14. Growth and characterization of boron doped graphene by Hot Filament Chemical Vapor Deposition Technique (HFCVD)

    Science.gov (United States)

    Jafari, A.; Ghoranneviss, M.; Salar Elahi, A.

    2016-03-01

    Large-area boron doped graphene was synthesized on Cu foil (as a catalyst) by Hot Filament Chemical Vapor Deposition (HFCVD) using boron oxide powder and ethanol vapor. To investigate the effect of different boron percentages, grow time and the growth mechanism of boron-doped graphene, scanning electron microscopy (SEM), Raman scattering and X-ray photoelectron spectroscopy (XPS) were applied. Also in this experiment, the I-V characteristic carried out for study of electrical property of graphene with keithley 2361 system. Nucleation of graphene domains with an average domain size of ~20 μm was observed when the growth time is 9 min that has full covered on the Cu surface. The Raman spectroscopy show that the frequency of the 2D band down-shifts with B doping, consistent with the increase of the in-plane lattice constant, and a weakening of the B-C in-plane bond strength relative to that of C-C bond. Also the shifts of the G-band frequencies can be interpreted in terms of the size of the C-C ring and the changes in the electronic structure of graphene in the presence of boron atoms. The study of electrical property shows that by increasing the grow time the conductance increases which this result in agree with SEM images and graphene grain boundary. Also by increasing the boron percentage in gas mixer the conductance decreases since doping graphene with boron creates a band-gap in graphene band structure. The XPS results of B doped graphene confirm the existence of boron in doped graphene, which indicates the boron atoms doped in the graphene lattice are mainly in the form of BC3. The results showed that boron-doped graphene can be successfully synthesized using boron oxide powder and ethanol vapor via a HFCVD method and also chemical boron doping can be change the electrical conductivity of the graphene.

  15. Plasma-induced high efficient synthesis of boron doped reduced graphene oxide for supercapacitors

    DEFF Research Database (Denmark)

    Li, Shaobo; Wang, Zhaofeng; Jiang, Hanmei;

    2016-01-01

    In this work, we presented a novel route to synthesize boron doped reduced graphene oxide (rGO) by using the dielectric barrier discharge (DBD) plasma technology under ambient conditions. The doping of boron (1.4 at%) led to a significant improvement in the capacitance of rGO and supercapacitors...

  16. CVD Delta-Doped Boron Surface Layers for Ultra-Shallow Junction Formation

    NARCIS (Netherlands)

    Sarubbi, F.; Nanver, L.K.; Scholtes, T.L.M.

    2006-01-01

    A new doping technique is presented that uses a pure boron atmospheric/low-pressure chemical vapor deposition (AP/LPCVD) in a commercially available epitaxial reactor to form less than 2-nm-thick δ-doped boron-silicide (BxSi) layers on the silicon surface. For long exposure B segregates at the surfa

  17. Reverse annealing of boron doped polycrystalline silicon

    International Nuclear Information System (INIS)

    Thermal activation was carried out using polycrystalline silicon (poly-Si) produced through sequential-lateral-solidification or excimer-laser-crystallization (ELC) after B+ ion shower doping. The activation efficiency of the ELC samples was found to be higher than that of the SLS ones. In this regard, grain boundaries seemed to play a critical role in terms of the activation of dopants in poly-Si at low temperatures. Reverse annealing, in which a continuous loss of charge carriers occurs, was found in this study at temperatures ranging between 400 oC and 650 oC. The samples treated by rapid thermal annealing showed a lower sheet resistance than those treated by furnace annealing. Rapid thermal annealing was found to exhibit a higher activation efficiency than furnace annealing. Reverse annealing is believed to play an important role in terms of activation efficiency

  18. Reverse annealing of boron doped polycrystalline silicon

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Beop-Jong; Hong, Won-Eui [Department of Materials Science and Engineering, Hongik University, Seoul, 121-791 (Korea, Republic of); Kim, Deok Hoi; Uemoto, Tstomu; Kim, Chi Woo [LTPS Team, AMLCD Business, Samsung Electronics, Yongin-City, Gyeonggi-Do, 449-711 (Korea, Republic of); Ro, Jae-Sang [Department of Materials Science and Engineering, Hongik University, Seoul, 121-791 (Korea, Republic of)], E-mail: jsang@wow.hongik.ac.kr

    2008-07-31

    Thermal activation was carried out using polycrystalline silicon (poly-Si) produced through sequential-lateral-solidification or excimer-laser-crystallization (ELC) after B{sup +} ion shower doping. The activation efficiency of the ELC samples was found to be higher than that of the SLS ones. In this regard, grain boundaries seemed to play a critical role in terms of the activation of dopants in poly-Si at low temperatures. Reverse annealing, in which a continuous loss of charge carriers occurs, was found in this study at temperatures ranging between 400 {sup o}C and 650 {sup o}C. The samples treated by rapid thermal annealing showed a lower sheet resistance than those treated by furnace annealing. Rapid thermal annealing was found to exhibit a higher activation efficiency than furnace annealing. Reverse annealing is believed to play an important role in terms of activation efficiency.

  19. Phenol degradation by anodic oxidation on boron-doped diamond electrode combining TiO2 Photocatalysis%掺硼金刚石电极结合二氧化钛光催化阳极氧化降解苯酚

    Institute of Scientific and Technical Information of China (English)

    戎非; 顾林娟; 邱烨静; 付德刚; 吴巍

    2010-01-01

    Boron-doped diamond (BDD) electrocatalysis is combined with photocatalysis using titanium dioxide (TiO2) as a catalyst to improve pollutant-oxidation efficiency. Phenol solution is chosen as model wastewater. Different methods involving BDD and/or TiO2 during the degradation processes are compared. Parameters such as the currency density and initial concentration are varied in order to determine their effects on the oxidation process. Moreover, the degradation kinetics of phenol is experimentally studied. The results reveal the superiority of series combination of BDD and TiO2, especially the treatment process of electrocatalysis and succedent photocatalysis, and the optimum working currency density for electrocatalysis is 25.48 mA/cm2. The removal rate decreases with the increase in the initial phenol concentration and the degradation reaction follows quasi-first-order kinetics equation.%采用二氧化钛光催化结合掺硼金刚石电催化来提高污染物氧化效率.以苯酚作为模型废水污染物,分别比较了采用BDD电催化和TiO2光催化以及两者结合方法的降解过程,研究了电流密度和初始浓度等条件对降解效果的影响,并进行了反应动力学讨论.实验结果表明:与单独处理相比, BDD和TiO2组合处理方法拥有较优的苯酚去除效果,尤其是先电解后光催化的方式,其最优工作电流密度为25.48 mA/cm2,并且随着苯酚初始浓度增加,去除率随之下降.动力学研究表明反应符合准一级动力学方程.

  20. Tuning the optical response in carbon doped boron nitride nanodots

    KAUST Repository

    Mokkath, Junais Habeeb

    2014-09-04

    Time dependent density functional theory and the hybrid B3LYP functional are used to investigate the structural and optical properties of pristine and carbon doped hexagonal boron nitride nanodots. In agreement with recent experiments, the embedded carbon atoms are found to favor nucleation. Our results demonstrate that carbon clusters of different shapes promote an early onset of absorption by generating in-gap states. The nanodots are interesting for opto-electronics due to their tunable optical response in a wide energy window. We identify cluster sizes and shapes with optimal conversion efficiency for solar radiation and a wide absorption range form infrared to ultraviolet. This journal is

  1. Graphitized boron-doped carbon foams: Performance as anodes in lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Elena; Camean, Ignacio; Garcia, Roberto [Instituto Nacional del Carbon (CSIC), C/Francisco Pintado Fe 26, 33011 Oviedo (Spain); Garcia, Ana B., E-mail: anabgs@incar.csic.es [Instituto Nacional del Carbon (CSIC), C/Francisco Pintado Fe 26, 33011 Oviedo (Spain)

    2011-05-30

    Highlights: > Because of the catalytic effect of boron, graphite-like foams were prepared. > The presence of substitutional boron in carbon foams improves their anodic performance. > The graphitized boron-doped foams provide reversible capacities of 310 mA h g{sup -1}. - Abstract: The electrochemical performance as potential anodes in lithium-ion batteries of several boron-doped and non-doped graphitic foams with different degree of structural order was investigated by galvanostatic cycling. The boron-doped foams were prepared by the co-pyrolysis of a coal and two boron sources (boron oxide and a borane-pyridine complex), followed by heat treatment in the 2400-2800 deg. C temperature interval. The extent of the graphitization process of the carbon foams depends on boron concentration and source. Because of the catalytic effect of boron, lightweight graphite-like foams were prepared. Boron in the foams was found to be present as carbide (B{sub 4}C), in substitutional positions in the carbon lattice (B-C), bonded to nitrogen (B-N) and forming clusters. Larger reversible lithium storage capacities with values up to {approx}310 mA h g{sup -1} were achieved by using the boron oxide-based carbon foams. Moreover, since the electrochemical anodic performance of these boron-doped foams with different degree of structural order is similar, the beneficial effect of the presence of the B-C boron phase was inferred. However, the bonding of boron with nitrogen in the pyridine borane-based has a negative effect on lithium intercalation.

  2. Boron doped simulated graphene field effect transistor model

    Science.gov (United States)

    Sharma, Preetika; Kaur, Inderpreet; Gupta, Shuchi; Singh, Sukhbir

    2016-05-01

    Graphene based electronic devices due to its unique properties has transformed electronics. A Graphene Field Effect Transistor (GNRFET) model is simulated in Virtual Nano Lab (VNL) and the calculations are based on density functional theory (DFT). Simulations were performed on this pristine GNRFET model and the transmission spectrum was observed. The graph obtained showed a uniform energy gap of +1 to -1eV and the highest transmission peak at -1.75 eV. To this pristine model of GNRFET, doping was introduced and its effect was seen on the Fermi level obtained in the transmission spectrum. Boron as a dopant was used which showed variations in both the transmission peaks and the energy gap. In this model, first the single boron was substituted in place of carbon and Fermi level showed an energy gap of 1.5 to -0.5eV with the highest transmission peak at -1.3 eV. In another variation in the model, two carbon atoms were replaced by two boron atoms and Fermi level shifted from 2 to 0.25eV. In this observation, the highest transmission peak was observed at -1(approx.). The use of nanoelectronic devices have opened many areas of applications as GFET is an excellent building block for electronic circuits, and is being used in applications such as high-performance frequency doublers and mixers, digital modulators, phase detectors, optoelectronics and spintronics.

  3. Electron emission from conduction band of heavily phosphorus doped diamond negative electron affinity surface

    Science.gov (United States)

    Yamada, Takatoshi; Masuzawa, Tomoaki; Mimura, Hidenori; Okano, Ken

    2016-02-01

    Hydrogen (H)-terminated surfaces of diamond have attracted significant attention due to their negative electron affinity (NEA), suggesting high-efficiency electron emitters. Combined with n-type doping technique using phosphorus (P) as donors, the unique NEA surface makes diamond a promising candidate for vacuum cold-cathode applications. However, high-electric fields are needed for the electron emission from the n-type doped diamond with NEA. Here we have clarified the electron emission mechanism of field emission from P-doped diamond having NEA utilizing combined ultraviolet photoelectron spectroscopy/field emission spectroscopy (UPS/FES). An UP spectrum has confirmed the NEA of H-terminated (1 1 1) surface of P-doped diamond. Despite the NEA, electron emission occurs only when electric field at the surface exceeds 4.2  ×  106 V cm-1. Further analysis by UPS/FES has revealed that the emitted energy level is shifted, indicating that the electron emission mechanism of n-type diamond having NEA surface does not follow a standard field emission theory, but is dominated by potential barrier formed within the diamond due to upward band bending. The reduction of internal barrier is the key to achieve high-efficiency electron emitters using P-doped diamond with NEA, of which application ranges from high-resolution electron spectroscopy to novel vacuum nanoelectronics devices.

  4. Study on the Microstructure and Electrical Properties of Boron and Sulfur Codoped Diamond Films Deposited Using Chemical Vapor Deposition

    OpenAIRE

    2014-01-01

    The atomic-scale microstructure and electron emission properties of boron and sulfur (denoted as B-S) codoped diamond films grown on high-temperature and high-pressure (HTHP) diamond and Si substrates were investigated using atom force microscopy (AFM), scanning tunneling microscopy (STM), secondary ion mass spectroscopy (SIMS), and current imaging tunneling spectroscopy (CITS) measurement techniques. The films grown on Si consisted of large grains with secondary nucleation, whereas those on ...

  5. Characterisation of sputter deposited niobium and boron interlayer in the copper–diamond system

    Science.gov (United States)

    Hell, J.; Chirtoc, M.; Eisenmenger-Sittner, C.; Hutter, H.; Kornfeind, N.; Kijamnajsuk, P.; Kitzmantel, M.; Neubauer, E.; Zellhofer, K.

    2012-01-01

    In most metal matrix composites (MMCs) interfaces are decisive but hard to manipulate. Especially copper–carbon composites can exhibit excellent mechanical and thermal properties only if the Cu/C interface is modified by an optimised interlayer. Due to the excellent thermal conductivity and mechanical stability of diamond this form of carbon is preferred as reinforcement in heat sink materials (copper–diamond composite) which are often subjected to severe thermal and mechanical loads. In the present case niobium and boron interlayers of various thicknesses were deposited on diamond and vitreous carbon substrates by magnetron sputter deposition. After the coverage of all samples by a copper film, a part of the samples was subjected to heat treatment for 30 min at 800 °C under high vacuum (HV) to simulate the thermal conditions during the production of the composite material by uniaxial hot pressing. De-wetting during heat treatment leads to the formation of holes or humps in the Cu coating. This effect was investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). A comparison of time-of-flight secondary ion mass spectroscopy (TOF SIMS) profiles of heat treated samples with those of as deposited ones showed the influence of interdiffusion during the heating process. Diffusion behaviour and chemical composition of the interface were also studied by cross sectional transmission electron microscopy (X-TEM) investigations using focused ion beam (FIB) cut samples. The thermal contact resistance (TCR) of the interface was calculated from results obtained from modulated infrared radiometry (IR). Thin interlayers suppressed de-wetting most effectively and consequently the TCR at the Cu–diamond interface was found to decrease. Therefore they are promising candidates for optimising the Cu–diamond interface. PMID:23471515

  6. Study on the Microstructure and Electrical Properties of Boron and Sulfur Codoped Diamond Films Deposited Using Chemical Vapor Deposition

    Directory of Open Access Journals (Sweden)

    Zhang Jing

    2014-01-01

    Full Text Available The atomic-scale microstructure and electron emission properties of boron and sulfur (denoted as B-S codoped diamond films grown on high-temperature and high-pressure (HTHP diamond and Si substrates were investigated using atom force microscopy (AFM, scanning tunneling microscopy (STM, secondary ion mass spectroscopy (SIMS, and current imaging tunneling spectroscopy (CITS measurement techniques. The films grown on Si consisted of large grains with secondary nucleation, whereas those on HTHP diamond are composed of well-developed polycrystalline facets with an average size of 10–50 nm. SIMS analyses confirmed that sulfur was successfully introduced into diamond films, and a small amount of boron facilitated sulfur incorporation into diamond. Large tunneling currents were observed at some grain boundaries, and the emission character was better at the grain boundaries than that at the center of the crystal. The films grown on HTHP diamond substrates were much more perfect with higher quality than the films deposited on Si substrates. The local I-V characteristics for films deposited on Si or HTHP diamond substrates indicate n-type conduction.

  7. Microheater made of heavily boron doped single crystal silicon beam

    International Nuclear Information System (INIS)

    Microheater made of heavily Boron doped single crystal Si beam covered with SiO2 film, 1000 x 300 x 3 μm, is fabricated on the n type Si substrate by the anisotropic etching technique. As this microheater has an air bridge structure of low resistivity semiconductor material with positive but small temperature coefficient of resistance, a broad heating area up to 800 degrees C is easily obtained and it has quick response with the thermal time constant t of about 4 ms and has small power consumption. Since this heating area is made of p type layer in the n type substrate, this area can be electrically isolated from the substrate because of the formation of p-n junction

  8. 不同基底BDD电极对模拟染料废水的降解脱色试验%Experiment of Degradation and Decolouration for Simulated Dye Wastewater Treatment with Different Kinds of Substrates Based Boron Doped Diamond (BDD) Thin-Film Electrode

    Institute of Scientific and Technical Information of China (English)

    邢剑飞; 王珺; 李侃; 王亚林; 应迪文; 贾金平

    2013-01-01

    Boron doped diamond (BDD) thin-film is deposited on 4 kinds of substrates (Si\\Ta\\SiC\\Ti) using hot-filament chemical vapor deposition method. They were characterized by scanning electrical microscopy for properties of microstructure, and cyclic voltammetry for electrochemical properties, respectively. The results show that all four BDD thin-film electrodes have wide potential windows than graphite electrode and RuO2 electrode. Ta based BDD and SiC based BDD have fine morphological features. Ta based BDD and Ti based BDD have firm adhesion properties to the substrates and have long life-time. After electrolysis for 12 h, the film on each electrode still has a good electrolysis performance. However, the films Si based BDD and SiC based BDD started to break after 4 and 6 h, respectively. Simulated Reactive Brilliant Red X-3B wastewater was further treated using Ta based BDD thin-film electrode. Different treatment parameters, for example, voltages, concentrations of electrolyte, types of electrolyte, and pH, have been optimized. The color removal efficiency of 99 % was obtained by electrolysis after 120 min with 2.S g/L NajSO4 in acid condition. Comparing with traditional Na2SO4, NaCl is a better electrolyte.%在Si、Ta、SiC、Ti四种不同的基底上通过热丝化学气相沉积法分别生长了掺硼金刚石(BDD)薄膜.试验对BDD膜层的微观形貌、电极的电化学性能进行了研究.四种基底的BDD电极均具有较宽的电位窗口;Ta-BDD和SiC-BDD晶体形貌完整;Ta-BDD和Ti-BDD具有较好的膜基附着力,具有较长的寿命.试验表明,使用12 h后,Ta-BDD与Ti-BDD仍具有良好的电解性能,微观形貌完整,而Si-BDD和SiC-BDD分别使用4h和6h后,膜层便开始脱落.试验测定了Ta-BDD电极对活性艳红X-3B模拟染料废水的降解脱色效果,考察了不同条件(槽电压、电解质浓度、电解质种类及pH)对脱色效果的影响.结果表明:在酸性介质中,当硫酸钠浓度为2.5 g

  9. Theoretical Calculation on Optimum Si-doping Content in Boron Carbide Thin Film

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The theoretical expression of the relationship between optimum doping content and crystal structure is presented as well as the preparation methods. By using this expression, the optimum doping content of silicon-doped boron carbide thin film is calculated. The quantitative calculation value is consistent with the experimental results. This theoretical expression is also appropriate to resolve the optimum doping content for other electric materials.

  10. Plasma-induced highly efficient synthesis of boron doped reduced graphene oxide for supercapacitors.

    Science.gov (United States)

    Li, Shaobo; Wang, Zhaofeng; Jiang, Hanmei; Zhang, Limei; Ren, Jingzheng; Zheng, Mingtao; Dong, Lichun; Sun, Luyi

    2016-09-21

    In this work, we presented a novel route to synthesize boron doped reduced graphene oxide (rGO) by using the dielectric barrier discharge (DBD) plasma technology under ambient conditions. The doping of boron (1.4 at%) led to a significant improvement in the capacitance of rGO and supercapacitors based on the as-synthesized B-rGO exhibited an outstanding specific capacitance.

  11. Plasma-induced highly efficient synthesis of boron doped reduced graphene oxide for supercapacitors.

    Science.gov (United States)

    Li, Shaobo; Wang, Zhaofeng; Jiang, Hanmei; Zhang, Limei; Ren, Jingzheng; Zheng, Mingtao; Dong, Lichun; Sun, Luyi

    2016-09-21

    In this work, we presented a novel route to synthesize boron doped reduced graphene oxide (rGO) by using the dielectric barrier discharge (DBD) plasma technology under ambient conditions. The doping of boron (1.4 at%) led to a significant improvement in the capacitance of rGO and supercapacitors based on the as-synthesized B-rGO exhibited an outstanding specific capacitance. PMID:27534806

  12. The influence of electrochemical pre-treatment of B-doped diamond films on the electrodeposition of Pt

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Mauro C.; Silva, Leide G. da; Sumodjo, Paulo T.A. [Sao Paulo Univ., SP (Brazil). Inst. de Quimica]. E-mail: ptasumod@iq.usp.br

    2006-08-15

    The influence of the substrate electrochemical pre-treatment in 0.5 mol L{sup -1} H{sub 2}SO{sub 4} on the Pt electrodeposition on boron-doped diamond, BDD, film electrodes was investigated. Platinum cannot be electrodeposited on a freshly prepared BDD electrode; however, potentiodynamic cycling or anodic potential steps at short times does activate the electrode. Anodic pre-treatment plays a dual role in the behavior of Pt deposition on BDD surfaces: Pt deposition is increased at short-term anodic pre-treatments, whereas at longer pre-treatment times Pt deposition was inhibited. These facts are explained in terms of wettability changes and passivation of the surface. Conversely, the oxide layer formed in these treatments increases the dispersion level of the catalyst. (author)

  13. Effects of carbon doping on the electronic properties of boron nitride nanotubes: Tight binding calculation

    Science.gov (United States)

    Chegel, Raad

    2016-10-01

    The electronic properties of pure and carbon doped zigzag and armchair Boron Nitride Nanotubes (BNNTs) have been investigated based on tight binding formalism. It was found that the band gap is reduced due to substitution of Boron or Nitrogen atoms by carbon atoms and the doping effects of B- and N-substituted BNNTs are different. The applied electric field converts the carbon doped BNNTs from semiconductor to metal. The gap energy reduction shows an identical dependence to electric field and doping for both armchair and zigzag carbon doped BNNTs. Our results indicate that the band gap of carbon doped BNNTs is a function of the Impurity concentration, electric field strength and the direction between the electric field and dopant location. The band gap for C-doped BNNTs with four carbon atoms decreases linearly but for two carbon atoms, it is constant at first then decreases linearly.

  14. Local atomic and electronic structure of boron chemical doping in monolayer graphene.

    Science.gov (United States)

    Zhao, Liuyan; Levendorf, Mark; Goncher, Scott; Schiros, Theanne; Pálová, Lucia; Zabet-Khosousi, Amir; Rim, Kwang Taeg; Gutiérrez, Christopher; Nordlund, Dennis; Jaye, Cherno; Hybertsen, Mark; Reichman, David; Flynn, George W; Park, Jiwoong; Pasupathy, Abhay N

    2013-10-01

    We use scanning tunneling microscopy and X-ray spectroscopy to characterize the atomic and electronic structure of boron-doped and nitrogen-doped graphene created by chemical vapor deposition on copper substrates. Microscopic measurements show that boron, like nitrogen, incorporates into the carbon lattice primarily in the graphitic form and contributes ~0.5 carriers into the graphene sheet per dopant. Density functional theory calculations indicate that boron dopants interact strongly with the underlying copper substrate while nitrogen dopants do not. The local bonding differences between graphitic boron and nitrogen dopants lead to large scale differences in dopant distribution. The distribution of dopants is observed to be completely random in the case of boron, while nitrogen displays strong sublattice clustering. Structurally, nitrogen-doped graphene is relatively defect-free while boron-doped graphene films show a large number of Stone-Wales defects. These defects create local electronic resonances and cause electronic scattering, but do not electronically dope the graphene film. PMID:24032458

  15. Structures of Pt clusters on graphene doped with nitrogen, boron, and silicon: a theoretical study

    Institute of Scientific and Technical Information of China (English)

    Dai Xian-Qi; Tang Ya-Nan; Dai Ya-Wei; Li Yan-Hui; Zhao Jian-Hua; Zhao Bao; Yang Zong-Xian

    2011-01-01

    The structures of Pt clusters on nitrogen-, boron-, silicon- doped graphenes are theoretically studied using densityfunctional theory. These dopants (nitrogen, boron and silicon) each do not induce a local curvature in the graphene and the doped graphenes all retain their planar form. The formation energy of the silicon-graphene system is lower than those of the nitrogen-, boron-doped graphenes, indicating that the silicon atom is easier to incorporate into the graphene.All the substitutional impurities enhance the interaction between the Pt atom and the graphene. The adsorption energy of a Pt adsorbed on the silicon-doped graphene is much higher than those on the nitrogen- and boron-doped graphenes.The doped silicon atom can provide more charges to enhance the Pt-graphene interaction and the formation of Pt clusters each with a large size. The stable structures of Pt clusters on the doped-graphenes are dimeric, triangle and tetrahedron with the increase of the Pt coverage. Of all the studied structures, the tetrahedron is the most stable cluster which has the least influence on the planar surface of doped-graphene.

  16. Photoluminescence and Raman spectroscopy characterization of boron- and nitrogen-doped 6H silicon carbide

    DEFF Research Database (Denmark)

    Ou, Yiyu; Jokubavicius, Valdas; Liu, Chuan;

    2011-01-01

    Boron - and nitrogen-doped 6H silicon carbide epilayers grown on low off-axis 6H silicon carbide substrates have been characterized by photoluminescence and Raman spectroscopy. Combined with secondary ion mass spectrometry results, preferable doping type and optimized concentration could...

  17. Optical and electrical properties of undoped and boron doped zinc oxide synthesized by chemical route

    International Nuclear Information System (INIS)

    We have synthesized and studied the boron doped ZnO nanostructure thin films. The crystallinity of undoped and boron (B) doped ZnO (BZO) has been studied from XRD results. Using the Debye-Scherrer Formula, the grain size has been evaluated, which was found to decrease with increased doping concentration. The optical and electrical properties of (1, 3, 5 wt%) B-doped ZnO (BZO) has been investigated with reference to the undoped counterpart. The UV-VIS spectroscopic analysis revealed that the transmittance for undoped ZnO is maximum and it decreases with doping up to 3% but increases for 5% BZO. The dark as well as photo current–voltage (I–V) characteristics have been investigated in details and the changes occurred in the I-V characteristics with doping concentration as well as under illumination are also quite significant

  18. Synthesis of boron-doped graphene monolayers using the sole solid feedstock by chemical vapor deposition.

    Science.gov (United States)

    Wang, Huan; Zhou, Yu; Wu, Di; Liao, Lei; Zhao, Shuli; Peng, Hailin; Liu, Zhongfan

    2013-04-22

    Substitutionally boron-doped monolayer graphene film is grown on a large scale by using a sole phenylboronic acid as the source in a low-pressure chemical vapor deposition system. The B-doped graphene film is a homogeneous monolayer with high crystalline quality, which exhibits a stable p-type doping behavior with a considerably high room-temperature carrier mobility of about 800 cm(2) V(-1) s(-1) . PMID:23463717

  19. Endo-Fullerenes and Doped Diamond Nanocrystallite Based Solid-State Qubits

    Science.gov (United States)

    Park, Seongjun; Srivastava, Deepak; Cho, K.

    2001-01-01

    This viewgraph presentation provides information on the use of endo-fullerenes and doped diamond nanocrystallites in the development of a solid state quantum computer. Arrays of qubits, which have 1/2 nuclear spin, are more easily fabricated than arrays of similar bare atoms. H-1 can be encapsulated in a C20D20 fullerene, while P-31 can be encapsulated in a diamond nanocrystallite.

  20. Impact of nitrogen doping on growth and hydrogen impurity incorporation of thick nanocrystalline diamond films

    Institute of Scientific and Technical Information of China (English)

    Gu Li-Ping; Tang Chun-Jiu; Jiang Xue-Fan; J.L.Pintob

    2011-01-01

    A much larger amount of bonded hydrogen was found in thick nanocrystalline diamond (NCD) films produced by only adding 0.24% N2 into 4% CH4/H2 plasma, as compared to the high quality transparent microcrystalline diamond (MCD) films, grown using the same growth parameters except for nitrogen. These experimental results clearly evidence that defect formation and impurity incorporation (for example, N and H) impeding diamond grain growth is the main formation mechanism of NCD upon nitrogen doping and strongly support the model proposed in the literature that nitrogen competes with CHX (x = 1,2,3) growth species for adsorption sites.

  1. Boron-doped MnO{sub 2}/carbon fiber composite electrode for supercapacitor

    Energy Technology Data Exchange (ETDEWEB)

    Chi, Hong Zhong, E-mail: hzchi@hdu.edu.cn [College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Zhu, Hongjie [College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Gao, Linhui [Center of Materials Engineering, Zhejiang Sci-Tech University, Hangzhou 310018 (China)

    2015-10-05

    Highlights: • Interstitial ion in MnO{sub 2} lattice. • Porous film composed by interlocking worm-like nanostructure. • Boron-doped birnessite-type MnO{sub 2}/carbon fiber composite electrode. • Enhanced capacitive properties through nonmetal element doping. - Abstract: The boron-doped MnO{sub 2}/carbon fiber composite electrode has been prepared via in situ redox reaction between potassium permanganate and carbon fibers in the presence of boric acid. The addition of boron as dopant results in the increase of growth-rate of MnO{sub 2} crystal and the formation of worm-like nanostructure. Based on the analysis of binding energy, element boron incorporates into the MnO{sub 2} lattice through interstitial mode. The doped electrode with porous framework is beneficial to pseudocapacitive reaction and surface charge storage, leading to higher specific capacitance and superior rate capability. After experienced 1000 cycles, the boron-doped MnO{sub 2} still retain a higher specific capacitance by about 80% of its initial value. The fall in capacitance is blamed to be the combination of the formation of soluble Mn{sup 2+} and the absence of active site on the outer surface.

  2. Electronic structure of B-doped diamond: A first-principles study

    Directory of Open Access Journals (Sweden)

    T. Oguchi

    2006-01-01

    Full Text Available Electronic structure of B-doped diamond is studied based on first-principles calculations with supercell models for substitutional and interstitial doping at 1.5–3.1 at.% B concentrations. Substitutional doping induces holes around the valence-band maximum in a rigid-band fashion. The nearest neighbor C site to B shows a large energy shift of 1s core state, which may explain reasonably experimental features in recent photoemission and X-ray absorption spectra. Doping at interstitial Td site is found to be unstable compared with that at the substitutional site

  3. Electronic properties of graphene nanoribbon doped by boron/nitrogen pair: a first-principles study

    Institute of Scientific and Technical Information of China (English)

    Xiao Jin; Yang Zhi-Xiong; Xie Wei-Tao; Xiao Li-Xin; Xu Hui; OuYang Fang-Ping

    2012-01-01

    By using the first-principles calculations,the electronic properties of graphene nanoribbon (GNR) doped by boron/nitrogen (B/N) bonded pair are investigated. It is found that B/N bonded pair tends to be doped at the edges of GNR and B/N pair doping in GNR is easier to carry out than single B doping and unbonded B/N co-doping in GNR.The electronic structure of GNR doped by B/N pair is very sensitive to doping site besides the ribbon width and chirality. Moreover,B/N pair doping can selectively adjust the energy gap of armchair GNR and can induce the semimetal-semiconductor transmission for zigzag GNR.This fact may lead to a possible method for energy band engineering of GNRs and benefit the design of graphene electronic device.

  4. Low temperature boron doping into crystalline silicon by boron-containing species generated in Cat-CVD apparatus

    International Nuclear Information System (INIS)

    We have discovered that phosphorus (P) atoms can be doped into crystalline silicon (c-Si) at temperatures below 350 °C or even at 80 °C by using species generated by catalytic cracking reaction of phosphine (PH3) molecules with heated tungsten (W) catalyzer in Cat-CVD apparatus. As further investigation, here, we study the feasibility of low temperature doping of boron (B) atoms into c-Si by using decomposed species generated similarly from diborane (B2H6) molecules. Dependency of properties of doped layers on catalyzer temperature (Tcat) and substrate temperature (Ts) is studied by both the Van der Pauw method based on the Hall-effect measurements and secondary ion mass spectroscopy (SIMS) for B doping in addition to P doping. It is found that, similarly to P doping, the surface of n-type c-Si is converted to p-type even at Ts = 80 °C for Tcat over 800 °C when c-Si is exposed to B2H6 cracked species for a few minutes, and that the heat of substrate over 300 °C is likely to help for B doping contrary to P doping

  5. Rectifying Properties of a Nitrogen/Boron-Doped Capped-Carbon-Nanotube-Based Molecular Junction

    Institute of Scientific and Technical Information of China (English)

    ZHAO Peng; LIU De-Sheng; ZHANG Ying; WANG Pei-Ji; ZHANG Zhong

    2011-01-01

    @@ Based on the non-equilibrium Green's function method and first-principles density functional theory calculations, we investigate the electronic transport properties of a nitrogen/boron-doped capped-single-walled carbonnanotube-based molecular junction.Obvious rectifying behavior is observed and it is strongly dependent on the doping site.The best rectifying performance can be carried out when the nitrogen/boron atom dopes at a carbon site in the second layer.Moreover, the rectifying performance can be further improved by adjusting the distance between the Cso nanotube caps.%Based on the non-equilibrium Green's function method and first-principles density functional theory calculations, we investigate the electronic transport properties of a nitrogen/boron-doped capped-single-walled carbon-nanotube-based molecular junction. Obvious rectifying behavior is observed and it is strongly dependent on the doping site. The best rectifying performance can be carried out when the nitrogen/boron atom dopes at a carbon site in the second layer. Moreover, the rectifying performance can be further improved by adjusting the distance between the C60 nanotube caps.

  6. Localization of metallicity and magnetic properties of graphene and of graphene nanoribbons doped with boron clusters

    Science.gov (United States)

    Özdoğan, Cem; Kunstmann, Jens; Quandt, Alexander

    2014-06-01

    As a possible way of modifying the intrinsic properties of graphene, we study the doping of graphene by embedded boron clusters with density functional theory. Cluster doping is technologically relevant as the cluster implantation technique can be readily applied to graphene. We find that B? clusters embedded into graphene and graphene nanoribbons are structurally stable and locally metallize the system. This is done both by the reduction of the Fermi energy and by the introduction of boron states near the Fermi level. A linear chain of boron clusters forms a metallic "wire" inside the graphene matrix. In a zigzag edge graphene nanoribbon, the cluster-related states tend to hybridize with the edge and bulk states. The magnetism in boron-doped graphene systems is generally very weak. The presence of boron clusters weakens the edge magnetism in zigzag edge graphene nanoribbon, rather than making the system appropriate for spintronics. Thus, the doping of graphene with the cluster implantation technique might be a viable technique to locally metallize graphene without destroying its attractive bulk properties.

  7. Superconductivity in CVD Diamond Films

    Science.gov (United States)

    Takano, Yoshihiko

    2005-03-01

    The recent news of superconductivity 2.3K in heavily boron-doped diamond synthesized by high pressure sintering was received with considerable surprise (1). Opening up new possibilities for diamond-based electrical devices, a systematic investigation of these phenomena clearly needs to be achieved. Application of diamond to actual devices requires it to be made into the form of wafers or thin films. We show unambiguous evidence for superconductivity in a heavily boron-doped diamond thin film deposited by the microwave plasma assisted chemical vapor deposition (MPCVD) method (2). An advantage of the MPCVD deposited diamond is that it can control boron concentration in its wider range, particularly in (111) oriented films. The temperature dependence of resistivity for (111) and (100) homoepitaxial thin films were measured under several magnetic fields. Superconducting transition temperatures of (111) homoepitaxial film are determined to be 11.4K for Tc onset and 7.2K for zero resistivity. And the upper critical field is estimated to be about 8T. These values are 2-3 times higher than these ever reported (1,3). On other hand, for (100) homoepitaxial film, Tc onset and Tc zero resistivity were estimated to be 6.3 and 3.2K respectively. The superconductivity in (100) film was strongly suppressed even at the same boron concentration. These differences of superconductivity in film orientation will be discussed. These findings established the superconductivity as a universal property of boron-doped diamond, demonstrating that device application is indeed a feasible challenge. 1. E. A. Ekimov et al. Nature, 428, 542 (2004). 2. Y. Takano et al., Appl. Phys. Lett. 85, 2851 (2004). 3. E. Bustarret et al., ond-mat 0408517.

  8. Femtosecond Laser Crystallization of Boron-doped Amorphous Hydrogenated Silicon Films

    Directory of Open Access Journals (Sweden)

    P.D. Rybalko

    2016-10-01

    Full Text Available Crystallization of amorphous hydrogenated silicon films with femtosecond laser pulses is one of the promising ways to produce nanocrystalline silicon for photovoltaics. The structure of laser treated films is the most important factor determining materials' electric and photoelectric properties. In this work we investigated the effect of femtosecond laser irradiation of boron doped amorphous hydrogenated silicon films with different fluences on crystalline volume fraction and electrical properties of this material. A sharp increase of conductivity and essential decrease of activation energy of conductivity temperature dependences accompany the crystallization process. The results obtained are explained by increase of boron doping efficiency in crystalline phase of modified silicon film.

  9. CVD Delta-Doped Boron Surface Layers for Ultra-Shallow Junction Formation

    OpenAIRE

    Sarubbi, F.; Nanver, L.K.; Scholtes, T.L.M.

    2006-01-01

    A new doping technique is presented that uses a pure boron atmospheric/low-pressure chemical vapor deposition (AP/LPCVD) in a commercially available epitaxial reactor to form less than 2-nm-thick δ-doped boron-silicide (BxSi) layers on the silicon surface. For long exposure B segregates at the surface to form a very slow growing amorphous layer of pure B (α-B). The electrical properties of the as-deposited α- B/BxSi stack have been studied by fabricating and measuring diodes where the B depos...

  10. Detecting CO, NO and NO2 gases by Boron-doped graphene nanoribbon molecular devices

    Science.gov (United States)

    Xie, Zhen; Zuo, Xi; Zhang, Guang-Ping; Li, Zong-Liang; Wang, Chuan-Kui

    2016-07-01

    Combining nonequilibrium Green's function method and density functional theory, an azulene-like dipole molecule sandwiched between two graphene nanoribbon (GNR) electrodes are explored to gas sensors. Both the pristine zigzag edged GNR and Boron-doped armchair-edged GNR are considered in this study. It shows that certain specific toxic molecules CO, NO and NO2 would adsorb on the doped Boron atoms of the GNR, resulting in a dramatic change in the current-voltage profile. Changes in the subbands of electrodes, induced by gas adsorption, are responsible for the variation of current. The devices are thus demonstrated to be sensitive nanosensors for these toxic gases.

  11. Boron-doped MnTe semiconductor-sensitized ZnO solar cells

    Indian Academy of Sciences (India)

    Auttasit Tubtimtae; Suwanna Sheangliw; Kritsada Hongsith; Supab Choopun

    2014-10-01

    We studied the photovoltaic performance of boron-doped MnTe semiconductor-sensitized solar cells (B-doped MnTe SSCs). The B-doped MnTe semiconductor was grown on ZnO using two stages of the successive ionic layer adsorption and reaction (SILAR) technique. The two phases of B-doped semiconductor nanoparticles (NPs), i.e. MnTe and MnTe2 were observed with a diameter range of approximately 15–30 nm. The result of the energy conversion efficiency of the sample with boron doping was superior compared to that of an undoped sample, due to the substantial change in the short-circuit current density and the open-circuit voltage. In addition, plots of ( ℎ )2 vs ℎ with band gaps of 1.30 and 1.27 eV were determined for the undoped and B-doped MnTe NPs, respectively. It can be noted that the boron doping effects with the change in the band gap and lead to an improvement in the crystalline quality and also intimate contact between the larger sizes of MnTe NPs. Hence, a noticeably improved photovoltaic performance resulted. However, this kind of semiconductor sensitizer can be further extended by experiments on yielding a higher power conversion efficiency and greater stability of the device.

  12. First-principles study of palladium atom adsorption on the boron- or nitrogen-doped carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Chen Guoxiang [College of Physics and Information Technology, Shaanxi Normal University, Xi' an 710062, Shaanxi (China); School of Science, Xi' an Shiyou University, Xi' an 710065, Shaanxi (China); Zhang Jianmin, E-mail: jianm_zhang@yahoo.co [College of Physics and Information Technology, Shaanxi Normal University, Xi' an 710062, Shaanxi (China); Wang Doudou [Institute of Telecommunication Engineering of the Air Force Engineering University (AFEU1), Xi' an 710077, Shaanxi (China); Xu Kewei [State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049, Shaanxi (China)

    2009-11-15

    We have performed first-principles calculation to investigate the adsorption of a single palladium atom on the surface of the pristine and boron- or nitrogen-doped carbon nanotubes (CNTs). The results show that for the adsorption of a single palladium atom on the pristine CNT surface, the most stable site is Bridge1 site above the axial carbon-carbon bond. Either boron- or nitrogen-doped CNTs can assist palladium surface adsorption, but the detailed mechanisms are different. The enhanced palladium adsorption on boron-doped CNT is attributed to the palladium d orbital strongly hybridized with both boron p orbital and carbon p orbital. The enhancement in palladium adsorption on nitrogen-doped CNT results from activating the nitrogen-neighboring carbon atoms due to the large electron affinity of nitrogen. Furthermore, the axial bond is preferred over the zigzag bond for a palladium atom adsorbed on the surface of all three types of CNTs. The most energetically favorable site for a palladium atom adsorbed on three types of CNTs is above the axial boron-carbon bond in boron-doped CNT. The enhancement in palladium adsorption is more significant for the boron-doped CNT than it is for nitrogen-doped CNT with a similar configuration. So we conclude that accordingly, the preferred adsorption site is determined by the competition between the electron affinity of doped and adsorbed atoms and preferred degree of the axial bond over the zigzag bond.

  13. Picosecond pulsed laser processing of polycrystalline diamond and cubic boron nitride composite materials

    Science.gov (United States)

    Warhanek, Maximilian G.; Pfaff, Josquin; Meier, Linus; Walter, Christian; Wegener, Konrad

    2016-03-01

    Capabilities and advantages of laser ablation processes utilizing ultrashort pulses have been demonstrated in various applications of scientific and industrial nature. Of particular interest are applications that require high geometrical accuracy, excellent surface integrity and thus tolerate only a negligible heat-affected zone in the processed area. In this context, this work presents a detailed study of the ablation characteristics of common ultrahard composite materials utilized in the cutting tool industry, namely polycrystalline diamond (PCD) and polycrystalline cubic boron nitride composite (PCBN). Due to the high hardness of these materials, conventional mechanical processing is time consuming and costly. Herein, laser ablation is an appealing solution, since no process forces and no wear have to be taken into consideration. However, an industrially viable process requires a detailed understanding of the ablation characteristics of each material. Therefore, the influence of various process parameters on material removal and processing quality at 10 ps pulse duration are investigated for several PCD and PCBN grades. The main focus of this study examines the effect of different laser energy input distributions, such as pulse frequency and burst pulses, on the processing conditions in deep cutting kerfs and the resulting processing speed. Based on these results, recommendations for efficient processing of such materials are derived.

  14. New Pathways and Metrics for Enhanced, Reversible Hydrogen Storage in Boron-Doped Carbon Nanospaces

    Energy Technology Data Exchange (ETDEWEB)

    Pfeifer, Peter [University of Missouri; Wexler, Carlos [University of Missouri; Hawthorne, M. Frederick [University of Missouri; Lee, Mark W. [University of Missouri; Jalistegi, Satish S. [University of Missouri

    2014-08-14

    This project, since its start in 2007—entitled “Networks of boron-doped carbon nanopores for low-pressure reversible hydrogen storage” (2007-10) and “New pathways and metrics for enhanced, reversible hydrogen storage in boron-doped carbon nanospaces” (2010-13)—is in support of the DOE's National Hydrogen Storage Project, as part of the DOE Hydrogen and Fuel Cells Program’s comprehensive efforts to enable the widespread commercialization of hydrogen and fuel cell technologies in diverse sectors of the economy. Hydrogen storage is widely recognized as a critical enabling technology for the successful commercialization and market acceptance of hydrogen powered vehicles. Storing sufficient hydrogen on board a wide range of vehicle platforms, at energy densities comparable to gasoline, without compromising passenger or cargo space, remains an outstanding technical challenge. Of the main three thrust areas in 2007—metal hydrides, chemical hydrogen storage, and sorption-based hydrogen storage—sorption-based storage, i.e., storage of molecular hydrogen by adsorption on high-surface-area materials (carbons, metal-organic frameworks, and other porous organic networks), has emerged as the most promising path toward achieving the 2017 DOE storage targets of 0.055 kg H2/kg system (“5.5 wt%”) and 0.040 kg H2/liter system. The objective of the project is to develop high-surface-area carbon materials that are boron-doped by incorporation of boron into the carbon lattice at the outset, i.e., during the synthesis of the material. The rationale for boron-doping is the prediction that boron atoms in carbon will raise the binding energy of hydro- gen from 4-5 kJ/mol on the undoped surface to 10-14 kJ/mol on a doped surface, and accordingly the hydro- gen storage capacity of the material. The mechanism for the increase in binding energy is electron donation from H2 to electron-deficient B atoms, in the form of sp2 boron-carbon bonds. Our team is proud to have

  15. Resonance of graphene nanoribbons doped with nitrogen and boron: a molecular dynamics study

    Directory of Open Access Journals (Sweden)

    Ye Wei

    2014-05-01

    Full Text Available Based on its enticing properties, graphene has been envisioned with applications in the area of electronics, photonics, sensors, bio-applications and others. To facilitate various applications, doping has been frequently used to manipulate the properties of graphene. Despite a number of studies conducted on doped graphene regarding its electrical and chemical properties, the impact of doping on the mechanical properties of graphene has been rarely discussed. A systematic study of the vibrational properties of graphene doped with nitrogen and boron is performed by means of a molecular dynamics simulation. The influence from different density or species of dopants has been assessed. It is found that the impacts on the quality factor, Q, resulting from different densities of dopants vary greatly, while the influence on the resonance frequency is insignificant. The reduction of the resonance frequency caused by doping with boron only is larger than the reduction caused by doping with both boron and nitrogen. This study gives a fundamental understanding of the resonance of graphene with different dopants, which may benefit their application as resonators.

  16. STURCTURAL CHARACTERISTICS AND QUANTUM CHEMISTRY CALCULATION OF Al-DOPED BORON CARBIDES

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Structural characteristics, chemical bonds and thermoelectric properties of Al-doped boron carbides are studied through calculations of various structural unit models by using a self-consistent-field discrete variation Xα method. The calculations show that Al atom doped in boron carbide is in preference to substituting B or C atoms on the end of boron carbide chain, and then may occupy interstitial sites, but it is difficult for Al to substitute B or C atom in the centers of the chain or in the icosahedra. A representative structural unit containing an Al atom is [C-B-Al]ε+-[B11C]ε-, while the structural unit without Al is [C-B-B(C)]ε--[B11C]ε+, and the coexistence of these two different structural units makes the electrical conductivity increased. As the covalent bond of Al-B or Al-C is weaker than that of B-B or B-C, the thermal conductivity decreases when Al is added into boron carbides. With the electrical conductivity increasing and the thermal conductivity decreases, Al doping has significant effect on thermoelectric properties of boron carbides.

  17. Mg-doping experiment and electrical transport measurement of boron nanobelts

    International Nuclear Information System (INIS)

    We measured electrical conductance of single crystalline boron nanobelts having α-tetragonal crystalline structure. The doping experiment of Mg was carried out by vapor diffusion method. The pure boron nanobelt is a p-type semiconductor and its electrical conductivity was estimated to be on the order of 10-3 (Ω cm)-1 at room temperature. The carrier mobility of pure boron nanobelt was measured to be on the order of 10-3 (cm2 Vs-1) at room temperature and has an activation energy of ∼0.19 eV. The Mg-doped boron nanobelts have the same α-tetragonal crystalline structure as the pristine nanobelts. After Mg vapor diffusion, the nanobelts were still semiconductor, while the electrical conductance increased by a factor of 100-500. Transition to metal or superconductor by doping was not observed. - Graphical abstract: SEM micrographs of boron nanobelt after Ni/Au electrode fabrication by electron beam lithography. Display Omitted

  18. Tuning the electronic properties of armchair carbon nanoribbons by a selective boron doping

    International Nuclear Information System (INIS)

    Armchair carbon nanoribbons (ACNRs) substitutionally doped with boron atoms are investigated in the framework of first-principles density functional theory. Different boron-boron arrangements and concentrations are considered in order to simulate possible aggregation patterns, their structural stability and electronic behavior are determined as a function of ribbon size. In agreement with previous studies, our results show that the dopant atoms have in general a preference for edge sites, but specific effects appear as a function of concentration that importantly modify the properties of the ribbons compared to the pristine case. Interesting tendencies are discovered as a function of dopant concentration that significantly affect the electronic properties of the ribbons. We have found that BC3 island formation and edge doping are the most important factors for the structural stabilization of the ribbons with high boron concentration (>7%) whereas for the cases of low boron concentrations (3 island patterns give rise to highly localized B states on top of the Fermi level, resulting in semiconducting behavior. On the other hand, when the average distance between the B atoms increases beyond island stoichiometry, the localization of their states is reduced and the ribbons may become metallic due to a band crossing caused by the lowering of the Fermi level resulting from the positive charge doping. Thus, tuning the dopant interaction would be an appropriate way to tailor the electronic properties of the ribbons in a convenient manner in view of potential technological applications.

  19. Delta-doping of boron atoms by photoexcited chemical vapor deposition

    International Nuclear Information System (INIS)

    Boron delta-doped structures in Si crystals were fabricated by means of photoexcited chemical vapor deposition (CVD). Core electronic excitation with high-energy photons ranging from vacuum ultraviolet to soft x rays decomposes B2H6 molecules into fragments. Combined with in situ monitoring by spectroscopic ellipsometry, limited number of boron hydrides can be delivered onto a Si(100) surface by using the incubation period before the formation of a solid boron film. The boron-covered surface is subsequently embedded in a Si cap layer by Si2H6 photo-excited CVD. The crystallinity of the Si cap layer depended on its thickness and the substrate temperature. The evaluation of the boron depth profile by secondary ion mass spectroscopy revealed that boron atoms were confined within the delta-doped layer at a concentration of 2.5 x 1020 cm-3 with a full width at half maximum of less than 9 nm, while the epitaxial growth of a 130-nm-thick Si cap layer was sustained at 420 deg. C.

  20. The diamond RF-transistor model

    Directory of Open Access Journals (Sweden)

    Altukhov A. A.

    2011-12-01

    Full Text Available In this work is shown that fluent shutter model it is enough well describes work field-effect diamond RF-transistors. Using this model, possible to calculate transistor parameters used electronic parameters of the diamond structure with δ-doped (hydrogen or boron layer and geometric parameter transistor element. Proof, are calculated by us main parameters model RF-transistor, which it is enough close comply with published experimental result of the measurements real RF-transistors.

  1. Boron doping compensation of hydrogenated amorphous and polymorphous germanium thin films for infrared detection applications

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, M., E-mail: mmoreno@inaoep.mx [National Institute of Astrophysics, Optics and Electronics, INAOE, P.O. Box 51 and 216, Puebla, Z. P. 72840 Puebla (Mexico); Delgadillo, N. [Universidad Autónoma de Tlaxcala, Av. Universidad No. 1, Z. P. 90006 Tlaxcala (Mexico); Torres, A. [National Institute of Astrophysics, Optics and Electronics, INAOE, P.O. Box 51 and 216, Puebla, Z. P. 72840 Puebla (Mexico); Ambrosio, R. [Technology and Engineering Institute, Ciudad Juarez University UACJ, Av. Del Charro 450N, Z. P. 32310 Chihuahua (Mexico); Rosales, P.; Kosarev, A.; Reyes-Betanzo, C.; Hidalga-Wade, J. de la; Zuniga, C.; Calleja, W. [National Institute of Astrophysics, Optics and Electronics, INAOE, P.O. Box 51 and 216, Puebla, Z. P. 72840 Puebla (Mexico)

    2013-12-02

    In this work we have studied boron doping of hydrogenated amorphous germanium a-Ge:H and polymorphous germanium (pm-Ge:H) in low regimes, in order to compensate the material from n-type (due to oxygen contamination that commonly occurs during plasma deposition) to intrinsic, and in this manner improve the properties that are important for infrared (IR) detection, as activation energy (E{sub a}) and temperature coefficient of resistance (TCR). Electrical, structural and optical characterization was performed on the films produced. Measurements of the temperature dependence of conductivity, room temperature conductivity (σ{sub RT}), E{sub a} and current–voltage characteristics under IR radiation were performed in the compensated a-Ge:H and pm-Ge:H films. Our results demonstrate that, effectively, the values of E{sub a}, TCR and IR detection are improved on the a-Ge:H/pm-Ge:H films, using boron doping in low regimes, which results of interest for infrared detectors. - Highlights: • We reported boron doping compensation of amorphous and polymorphous germanium. • The films were deposited by plasma enhanced chemical vapor deposition. • The aim is to use the films as thermo-sensing elements in un-cooled microbolometers. • Those films have advantages over boron doped a-Si:H used in commercial detectors.

  2. Platinum–boron doped graphene intercalated by carbon black for cathode catalyst in proton exchange membrane fuel cell

    International Nuclear Information System (INIS)

    In order to enhance the electrochemical properties, especially durability and cell performance in proton exchange membrane fuel cell, electron deficient boron is doped into graphene, followed by deposition of Pt nanoparticles. Successful synthesis of Pt-boron doped graphene (Pt–B–Gr) by pyrolytic process is confirmed by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and Transmission electron microscopy analyses. Pt–B–Gr is intercalated by different amount of CB (carbon black) based on Pt–B–Gr/CBx (x = 0.0, 0.2, 0.3, 0.4) and applied to cathode in proton exchange membrane fuel cell. The ECSA (electrochemical active surface area) is increased with CB content up to 30 wt.% of Pt–B–Gr from 21.4 to 33.6 m2 g−1 beyond which it is rather slightly decreased to 29.6 m2 g−1. The ADT (accelerated durability test) is conducted where the ECSA is compared at every 400 cycles up to 1200 cycles for durability. The result exhibits that boron doping into graphene significantly enhances the durability. It might be attributed to more tight binding between Pt and B due to the electron transfer from graphene to boron. The cell performance is enhanced and it is attributed to the combined effect of B-doping and intercalation. - Highlights: • Graphene was successfully doped with boron using pyrolytic process. • Pt nanoparticles were deposited onto boron-doped graphene. • Pt-boron doped graphene was intercalated by carbon black to prevent restacking. • Boron doping significantly enhanced the durability. • The combined effect of boron doping and intercalation enhanced the cell performance

  3. The Field Emission Characteristics of Titanium-Doped Nano-Diamonds

    Institute of Scientific and Technical Information of China (English)

    YANG Yan-Ning; ZHANG Zhi-Yong; ZHANG Fu-Chun; DONG Jun-Tang; ZHAO Wu; ZHAI Chun-Xue; ZHANG Wei-Hu

    2012-01-01

    An electrophoresis solution,prepared in a specific ratio of titanium (Ti)-doped nano-diamond,is dispersed by ultrasound and the nano-diamond coating is then deposited on a polished Ti substrate by electrophoresis.After high-temperature vacuum annealing,the appearance of the surface and the microstructures of the coating are observed by a metallomicroscope,scanning electron microscopy and Raman spectroscopy.The field emission characteristics and luminescence features are also tested,and the mechanism of the field emission characteristics of the Ti-doped nano-diamond is analyzed.The experimental results show that under the same conditions,the diamond-coated surface (by deposition) is more uniform after doping with 5 mg of Ti powder.Compared with the undoped nano-diamond cathode,the turn-on fields decline from 6.95 to 5.95 V/μm.When the electric field strength is 13.80 V/μm,the field emission current density increases to 130.00 μA/cm2.Under the applied fields,the emission current is stable and the luminescence is at its best,while the field emission characteristics of the 10 mg Ti-doped coating become worse,as does the luminescence.The reason for this could be that an excessive amount of TiC is generated on the surface of the coating.%An electrophoresis solution, prepared in a speciGc ratio of titanium (Ti)-doped nano-diamond, is dispersed by ultrasound and the nano-diamond coating is then deposited on a polished Ti substrate by electrophoresis. After high-temperature vacuum annealing, the appearance of the surface and the microstructures of the coating are observed by a metallomicroscope, scanning electron microscopy and Raman spectroscopy. The field emission characteristics and luminescence features are also tested, and the mechanism of the field emission characteristics of the Ti-doped nano-diamond is analyzed. The experimental results show that under the same conditions, the diamond-coated surface (by deposition) is more uniform after doping with 5 mg of Ti

  4. Cat-doping: Novel method for phosphorus and boron shallow doping in crystalline silicon at 80 °C

    Energy Technology Data Exchange (ETDEWEB)

    Matsumura, Hideki; Hayakawa, Taro; Ohta, Tatsunori; Nakashima, Yuki; Miyamoto, Motoharu; Thi, Trinh Cham; Koyama, Koichi; Ohdaira, Keisuke [Japan Advanced Institute of Science and Technology (JAIST), Asahidai, Nomi-shi, Ishikawa-ken 923-1292 (Japan)

    2014-09-21

    Phosphorus (P) or boron (B) atoms can be doped at temperatures as low as 80 to 350 °C, when crystalline silicon (c-Si) is exposed only for a few minutes to species generated by catalytic cracking reaction of phosphine (PH₃) or diborane (B₂H₆) with heated tungsten (W) catalyzer. This paper is to investigate systematically this novel doping method, “Cat-doping”, in detail. The electrical properties of P or B doped layers are studied by the Van der Pauw method based on the Hall effects measurement. The profiles of P or B atoms in c-Si are observed by secondary ion mass spectrometry mainly from back side of samples to eliminate knock-on effects. It is confirmed that the surface of p-type c-Si is converted to n-type by P Cat-doping at 80 °C, and similarly, that of n-type c-Si is to p-type by B Cat-doping. The doping depth is as shallow as 5 nm or less and the electrically activated doping concentration is 10¹⁸ to 10¹⁹cm⁻³ for both P and B doping. It is also found that the surface potential of c-Si is controlled by the shallow Cat-doping and that the surface recombination velocity of minority carriers in c-Si can be enormously lowered by this potential control.

  5. Boron diffusion into nitrogen doped silicon films for P{sup +} polysilicon gate structures

    Energy Technology Data Exchange (ETDEWEB)

    Mansour, Farida; Mahamdi, Ramdane; Jalabert, Laurent; Temple-Boyer, Pierre

    2003-06-23

    This paper deals with the study of the boron diffusion in nitrogen doped silicon (NIDOS) deposited from disilane Si{sub 2}H{sub 6} and ammonia NH{sub 3} for the development of P{sup +} polysilicon gate metal oxide semiconductor (MOS) devices. NIDOS films with varied nitrogen content have been boron implanted, then annealed and finally analysed by secondary ion mass spectroscopy (SIMS). In order to simulate the experimental SIMS of boron concentration profiles in the NIDOS films, a model adapted to the particular conditions of the samples elaboration, i.e. the very high boron concentration and the nitrogen content, has been established. The boron diffusion reduction in NIDOS films with increasing nitrogen rates has been evidenced by the profiles as well as by the obtained diffusion coefficients, which shows that the nitrogen incorporation reduces the boron diffusion. This has been confirmed by capacitance-voltage (C-V) measurements performed on MOS capacitors: the higher the nitrogen content, the lower the flat-band voltage. Finally, these results demonstrate that the improvement of the gate oxide quality occurs with the suppression of the boron penetration.

  6. Boosting the Boron Dopant Level in Monolayer Doping by Carboranes.

    Science.gov (United States)

    Ye, Liang; González-Campo, Arántzazu; Núñez, Rosario; de Jong, Michel P; Kudernac, Tibor; van der Wiel, Wilfred G; Huskens, Jurriaan

    2015-12-16

    Monolayer doping (MLD) presents an alternative method to achieve silicon doping without causing crystal damage, and it has the capability of ultrashallow doping and the doping of nonplanar surfaces. MLD utilizes dopant-containing alkene molecules that form a monolayer on the silicon surface using the well-established hydrosilylation process. Here, we demonstrate that MLD can be extended to high doping levels by designing alkenes with a high content of dopant atoms. Concretely, carborane derivatives, which have 10 B atoms per molecule, were functionalized with an alkene group. MLD using a monolayer of such a derivative yielded up to ten times higher doping levels, as measured by X-ray photoelectron spectroscopy and dynamic secondary mass spectroscopy, compared to an alkene with a single B atom. Sheet resistance measurements showed comparably increased conductivities of the Si substrates. Thermal budget analyses indicate that the doping level can be further optimized by changing the annealing conditions. PMID:26595856

  7. Structural Features of Boron-Doped Si(113) Surfaces Simulated by ab initio Calculations

    Institute of Scientific and Technical Information of China (English)

    LIAO Long-Zhong; LIU Zheng-Hui; ZHANG Zhao-Hui

    2008-01-01

    Based on ab initio calculations, boron-doped Si(113) surfaces have been simulated and atomic structures of the surfaces have been proposed. It has been determined that surface features of empty and filled states that are separately localized at pentamers and adatoms indicates a low surface density of B atoms, while it is attributed to heavy doping of B atoms at the second layer that pentamers and adatoms are both present in an image of scanning tunnelling microscopy. B doping at the second layer should be balanced by adsorbed B or Si atoms beside the adatoms and inserted B interstitials below the adatoms.

  8. Adsorption of sugars on Al- and Ga-doped boron nitride surfaces: A computational study

    Science.gov (United States)

    Darwish, Ahmed A.; Fadlallah, Mohamed M.; Badawi, Ashraf; Maarouf, Ahmed A.

    2016-07-01

    Molecular adsorption on surfaces is a key element for many applications, including sensing and catalysis. Non-invasive sugar sensing has been an active area of research due to its importance to diabetes care. The adsorption of sugars on a template surface study is at the heart of matter. Here, we study doped hexagonal boron nitride sheets (h-BNNs) as adsorbing and sensing template for glucose and glucosamine. Using first principles calculations, we find that the adsorption of glucose and glucosamine on h-BNNs is significantly enhanced by the substitutional doping of the sheet with Al and Ga. Including long range van der Waals corrections gives adsorption energies of about 2 eV. In addition to the charge transfer occurring between glucose and the Al/Ga-doped BN sheets, the adsorption alters the size of the band gap, allowing for optical detection of adsorption. We also find that Al-doped boron nitride sheet is better than Ga-doped boron nitride sheet to enhance the adsorption energy of glucose and glucosamine. The results of our work can be potentially utilized when designing support templates for glucose and glucosamine.

  9. Transport properties of boron-doped single-walled silicon carbide nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y.T. [Key laboratory of Ministry of Education for Wide Band Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi' an 710071 (China); Ding, R.X., E-mail: rx_ding@163.co [Key laboratory of Ministry of Education for Wide Band Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi' an 710071 (China); Song, J.X. [Key laboratory of Ministry of Education for Wide Band Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi' an 710071 (China); School of Electronic Engineering, Xi' an Shiyou University, Xi' an 710075 (China)

    2011-01-15

    The doped boron (B) atom in silicon carbide nanotube (SiCNT) can substitute carbon or silicon atom, forming two different structures. The transport properties of both B-doped SiCNT structures are investigated by the method combined non-equilibrium Green's function with density functional theory (DFT). As the bias ranging from 0.8 to 1.0 V, the negative differential resistance (NDR) effect occurs, which is derived from the great difficulty for electrons tunneling from one electrode to another with the increasing of localization of molecular orbital. The high similar transport properties of both B-doped SiCNT indicate that boron is a suitable impurity for fabricating nano-scale SiCNT electronic devices.

  10. Preparation of diamond-like carbon and boron nitirde films by high-intensity pulsed ion beam deposition

    Energy Technology Data Exchange (ETDEWEB)

    Rej, D.J.; Davis, H.A. [Los Alamos National Lab., NM (United States); Remnev, G.E. [Tomsk Polytechnic Univ., Tomsk (Russian Federation). Nuclear Physics Institute.] [and others

    1995-05-01

    Intense ion beams (300-keV C{sup +}, O{sup +}, and H{sup +}, 20--30 kA, 50 to 400-ns pulsewidth, up to 0.3-Hz repetition rate) were used to prepare diamond-like carbon (DLC) and boron nitride (BN) films. Deposition rates of up to 25{plus_minus}5 nm/pulse were obtained with instantaneous rates exceeding 1 mm/s. Most films were uniform, light brown, translucent, and nonporous with some micron-size particulates. Raman and parallel electron energy loss spectroscopy indicated the presence of DLC. The films possessed favorable electron field-emission characteristics desirable for cold-cathode displays. Transmission electron microscopy (TEM) and transmission electron diffraction (TED) revealed that the C films contained diamond crystals with 25 to 125-nm grain size. BN films were composed of hexagonal, cubic and wurtzite phases.

  11. Ultraviolet photosensitivity of sulfur-doped micro- and nano-crystalline diamond

    International Nuclear Information System (INIS)

    The room-temperature photosensitivity of sulfur-doped micro- (MCD), submicro- (SMCD) and nano- (NCD) crystalline diamond films synthesized by hot-filament chemical vapor deposition was studied. The structure and composition of these diamond materials were characterized by Raman spectroscopy, scanning electron microscopy and X-ray diffraction. The UV sensitivity and response time were studied for the three types of diamond materials using a steady state broad UV excitation source and two pulsed UV laser radiations. It was found that they have high sensitivity in the UV region, as high as 109 sec-1mV-1 range, linear response in a broad spectral range below 320 nm, photocurrents around ∼10-5 A, and short response time better than 100 ns, which is independent of fluency intensity. A phenomenological model was applied to help understand the role of defects and dopant concentration on the materials' photosensitivity

  12. Tuning the electronic properties of armchair carbon nanoribbons by a selective boron doping

    Energy Technology Data Exchange (ETDEWEB)

    Navarro-Santos, P; Ricardo-Chavez, J L; Lopez-Sandoval, R [Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San Jose 2055, San Luis Potosi 78216 (Mexico); Reyes-Reyes, M [Instituto de Investigacion en Comunicacion Optica, Universidad Autonoma de San Luis Potosi, Alvaro Obregon 64, San Luis Potosi 78000 (Mexico); Rivera, J L, E-mail: sandov@ipicyt.edu.m [Facultad de Ingenieria Quimica, Universidad Michoacana de San Nicolas de Hidalgo, Santiago Tapia 403, Morelia, Michoacan, 58000 (Mexico)

    2010-12-22

    Armchair carbon nanoribbons (ACNRs) substitutionally doped with boron atoms are investigated in the framework of first-principles density functional theory. Different boron-boron arrangements and concentrations are considered in order to simulate possible aggregation patterns, their structural stability and electronic behavior are determined as a function of ribbon size. In agreement with previous studies, our results show that the dopant atoms have in general a preference for edge sites, but specific effects appear as a function of concentration that importantly modify the properties of the ribbons compared to the pristine case. Interesting tendencies are discovered as a function of dopant concentration that significantly affect the electronic properties of the ribbons. We have found that BC{sub 3} island formation and edge doping are the most important factors for the structural stabilization of the ribbons with high boron concentration (>7%) whereas for the cases of low boron concentrations (<5%) the structural stabilities are similar. For all the doped cases, we have found that the BC{sub 3} island patterns give rise to highly localized B states on top of the Fermi level, resulting in semiconducting behavior. On the other hand, when the average distance between the B atoms increases beyond island stoichiometry, the localization of their states is reduced and the ribbons may become metallic due to a band crossing caused by the lowering of the Fermi level resulting from the positive charge doping. Thus, tuning the dopant interaction would be an appropriate way to tailor the electronic properties of the ribbons in a convenient manner in view of potential technological applications.

  13. Concurrent doping effect of Ti and nano-diamond on flux pinning of MgB{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Y., E-mail: yzhao@swjtu.edu.c [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Superconductivity Research Group, School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia); Ke, C. [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Cheng, C.H. [Superconductivity Research Group, School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia); Feng, Y. [Northwest Institute for Nonferrous Metal Research, P.O. Box 51, Xian, Shaanxi 710016 (China); Western Superconductivity Technology Company, Xian (China); Yang, Y. [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Munroe, P. [Superconductivity Research Group, School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia)

    2010-11-01

    Nano-diamond and titanium concurrently doped MgB{sub 2} nanocomposites have been prepared by solid state reaction method. The effects of carbon and Ti concurrent doping on J{sub c}-H behavior and pinning force scaling features of MgB{sub 2} have been investigated. Although T{sub c} was slightly depressed, J{sub c} of MgB{sub 2} have been significantly improved by the nano-diamond doping, especially in the high field region. In the mean time, the J{sub c} value in low field region is sustained though concurrent Ti doping. Microstructure analysis reveals that when nano-diamond was concurrently doped with titanium in MgB{sub 2}, a unique nanocomposite in which TiB{sub 2} forms a thin layer surrounding MgB{sub 2} grains whereas nano-diamond particles were wrapped inside the MgB{sub 2} grains. Besides, nano-diamond doping results in a high density stress field in the MgB{sub 2} samples, which may take responsibility for the {Delta}{kappa} pinning behavior in the carbon-doped MgB{sub 2} system.

  14. Seebeck coefficient and electrical conductivity of doped Beta-Boron

    International Nuclear Information System (INIS)

    Beta-rhombohedral boron (β-B) was investigated to determine its potential for use as a high temperature thermoelectric material. Single dopants to produce n or p-type material were found. The figure of merit for both types of materials is less than that of silicongermanium thermoelectric alloys

  15. Green synthesis of boron doped graphene and its application as high performance anode material in Li ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Sahoo, Madhumita; Sreena, K.P.; Vinayan, B.P.; Ramaprabhu, S., E-mail: ramp@iitm.ac.in

    2015-01-15

    Graphical abstract: Boron doped graphene (B-G), synthesized by simple hydrogen induced reduction technique using boric acid as boron precursor, have more uneven surface as a result of smaller bonding distance of boron compared to carbon, showed high capacity and high rate capability compared to pristine graphene as an anode material for Li ion battery application. - Abstract: The present work demonstrates a facile route for the large-scale, catalyst free, and green synthesis approach of boron doped graphene (B-G) and its use as high performance anode material for Li ion battery (LIB) application. Boron atoms were doped into graphene framework with an atomic percentage of 5.93% via hydrogen induced thermal reduction technique using graphite oxide and boric acid as precursors. Various characterization techniques were used to confirm the boron doping in graphene sheets. B-G as anode material shows a discharge capacity of 548 mAh g{sup −1} at 100 mA g{sup −1} after 30th cycles. At high current density value of 1 A g{sup −1}, B-G as anode material enhances the specific capacity by about 1.7 times compared to pristine graphene. The present study shows a simplistic way of boron doping in graphene leading to an enhanced Li ion adsorption due to the change in electronic states.

  16. Scale-up of B-doped diamond anode system for electrochemical oxidation of phenol simulated wastewater in batch mode

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Xiuping [Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871 (China); Ni Jinren, E-mail: nijinren@iee.pku.edu.cn [Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871 (China); Wei Junjun; Chen Pan [Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871 (China)

    2011-10-30

    Scale-up of boron-doped diamond (BDD) anode system is critical to the practical application of electrochemical oxidation in bio-refractory organic wastewater treatment. In this study, the scale-up of BDD anode system was investigated on batch-mode electrochemical oxidation of phenol simulated wastewater. It was demonstrated that BDD anode system was successfully scaled up by 121 times without performance deterioration based on the COD and specific energy consumption (E{sub sp}) models in bath mode. The COD removal rate and E{sub sp} for the scaled-up BDD anode system through enlarging the total anode area while keeping similar configuration, remained at the similar level as those before being scaled up, under the same area/volume value, current density, retention time and wastewater characteristics. The COD and E{sub sp} models used to describe the smaller BDD anode system satisfactorily predicted the performance of the scaled-up BDD anode system. Under the suitable operating conditions, the COD of phenol simulated wastewater was reduced from 540 mg l{sup -1} to 130 mg l{sup -1} within 3 h with an E{sub sp} of only 34.76 kWh m{sup -3} in the scaled-up BDD anode system. These results demonstrate that BDD anode system is very promising in practical bio-refractory organic wastewater treatment.

  17. Electronic properties of newly-discovered doped semiconductors. Superconductivity in diamond and transport properties of RuIn{sub 3}; Elektronische Eigenschaften neuer dotierter Halbleiter. Supraleitung im Diamant und Transporteigenschaften von RuIn{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Bogdanov, D.A.

    2006-08-01

    The properties of the boron-doped diamond are sensitive to the boron concentration. A semiconducting behaviour occurs at low boron concentration and transport properties are given by a hopping-mechanism. The conductivity increases for higher boron concentration. The Mott metal to insulator transition takes place at a critical boron concentration. In the metallic phase superconductivity is observed. The critical temperatures of the superconducting transition are below 3 K. In this work, the influence of boron to the electronic properties, like conductivity and magneto resistance, was studied in the vicinity of the metal to insulator transition point. The superconducting properties (critical temperature, upper critical field) were studied down to 50 mK and compared to the conventional theory of the electron-phonon coupled superconductors. The properties of polycrystalline RuIn{sub 3} are reported in few publications to be metallic. In this work single crystals of this material were grown and analysed. We observe a semiconducting behaviour with an intrinsic gap of 0.4-0.5 eV. The previously reported metallic behaviour could be interpreted in this work as influence of the elementary indium in the samples. The measurements of the specific heat at low temperatures and LDA band structure calculations confirm the semiconducting properties and the value of the semiconducting gap. (orig.)

  18. Optical patterning of trapped charge in nitrogen-doped diamond

    Science.gov (United States)

    Jayakumar, Harishankar; Henshaw, Jacob; Dhomkar, Siddharth; Pagliero, Daniela; Laraoui, Abdelghani; Manson, Neil B.; Albu, Remus; Doherty, Marcus W.; Meriles, Carlos A.

    2016-08-01

    The nitrogen-vacancy (NV) centre in diamond is emerging as a promising platform for solid-state quantum information processing and nanoscale metrology. Of interest in these applications is the manipulation of the NV charge, which can be attained by optical excitation. Here, we use two-colour optical microscopy to investigate the dynamics of NV photo-ionization, charge diffusion and trapping in type-1b diamond. We combine fixed-point laser excitation and scanning fluorescence imaging to locally alter the concentration of negatively charged NVs, and to subsequently probe the corresponding redistribution of charge. We uncover the formation of spatial patterns of trapped charge, which we qualitatively reproduce via a model of the interplay between photo-excited carriers and atomic defects. Further, by using the NV as a probe, we map the relative fraction of positively charged nitrogen on localized optical excitation. These observations may prove important to transporting quantum information between NVs or to developing three-dimensional, charge-based memories.

  19. Microfabrication, characterization and in vivo MRI compatibility of diamond microelectrodes array for neural interfacing

    Energy Technology Data Exchange (ETDEWEB)

    Hébert, Clément, E-mail: clement.hebert@cea.fr [Institut Néel, CNRS et Université Joseph Fourier, BP 166, F-38042 Grenoble Cedex 9 (France); Warnking, Jan; Depaulis, Antoine [INSERM, U836, Grenoble Institut des Neurosciences, Grenoble (France); Garçon, Laurie Amandine [Institut Néel, CNRS et Université Joseph Fourier, BP 166, F-38042 Grenoble Cedex 9 (France); CEA/INAC/SPrAM/CREAB, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Mermoux, Michel [Université Grenoble Alpes, LEPMI, F-38000 Grenoble (France); CNRS, LEPMI, F-38000 Grenoble (France); Eon, David [Institut Néel, CNRS et Université Joseph Fourier, BP 166, F-38042 Grenoble Cedex 9 (France); Mailley, Pascal [CEA-LETI-DTBS Minatec, 17 rue des Martyres, 38054 Grenoble (France); Omnès, Franck [Institut Néel, CNRS et Université Joseph Fourier, BP 166, F-38042 Grenoble Cedex 9 (France)

    2015-01-01

    Neural interfacing still requires highly stable and biocompatible materials, in particular for in vivo applications. Indeed, most of the currently used materials are degraded and/or encapsulated by the proximal tissue leading to a loss of efficiency. Here, we considered boron doped diamond microelectrodes to address this issue and we evaluated the performances of a diamond microelectrode array. We described the microfabrication process of the device and discuss its functionalities. We characterized its electrochemical performances by cyclic voltammetry and impedance spectroscopy in saline buffer and observed the typical diamond electrode electrochemical properties, wide potential window and low background current, allowing efficient electrochemical detection. The charge storage capacitance and the modulus of the electrochemical impedance were found to remain in the same range as platinum electrodes used for standard commercial devices. Finally we observed a reduced Magnetic Resonance Imaging artifact when the device was implanted on a rat cortex, suggesting that boron doped-diamond is a very promising electrode material allowing functional imaging. - Highlights: • Microfabrication of all-diamond microelectrode array • Evaluation of as-grown nanocrystalline boron-doped diamond for electrical neural interfacing • MRI compatibility of nanocrystalline boron-doped diamond.

  20. Quantum study of hydrogen interaction with plasma-facing graphite and boron doped graphite surfaces

    International Nuclear Information System (INIS)

    Hydrogen adsorption and absorption on carbon materials play an important role in plasma surface interactions in thermonuclear controlled fusion devices. The density functional theory has been used in order to investigate the interaction of hydrogen atoms with the basal (0001) plane of pure graphite and boron-doped graphite; these materials are taken as models of carbon armor of plasma facing components in tokamaks. We have shown that hydrogen adsorbs weakly on the graphite surface making the adsorbent carbon tetrahedral (sp3). It can also penetrate into the bulk through the surface aromatic cycles with a barrier of energy low compared to the energy of the impinging particles coming from the boundary plasma of tokamaks. Boron doping reinforces strongly the C-H bonding energy and decreases dramatically the energy barrier associated to hydrogen diffusion into the bulk. We have also investigated the H2 recombination on the same substrate through Eley-Rideal and Langmuir-Hinshelwood mechanisms. (authors)

  1. Communication: Towards catalytic nitric oxide reduction via oligomerization on boron doped graphene

    Science.gov (United States)

    Cantatore, Valentina; Panas, Itai

    2016-04-01

    We use density functional theory to describe a novel way for metal free catalytic reduction of nitric oxide NO utilizing boron doped graphene. The present study is based on the observation that boron doped graphene and O—N=N—O- act as Lewis acid-base pair allowing the graphene surface to act as a catalyst. The process implies electron assisted N=N bond formation prior to N—O dissociation. Two N2 + O2 product channels, one of which favoring N2O formation, are envisaged as outcome of the catalytic process. Besides, we show also that the N2 + O2 formation pathways are contrasted by a side reaction that brings to N3O3- formation and decomposition into N2O + NO2-.

  2. Boron doped ZnO embedded into reduced graphene oxide for electrochemical supercapacitors

    Science.gov (United States)

    Alver, Ü.; Tanrıverdi, A.

    2016-08-01

    In this work, reduced graphene oxide/boron doped zinc oxide (RGO/ZnO:B) composites were fabricated by a hydrothermal process and their electrochemical properties were investigated as a function of dopant concentration. First, boron doped ZnO (ZnO:B) particles was fabricated with different boron concentrations (5, 10, 15 and 20 wt%) and then ZnO:B particles were embedded into RGO sheets. The physical properties of sensitized composites were characterized by XRD and SEM. Characterization indicated that the ZnO:B particles with plate-like structure in the composite were dispersed on graphene sheets. The electrochemical properties of the RGO/ZnO:B composite were investigated through cyclic voltammetry, galvanostatic charge/discharge measurements in a 6 M KOH electrolyte. Electrochemical measurements show that the specific capacitance values of RGO/ZnO:B electrodes increase with increasing boron concentration. RGO/ZnO:B composite electrodes (20 wt% B) display the specific capacitance as high as 230.50 F/g at 5 mV/s, which is almost five times higher than that of RGO/ZnO (52.71 F/g).

  3. Copper diffusivity in boron-doped silicon wafer measured by dynamic secondary ion mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Songfoo [S.E.H (M) Sdn. Bhd., Lot 2, Lorong Enggang 35, Ulu Klang FTZ, 54200 Selangor (Malaysia); You, Ahheng [Faculty of Engineering and Technology, Multimedia University, Jalan Ayer Keroh Lama, Bukit Beruang, 75450 Melaka (Malaysia); Tou, Teckyong, E-mail: tytou@mmu.edu.my [Faculty of Engineering, Multimedia Univesity, Jalan Multimedia, 63100 Cyberjaya (Malaysia)

    2013-03-20

    Highlights: ► Effective copper diffusivity in boron-doped silicon wafer was measured. ► Dynamic secondary ion mass spectrometry was used. ► Interstitial copper ions were first drifted to surface region and allowed to back-diffuse. ► Boron concentration largely influenced the effect copper diffusivity. -- Abstract: The effective copper diffusivity (D{sub eff}) in boron-doped silicon wafer was measured using a Dynamic Secondary Ion Mass Spectrometry (D-SIMS) that was incorporated with an out-drift technique. By this technique, positive interstitial copper ions (Cu{sub I}{sup +}) migrated to the surface region when a continuous charge of electrons showered on the oxidized silicon wafer, which was also bombarded by primary O{sub 2}{sup +} ions. The Cu{sub I}{sup +} ions at the surface region diffused back to the bulk when the electron showering stopped. The D-SIMS recorded the real-time distribution of Cu{sub I}{sup +} ions, generating depth profiles for in-diffusion of copper for silicon-wafer samples with different boron concentrations. These were curve-fitted using the standard diffusion expressions to obtain different D{sub eff} values, and compared with other measurement techniques.

  4. Novel polymer composite having diamond particles and boron nitride platelets for thermal management of electric vehicle motors

    Science.gov (United States)

    Nakajima, Anri; Shoji, Atsushi; Yonemori, Kei; Seo, Nobuhide

    2016-02-01

    Thermal conductivities of silicone matrix polymers including fillers of diamond particles and/or hexagonal boron nitride (h-BN) platelets were systematically investigated in an attempt to find a thermal interface material (TIM) having high isotropic thermal conductivity and high electrical insulating ability to enable efficient heat dissipation from the motor coil ends of electric vehicles. The TIM with mixed fillers of diamond particles and h-BN platelets had a maximum thermal conductivity of 6.1 W m-1 K-1 that was almost isotropic. This is the highest value among the thermal conductivities of TIMs with silicone matrix polymer reported to date. The mechanism behind the thermal conductivity of the TIMs was also examined from the viewpoint of the change in the number of thermally conductive networks and/or a decrease in the thermal resistivity of junctions of neighboring diamond particles through the incorporation of h-BN platelets. The TIMs developed in this study will make it possible to manage the heat of electric motors and will help to popularize electric vehicles.

  5. Electrochemical treatment of reverse osmosis concentrate on boron-doped electrodes in undivided and divided cell configurations.

    Science.gov (United States)

    Bagastyo, Arseto Y; Batstone, Damien J; Kristiana, Ina; Escher, Beate I; Joll, Cynthia; Radjenovic, Jelena

    2014-08-30

    An undivided electrolytic cell may offer lower electrochlorination through reduction of chlorine/hypochlorite at the cathode. This study investigated the performance of electrooxidation of reverse osmosis concentrate using boron-doped diamond electrodes in membrane-divided and undivided cells. In both cell configurations, similar extents of chemical oxygen demand and dissolved organic carbon removal were obtained. Continuous formation of chlorinated organic compounds was observed regardless of the membrane presence. However, halogenation of the organic matter did not result in a corresponding increase in toxicity (Vibrio fischeri bioassay performed on extracted samples), with toxicity decreasing slightly until 10AhL(-1), and generally remaining near the initial baseline-toxicity equivalent concentration (TEQ) of the raw concentrate (i.e., ∼2mgL(-1)). The exception was a high range toxicity measure in the undivided cell (i.e., TEQ=11mgL(-1) at 2.4AhL(-1)), which rapidly decreased to 4mgL(-1). The discrepancy between the halogenated organic matter and toxicity patterns may be a consequence of volatile and/or polar halogenated by-products formed in oxidation by OH electrogenerated at the anode. The undivided cell exhibited lower energy compared to the divided cell, 0.25kWhgCOD(-1) and 0.34kWhgCOD(-1), respectively, yet it did not demonstrate any improvement regarding by-products formation.

  6. Effects of boron-doping on the morphology and magnetic property of carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    JIANG Qi; QIAN Lan; YI Jing; ZHU Xiaotong; ZHAO Yong

    2007-01-01

    Boron carbide nanotubes (nano-fibers) was prepared by B powder and carbon nanotubes (CNTs) at high temperature in a vacuumed quartz tube.The morphology,microstructure,component and magnetic property of samples were characterized by transmission electron microscopy (TEM),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS)and magnetic property measurement system (MPMS) controller.The results showed that B-doping CNTs have great difference in the morphology and magnetic property from those of pristine CNTs.

  7. Cu and Boron Doped Carbon Nitride for Highly Selective Oxidation of Toluene to Benzaldehyde

    Directory of Open Access Journals (Sweden)

    Hongling Han

    2015-07-01

    Full Text Available A novel Cu and boron doped graphitic carbon nitride catalyst (Cu-CNB was synthesized using cheap precursors and systematically characterized. The selective oxidation of toluene proceeded very smoothly over the catalyst at 70 °C using tert-butyl hydroperoxide (TBHP as the oxidant to exclusively afford benzaldehyde. The catalyst can be used for at least five cycles without decrease in activity and selectivity.

  8. Silicon-Based Thermoelectrics Made from a Boron-Doped Silicon Dioxide Nanocomposite

    OpenAIRE

    Snedaker, ML; Zhang, Y.; Birkel, CS; H. Wang; Day, T.; Shi, Y; Ji, X.; Kraemer, S.; Mills, CE; Moosazadeh, A; Moskovits, M.; Snyder, GJ; Stucky, GD

    2013-01-01

    We report a method for preparing p-type silicon germanium bulk alloys directly from a boron-doped silica germania nanocomposite. This is the first successful attempt to produce and characterize the thermoelectric properties of SiGe-based thermoelectric materials prepared at temperatures below the alloy's melting point through a magnesiothermic reduction of the silica-germania nanocomposite. We observe a thermoelectric power factor that is competitive with the literature record obtained for hi...

  9. Cu and Boron Doped Carbon Nitride for Highly Selective Oxidation of Toluene to Benzaldehyde.

    Science.gov (United States)

    Han, Hongling; Ding, Guodong; Wu, Tianbin; Yang, Dexin; Jiang, Tao; Han, Buxing

    2015-07-13

    A novel Cu and boron doped graphitic carbon nitride catalyst (Cu-CNB) was synthesized using cheap precursors and systematically characterized. The selective oxidation of toluene proceeded very smoothly over the catalyst at 70 °C using tert-butyl hydroperoxide (TBHP) as the oxidant to exclusively afford benzaldehyde. The catalyst can be used for at least five cycles without decrease in activity and selectivity.

  10. Boron-doped cadmium oxide composite structures and their electrochemical measurements

    Energy Technology Data Exchange (ETDEWEB)

    Lokhande, B.J., E-mail: bjlokhande@yahoo.com [Lab of Smart Mtrls Supercapacitive and Energy Studies, School of Physical Sciences, Solapur University, Solapur 413255, Maharashtra (India); Ambare, R.C. [Lab of Smart Mtrls Supercapacitive and Energy Studies, School of Physical Sciences, Solapur University, Solapur 413255, Maharashtra (India); Mane, R.S. [School of Physical Sciences, Swami Ramanand Teerth Marathwada University, Nanded 431606 (India); Bharadwaj, S.R. [Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2013-08-01

    Graphical abstract: Conducting nano-fibrous 3% boron doped cadmium oxide thin films were prepared by SILAR and its super capacitive properties were studied. - Highlights: • Samples are of nanofibrous nature. • All samples shows pseudocapacitive behavior. • 3% B doped CdO shows good specific capacitance. • 3% B doped CdO shows maximum 74.93% efficiency at 14 mA/cm{sup 2}. • 3% B doped CdO shows 0.8 Ω internal resistance. - Abstract: Boron-doped and undoped cadmium oxide composite nanostructures in thin film form were prepared onto stainless steel substrates by a successive ionic layer adsorption and reaction method using aqueous solutions of cadmium nitrate, boric acid and 1% H{sub 2}O{sub 2}. As-deposited films were annealed at 623 K for 1 h. The X-ray diffraction study shows crystalline behavior for both doped and undoped films with a porous topography and nano-wires type architecture, as observed in SEM image. Wettability test confirms the hydrophilic surface with 58° contact angle value. Estimated band gap energy is around 1.9 eV. Electrochemical behavior of the deposited films is attempted in 1 M KOH electrolyte using cyclic voltammetry (CV), electrochemical impedance spectroscopy and galvanostatic charge–discharge tests. Maximum values of the specific capacitance, specific energy and specific power obtained for 3% B doped CdO film at 2 mV/s scan rate are 20.05 F/g, 1.22 Wh/kg and 3.25 kW/kg, respectively.

  11. Effect of diborane on the microstructure of boron-doped silicon nanowires

    Science.gov (United States)

    Pan, Ling; Lew, Kok-Keong; Redwing, Joan M.; Dickey, Elizabeth C.

    2005-04-01

    Boron-doped silicon (Si) nanowires, with nominal diameters of 80 nm, were grown via the vapor-liquid-solid (VLS) mechanism using gold (Au) as a catalyst and silane (SiH 4) and diborane (B 2H 6) as precursors. The microstructure of the nanowires was studied by scanning electron microscopy, transmission electron microscopy and electron energy-loss spectroscopy. At lower B 2H 6 partial pressure and thus lower doping levels (⩽1×10 18 cm -3), most of the boron-doped Si nanowires exhibited high crystallinity. At higher B 2H 6 partial pressure (˜2×10 19 cm -3 doping level), the majority of the wires exhibited a core-shell structure with an amorphous Si shell (20-30 nm thick) surrounding a crystalline Si core. Au nanoparticles on the outer surface of the nanowires were also observed in structures grown with high B/Si gas ratios. The structural changes are believed to result from an increase in the rate of Si thin-film deposition on the outer surface of the nanowire at high B 2H 6 partial pressure, which produces the amorphous coating and also causes an instability at the liquid/solid interface resulting in a loss of Au during nanowire growth.

  12. Low-level boron doping and light-induced effects in amorphous silicon pin solar cells

    Science.gov (United States)

    Moeller, M.; Rauscher, B.; Kruehler, W.; Plaettner, R.; Pfleiderer, H.

    Amorphous silicon solar cells with the structure pin/ITO produced in the laboratory show an AM1 efficiency of up to 7.4 percent on 6 sq mm. The impact of doping the i-layer slightly with boron on the cell performance was studied together with its possible influence on the cell stability. Cells exposed to continuous AM1 illumination (up to 2000 hours) show a degradation of the efficiency. Differences in the bias-voltage during the deposition lead to significant differences in the stability whereas the influence of boron doping was not so prominent. The nu-tau-products for electrons and holes were shown to degrade differently through light-soaking for different doping-level. A further investigation was made by evaluating the frequency dependence of the capacitance via a new p i n junction model to obtain the density of states and the drift field in the i-layer for doping and light-soaking.

  13. Hydrogen doped thin film diamond. Properties and application for electronic devices

    CERN Document Server

    Looi, H J

    2000-01-01

    generation remains unknown and based on the experimental results in this work, a model is proposed. The Hall measurements conducted on this conductive layer revealed a p-type nature with promising properties for electronic device application. A more detail study based on electrical and surface science methods were carried out to identify the stability and operating conditions for this dopant. The properties of metal-semiconductor contacts on these surfaces were investigated. The fundamental knowledge is essential for exploring more advanced electronic devices such as the field effect transistors (FETs). Diamond is the only material suitable for detecting UV in the 220nm wavelength without any appreciable visible response. The prospect of introducing a doped layer based on Schottky mode for UV detection is important as it allows monolithic integration with other electronic devices. The face centered cubic allotrope of carbon, diamond, is a semiconducting material which possesses a valuable combination of extre...

  14. Osmium Atoms and Os2 Molecules Move Faster on Selenium-Doped Compared to Sulfur-Doped Boronic Graphenic Surfaces

    OpenAIRE

    Barry, Nicolas P. E.; Pitto-Barry, Anaïs; Tran, Johanna; Spencer, Simon E. F.; Johansen, Adam M.; Sanchez, Ana M.; Dove, Andrew P.; O’Reilly, Rachel K.; Deeth, Robert J; Beanland, Richard; Sadler, Peter J

    2015-01-01

    We deposited Os atoms on S- and Se-doped boronic graphenic surfaces by electron bombardment of micelles containing 16e complexes [Os(p-cymene)(1,2-dicarba-closo-dodecarborane-1,2-diselenate/dithiolate)] encapsulated in a triblock copolymer. The surfaces were characterized by energy-dispersive X-ray (EDX) analysis and electron energy loss spectroscopy of energy filtered TEM (EFTEM). Os atoms moved ca. 26× faster on the B/Se surface compared to the B/S surface (233 ± 34 pm·s–1 versus 8.9 ± 1.9 ...

  15. Growth and nucleation regimes in boron doped silicon by dynamical x-ray diffraction

    International Nuclear Information System (INIS)

    The oxygen precipitation of highly (17.5 mΩ cm) and moderately (4.5 Ω cm) boron (B) doped silicon (Si) crystals at 780 °C is investigated by following in-situ the evolution of diffraction Pendellösung oscillations. All samples show an initial diffusion-driven growth process which may change over into Ostwald ripening. For the highly doped sample and involving a nucleation step at 450 °C for 30 h, the precipitate density ρ is enhanced by a factor of 8 as compared to the moderately doped sample. The influence of a high B concentration on ρ is dramatically higher for the samples directly heated to 780 °C, where an enhancement factor of 80 is found. Considering Ostwald ripening as a second growth regime reveals consistent ripening rates and surface energies σ with those found at 900 °C in a previous publication.

  16. Growth and nucleation regimes in boron doped silicon by dynamical x-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Will, J., E-mail: johannes.will@fau.de; Gröschel, A.; Bergmann, C.; Weißer, M.; Magerl, A. [Crystallography and Structural Physics, University of Erlangen-Nürnberg, Staudtstr. 3, 91058 Erlangen (Germany)

    2014-09-15

    The oxygen precipitation of highly (17.5 mΩ cm) and moderately (4.5 Ω cm) boron (B) doped silicon (Si) crystals at 780 °C is investigated by following in-situ the evolution of diffraction Pendellösung oscillations. All samples show an initial diffusion-driven growth process which may change over into Ostwald ripening. For the highly doped sample and involving a nucleation step at 450 °C for 30 h, the precipitate density ρ is enhanced by a factor of 8 as compared to the moderately doped sample. The influence of a high B concentration on ρ is dramatically higher for the samples directly heated to 780 °C, where an enhancement factor of 80 is found. Considering Ostwald ripening as a second growth regime reveals consistent ripening rates and surface energies σ with those found at 900 °C in a previous publication.

  17. EFFECT OF SILICON DOPING IN CVD DIAMOND FILMS FROM MICROCRYSTALLINE TO NANOCRYSTALLINE ON WC-Co SUBSTRATES

    OpenAIRE

    JIANGUO ZHANG; YUXIAO CUI; BIN SHEN; FANGHONG SUN

    2013-01-01

    Si-doped diamond films with various Si concentrations are deposited on WC-Co substrates using HFCVD method, with the mixture of acetone, tetraethoxysilane (TEOS) and hydrogen as the reactant source. A variety of characterizations, including FE-SEM, AFM, Raman, XRD, surface profilometer and Rockwell indentation, are conducted to systematically investigate the influence of Si incorporation on diamond films. As the Si/C ratio from 0% to 5%, the grain size of as-deposited films decreases from 4 μ...

  18. Kinetics and thermodynamics of human serum albumin adsorption on silicon doped diamond like carbon

    International Nuclear Information System (INIS)

    To gain a better understanding of protein adsorption onto biomaterial surfaces is required for the control of biocompatibility and bioactivity. Various samples of diamond like carbon (DLC) and silicon-doped DLC were synthesised using plasma enhanced chemical vapour deposition (PECVD). The effects of surface morphology on the interaction of human serum albumin (HSA) with doped and undoped DLC films was investigated using spectroscopic ellipsometry (SE) and other surface analysis techniques. The results highlighted an increase in both contact angle and hydrophobicity with increasing silicon dopant levels. A reduction on the contact angle values. After adsorption of HSA, the films showed a reduction in the contact angle with a significant change in the cosΔ and this gap increased with increasing surface coverage of HSA. The adsorption kinetics of HSA were also investigated and revealed that the maximum adsorption occurred at pH 5.0 and the process involved chemisorption. The experimental isotherm data were analysed using the Langmuir and Freundlich‎ models. The amount of HSA adsorbed increased with contact time and reached saturation ‎after 30 min. The adsorption ‎process was found to be pseudo first order with respect to the bulk concentration and was dependent on both the concentration of protein and surface characteristics of the samples. The amount of adsorbed HSA was higher with higher levels of silicon doping of the DLC. Therefore, doping DLC may provide an approach to controlling the protein adsorption. - Graphical abstract: The average thickness layer of HSA measurement onto surfaces of DLC and Si-DLC. - Highlights: • Diamond Like Carbon (DLC) and Silicon doped DLC were synthesised and characterised. • Si-DLC increases the hydrophobicity and decreases the surface free energy. • Adsorption study using human serum albumin (HSA). • The adsorbed amount of HSA increases with increasing of Silicon content DLC. • Adsorption process follow pseudo

  19. Kinetics and thermodynamics of human serum albumin adsorption on silicon doped diamond like carbon

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Mukhtar H., E-mail: ahmed-m@email.ulster.ac.uk; Byrne, John A.; McLaughlin, James

    2015-03-15

    To gain a better understanding of protein adsorption onto biomaterial surfaces is required for the control of biocompatibility and bioactivity. Various samples of diamond like carbon (DLC) and silicon-doped DLC were synthesised using plasma enhanced chemical vapour deposition (PECVD). The effects of surface morphology on the interaction of human serum albumin (HSA) with doped and undoped DLC films was investigated using spectroscopic ellipsometry (SE) and other surface analysis techniques. The results highlighted an increase in both contact angle and hydrophobicity with increasing silicon dopant levels. A reduction on the contact angle values. After adsorption of HSA, the films showed a reduction in the contact angle with a significant change in the cosΔ and this gap increased with increasing surface coverage of HSA. The adsorption kinetics of HSA were also investigated and revealed that the maximum adsorption occurred at pH 5.0 and the process involved chemisorption. The experimental isotherm data were analysed using the Langmuir and Freundlich‎ models. The amount of HSA adsorbed increased with contact time and reached saturation ‎after 30 min. The adsorption ‎process was found to be pseudo first order with respect to the bulk concentration and was dependent on both the concentration of protein and surface characteristics of the samples. The amount of adsorbed HSA was higher with higher levels of silicon doping of the DLC. Therefore, doping DLC may provide an approach to controlling the protein adsorption. - Graphical abstract: The average thickness layer of HSA measurement onto surfaces of DLC and Si-DLC. - Highlights: • Diamond Like Carbon (DLC) and Silicon doped DLC were synthesised and characterised. • Si-DLC increases the hydrophobicity and decreases the surface free energy. • Adsorption study using human serum albumin (HSA). • The adsorbed amount of HSA increases with increasing of Silicon content DLC. • Adsorption process follow pseudo

  20. Synthesis of boron and nitrogen doped graphene supporting PtRu nanoparticles as catalysts for methanol electrooxidation

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Jiming; Zhou, Yingke, E-mail: zhouyk888@hotmail.com; Tian, Xiaohui; Xu, Xiao; Zhu, Hongxi; Zhang, Shaowei; Yuan, Tao

    2014-10-30

    Highlights: • A single-step heat treatment approach is developed to synthesize boron and nitrogen doped graphene supporting PtRu nanocatalysts. • The introduction of boron or nitrogen containing function groups into graphene can modulate the particle size and dispersion of the supporting PtRu nanoparticles. • The optimized catalysts present high electrocatalytic activity and excellent stability for methanol oxidation reaction. - Abstract: In this study, we demonstrate a single-step heat treatment approach to synthesize boron and nitrogen doped graphene supporting PtRu electrocatalysts for methanol electro-oxidation reaction. The reduction of graphene oxide, boron or nitrogen doping of graphene and loading of PtRu nanoparticles happened simultaneously during the reaction process. The morphologies and microstructures of the as-prepared catalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The electrocatalytic methanol oxidation activity and durability of the obtained catalysts were evaluated by the cyclic voltammetry and chronoamperometric techniques. The results reveal that the boron and nitrogen doped graphene supporting PtRu electrocatalysts can be successfully prepared by the single step heat treatment technique, and the introduction of boron or nitrogen containing function groups into the reduced graphene sheets could modulate the particle size and dispersion of the supporting PtRu nanoparticles and improve the electrocatalytic performance of methanol oxidation reaction. The optimal annealing temperature is 800 °C, the preferable heat treatment time is 60 min for the nitrogen-doped catalysts and 90 min for the boron-doped catalysts, and the catalysts prepared under such conditions present superior catalytic activities for methanol oxidation than those prepared under other heat treatment conditions.

  1. Synthesis of boron and nitrogen doped graphene supporting PtRu nanoparticles as catalysts for methanol electrooxidation

    International Nuclear Information System (INIS)

    Highlights: • A single-step heat treatment approach is developed to synthesize boron and nitrogen doped graphene supporting PtRu nanocatalysts. • The introduction of boron or nitrogen containing function groups into graphene can modulate the particle size and dispersion of the supporting PtRu nanoparticles. • The optimized catalysts present high electrocatalytic activity and excellent stability for methanol oxidation reaction. - Abstract: In this study, we demonstrate a single-step heat treatment approach to synthesize boron and nitrogen doped graphene supporting PtRu electrocatalysts for methanol electro-oxidation reaction. The reduction of graphene oxide, boron or nitrogen doping of graphene and loading of PtRu nanoparticles happened simultaneously during the reaction process. The morphologies and microstructures of the as-prepared catalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The electrocatalytic methanol oxidation activity and durability of the obtained catalysts were evaluated by the cyclic voltammetry and chronoamperometric techniques. The results reveal that the boron and nitrogen doped graphene supporting PtRu electrocatalysts can be successfully prepared by the single step heat treatment technique, and the introduction of boron or nitrogen containing function groups into the reduced graphene sheets could modulate the particle size and dispersion of the supporting PtRu nanoparticles and improve the electrocatalytic performance of methanol oxidation reaction. The optimal annealing temperature is 800 °C, the preferable heat treatment time is 60 min for the nitrogen-doped catalysts and 90 min for the boron-doped catalysts, and the catalysts prepared under such conditions present superior catalytic activities for methanol oxidation than those prepared under other heat treatment conditions

  2. Enhanced surface transfer doping of diamond by V{sub 2}O{sub 5} with improved thermal stability

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, Kevin G., E-mail: k.crawford.2@research.gla.ac.uk; Moran, David A. J. [School of Engineering, University of Glasgow, Glasgow G12 8LT (United Kingdom); Cao, Liang [High Magnetic Field Laboratory, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031, Anhui (China); Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, Singapore 117542 (Singapore); Qi, Dongchen, E-mail: d.qi@latrobe.edu.au [Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086 (Australia); Tallaire, Alexandre [LSPM-CNRS, Université Paris 13, Villetaneuse 93430 (France); Limiti, E.; Verona, C. [Department of Industrial Engineering, “Tor Vergata” University, Rome 00173 (Italy); Wee, Andrew T. S. [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, Singapore 117542 (Singapore)

    2016-01-25

    Surface transfer doping of hydrogen-terminated diamond has been achieved utilising V{sub 2}O{sub 5} as a surface electron accepting material. Contact between the oxide and diamond surface promotes the transfer of electrons from the diamond into the V{sub 2}O{sub 5} as revealed by the synchrotron-based high resolution photoemission spectroscopy. Electrical characterization by Hall measurement performed before and after V{sub 2}O{sub 5} deposition shows an increase in hole carrier concentration in the diamond from 3.0 × 10{sup 12} to 1.8 × 10{sup 13 }cm{sup −2} at room temperature. High temperature Hall measurements performed up to 300 °C in atmosphere reveal greatly enhanced thermal stability of the hole channel produced using V{sub 2}O{sub 5} in comparison with an air-induced surface conduction channel. Transfer doping of hydrogen-terminated diamond using high electron affinity oxides such as V{sub 2}O{sub 5} is a promising approach for achieving thermally stable, high performance diamond based devices in comparison with air-induced surface transfer doping.

  3. Tuning dissociation using isoelectronically doped graphene and hexagonal boron nitride: Water and other small molecules

    Science.gov (United States)

    Al-Hamdani, Yasmine S.; Alfè, Dario; von Lilienfeld, O. Anatole; Michaelides, Angelos

    2016-04-01

    Novel uses for 2-dimensional materials like graphene and hexagonal boron nitride (h-BN) are being frequently discovered especially for membrane and catalysis applications. Still however, a great deal remains to be understood about the interaction of environmentally and industrially relevant molecules such as water with these materials. Taking inspiration from advances in hybridising graphene and h-BN, we explore using density functional theory, the dissociation of water, hydrogen, methane, and methanol on graphene, h-BN, and their isoelectronic doped counterparts: BN doped graphene and C doped h-BN. We find that doped surfaces are considerably more reactive than their pristine counterparts and by comparing the reactivity of several small molecules, we develop a general framework for dissociative adsorption. From this a particularly attractive consequence of isoelectronic doping emerges: substrates can be doped to enhance their reactivity specifically towards either polar or non-polar adsorbates. As such, these substrates are potentially viable candidates for selective catalysts and membranes, with the implication that a range of tuneable materials can be designed.

  4. Large-Scale Sublattice Asymmetry in Pure and Boron-Doped Graphene.

    Science.gov (United States)

    Usachov, Dmitry Yu; Fedorov, Alexander V; Vilkov, Oleg Yu; Petukhov, Anatoly E; Rybkin, Artem G; Ernst, Arthur; Otrokov, Mikhail M; Chulkov, Evgueni V; Ogorodnikov, Ilya I; Kuznetsov, Mikhail V; Yashina, Lada V; Kataev, Elmar Yu; Erofeevskaya, Anna V; Voroshnin, Vladimir Yu; Adamchuk, Vera K; Laubschat, Clemens; Vyalikh, Denis V

    2016-07-13

    The implementation of future graphene-based electronics is essentially restricted by the absence of a band gap in the electronic structure of graphene. Options of how to create a band gap in a reproducible and processing compatible manner are very limited at the moment. A promising approach for the graphene band gap engineering is to introduce a large-scale sublattice asymmetry. Using photoelectron diffraction and spectroscopy we have demonstrated a selective incorporation of boron impurities into only one of the two graphene sublattices. We have shown that in the well-oriented graphene on the Co(0001) surface the carbon atoms occupy two nonequivalent positions with respect to the Co lattice, namely top and hollow sites. Boron impurities embedded into the graphene lattice preferably occupy the hollow sites due to a site-specific interaction with the Co pattern. Our theoretical calculations predict that such boron-doped graphene possesses a band gap that can be precisely controlled by the dopant concentration. B-graphene with doping asymmetry is, thus, a novel material, which is worth considering as a good candidate for electronic applications. PMID:27248659

  5. Experimental evaluation of neutron performance in boron-doped low activation concrete

    International Nuclear Information System (INIS)

    Reaction rate distribution in concrete with/without boron dopant up to a thickness of 60 cm was measured using Yayoi fast reactor located at Univ. of Tokyo. The 7 reaction rates such as 197Au(n, γ), 59Co(n, γ), 115In(n, n'), 55Mn(n, γ), 23Na(n, γ), 94Zr(n, γ) and 96Zr(n, γ) were measured at 12 different depths, and the reduction of the reaction rate as a result of boron doping was quantitatively analysed. These reaction rates were also used to determine epithermal neutron spectrum shape parameter. Monte Carlo simulations of the experimental setup were performed using the MCNP-5 code. Simulated depth profiles of reaction rates and the epithermal neutron spectrum shape parameter agreed with the experimental results with fair accuracy. This experimental results provide useful data to benchmark the accuracy of neutron transport codes in the prediction of transmission and neutron spectrum distortion in boron-doped concrete. (authors)

  6. Investigation of optical, structural and morphological properties of nanostructured boron doped TiO2 thin films

    Indian Academy of Sciences (India)

    Savaş Sönmezoǧlu; Banu Erdoǧan; İskender Askeroǧlu

    2013-12-01

    Pure and different ratios (1, 3, 5, 7 and 10%) of boron doped TiO2 thin films were grown on the glass substrate by using sol–gel dip coating method having some benefits such as basic and easy applicability compared to other thin film production methods. To investigate the effect of boron doped on the physical properties of TiO2, structural, morphological and optical properties of growth thin films were examined. 1% boron-doping has no effect on optical properties of TiO2 thin film; however, optical properties vary with > 1%. From X-ray diffraction spectra, it is seen that TiO2 thin films together with doping of boron were formed along with TiB2 hexagonal structure having (111) orientation, B2O3 cubic structure having (310) orientation, TiB0.024O2 tetragonal structure having rutile phase (110) orientation and polycrystalline structures. From SEM images, it is seen that particles together with doping of boron have homogeneously distributed and held onto surface.

  7. Nitrogen-Doped Chemical Vapour Deposited Diamond: a New Material for Room-Temperature Solid State Maser

    Institute of Scientific and Technical Information of China (English)

    N. A. Poklonski; N. M. Lapchuk; A. V. Khomich; LU Fan-Xiu; TANG Wei-Zhong; V. G. Ralchenko; I. I. Vlasov; M. V. Chukichev; Sambuu Munkhtsetseg

    2007-01-01

    Electron spin resonance (ESR) in polycrystalline diamond films grown by dc arc-jet and microwave plasma chemical vapour deposition is studied. The films with nitrogen impurity concentration up to 8 × 1018 cm-3 are also characterized by Raman, cathodoluminescence and optical absorption spectra. The ESR signal from P1 centre with g-factor of 2.0024 (nitrogen impurity atom occupying C site in diamond lattice) is found to exhibit an inversion with increasing the microwave power in an H102 resonator. The spin inversion effect could be of interest for further consideration of N-doped diamonds as a medium for masers operated at room temperature.

  8. Hole subband structure in single and double p-type {delta}-doped diamond quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Vargas, I. [Facultad de Ciencias, Univ. Autonoma del Estado de Morelos, Av. Universidad 1001, C.P. 62209, Cuernavaca (Mexico); Duque, C.A. [Inst. de Fisica, Universidad de Antioquia, AA 1226, Medellin (Colombia); Mora-Ramos, M.E. [Facultad de Ciencias, Univ. Autonoma del Estado de Morelos, Av. Universidad 1001, C.P. 62209, Cuernavaca (Mexico); Inst. de Ciencia de Materiales de Madrid, CSIC, Sor Juana Ines de la Cruz 3, 28049 Madrid (Spain); Velasco, V.R. [Inst. de Ciencia de Materiales de Madrid, CSIC, Sor Juana Ines de la Cruz 3, 28049 Madrid (Spain)

    2007-07-01

    Heavy, light, and split-off hole states in single and double p-{delta}-doped diamond quantum wells are studied with the use of a 6 x 6 k.p model. The effective mass Hamiltonian is solved using a local density Thomas-Fermi-Dirac approximation for the description of the band bending profile. The features of the valence band spectrum are briefly discussed in both cases. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Effect of sintering temperature and boron carbide content on the wear behavior of hot pressed diamond cutting segments

    Directory of Open Access Journals (Sweden)

    Islak S.

    2015-01-01

    Full Text Available The aim of this study was to investigate the effect of sintering temperature and boron carbide content on wear behavior of diamond cutting segments. For this purpose, the segments contained 2, 5 and 10 wt.% B4C were prepared by hot pressing process carried out under a pressure of 35 MPa, at 600, 650 and 700 °C for 3 minutes. The transverse rupture strength (TRS of the segments was assessed using a three-point bending test. Ankara andesite stone was cut to examine the wear behavior of segments with boron carbide. Microstructure, surfaces of wear and fracture of segments were determined by scanning electron microscopy (SEM-EDS, and X-ray diffraction (XRD analysis. As a result, the wear rate decreased significantly in the 0-5 wt.% B4C contents, while it increased in the 5-10 wt.% B4C contents. With increase in sintering temperature, the wear rate decreased due to the hard matrix.

  10. Friction and wear performance of diamond-like carbon, boron carbide, and titanium carbide coatings against glass

    International Nuclear Information System (INIS)

    Protection of glass substrates by direct ion beam deposited diamond-like carbon (DLC) coatings was observed using a commercial pin-on-disk instrument at ambient conditions without lubrication. Ion beam sputter-deposited titanium carbide and boron carbide coatings reduced sliding friction, and provided tribological protection of silicon substrates, but the improvement factor was less than that found for DLC. Observations of unlubricated sliding of hemispherical glass pins at ambient conditions on uncoated glass and silicon substrates, and ion beam deposited coatings showed decreased wear in the order: uncoated glass>uncoated silicon>boron carbide>titanium carbide>DLC>uncoated sapphire. Failure mechanisms varied widely and are discussed. Generally, the amount of wear decreased as the sliding friction decreased, with the exception of uncoated sapphire substrates, for which the wear was low despite very high friction. There is clear evidence that DLC coatings continue to protect the underlying substrate long after the damage first penetrates through the coating. The test results correlate with field use data on commercial products which have shown that the DLC coatings provide substantial extension of the useful lifetime of glass and other substrates. copyright 1997 Materials Research Society

  11. Investigation of charges carrier density in phosphorus and boron doped SiNx:H layers for crystalline silicon solar cells

    International Nuclear Information System (INIS)

    Highlights: ► We investigate the properties of phosphorus and boron-doped silicon nitride films. ► Phosphorus-doped layers yield higher lifetimes than undoped ones. ► The fixed charges density decreases when increasing the films phosphorus content. ► Boron-doped films feature very low lifetimes. ► These doped layers are of particular interest for crystalline silicon solar cells. -- Abstract: Dielectric layers are of major importance in crystalline silicon solar cells processing, especially as anti-reflection coatings and for surface passivation purposes. In this paper we investigate the fixed charge densities (Qfix) and the effective lifetimes (τeff) of phosphorus (P) and boron (B) doped silicon nitride layers deposited by plasma-enhanced chemical vapour deposition. P-doped layers exhibit a higher τeff than standard undoped layers. In contrast, B-doped layers exhibit lower τeff. A strong Qfix decrease is to be seen when increasing the P content within the film. Based on numerical simulations we also demonstrate that the passivation obtained with P- and B-doped layers are limited by the interface states rather than by the fixed charges

  12. Aluminum- and boron-co-doped ZnO ceramics: structural, morphological and electrical characterization

    Science.gov (United States)

    Liu, Shimin; Liu, Jindong; Jiang, Weiwei; Liu, Chaoqian; Ding, Wanyu; Wang, Hualin; Wang, Nan

    2016-10-01

    Highly dense and electrically conductive aluminum- and boron-co-doped ZnO (ABZO) ceramics were prepared by traditional pressureless sintering process. Single aluminum-doped ZnO (AZO) ceramics were synthesized with similar process and characterized for comparison. The densification behavior, crystal structure, morphology, composition and electrical properties of the ceramics were studied. Results indicated that AZO ceramics with the maximum relative density of 99.01 % were obtained only at 1350 °C for 4 h, which, however, was accompanied by electrical conductivity deterioration because of the increased insulated ZnAl2O4 phase formed in ceramics. Interestingly, the ABZO ceramics reached the maximum relative density of 98.84 % at 1100 °C, which was 250 °C lower compared with that of AZO ceramics. Moreover, the electrical conductivity of ABZO ceramics improved significantly with the increased sintering temperature and increased insulated ZnAl2O4 phase, which should be ascribed to the decreased grain boundaries and the resultant reduced carrier scattering in ceramics overcoming the influence of increased ZnAl2O4 phase due to boron doping effect.

  13. Bare and boron-doped cubic silicon carbide nanowires for electrochemical detection of nitrite sensitively

    Science.gov (United States)

    Yang, Tao; Zhang, Liqin; Hou, Xinmei; Chen, Junhong; Chou, Kuo-Chih

    2016-04-01

    Fabrication of eletrochemical sensors based on wide bandgap compound semiconductors has attracted increasing interest in recent years. Here we report for the first time electrochemical nitrite sensors based on cubic silicon carbide (SiC) nanowires (NWs) with smooth surface and boron-doped cubic SiC NWs with fin-like structure. Multiple techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electron energy loss spectroscopy (EELS) were used to characterize SiC and boron-doped SiC NWs. As for the electrochemical behavior of both SiC NWs electrode, the cyclic voltammetric results show that both SiC electrodes exhibit wide potential window and excellent electrocatalytic activity toward nitrite oxidation. Differential pulse voltammetry (DPV) determination reveals that there exists a good linear relationship between the oxidation peak current and the concentration in the range of 50–15000 μmoL L‑1 (cubic SiC NWs) and 5–8000 μmoL L‑1 (B-doped cubic SiC NWs) with the detection limitation of 5 and 0.5 μmoL L‑1 respectively. Compared with previously reported results, both as-prepared nitrite sensors exhibit wider linear response range with comparable high sensitivity, high stability and reproducibility.

  14. Boron-doped few-walled carbon nanotubes: novel synthesis and properties

    Science.gov (United States)

    Preston, Colin; Song, Da; Taillon, Josh; Cumings, John; Hu, Liangbing

    2016-11-01

    Few-walled carbon nanotubes offer a unique marriage of graphitic quality and robustness to ink-processing; however, doping procedures that may alter the band structure of these few-walled nanotubes are still lacking. This report introduces a novel solution-injected chemical vapor deposition growth process to fabricate the first boron-doped few-walled carbon nanotubes (B-FWNTs) reported in literature, which may have extensive applications in battery devices. A comprehensive characterization of the as-grown B-FWNTs confirms successful boron substitution in the graphitic lattice, and reveals varying growth parameters impact the structural properties of B-FWNT yield. An investigation into the optimal growth purification parameters and ink-making procedures was also conducted. This study introduces the first process technique to successfully grow intrinsically p-doped FWNTs, and provides the first investigation into the impact factors of the growth parameters, purification steps, and ink-making processes on the structural properties of the B-FWNTs and the electrical properties of the resulting spray-coated thin-film electrodes.

  15. Electrical activation in boron doped polycrystalline Si formed by sequential lateral solidification

    International Nuclear Information System (INIS)

    We have investigated the electrical activation in boron doped poly-Si using Hall measurement, 4-point probe, and secondary ion mass spectroscopy. Through doping was conducted using a mass-separated ion implanter with acceleration energies from 20 to 35 keV at doses ranging from 1 x 1015/cm2 to 4 x 1015/cm2, followed by isothermal rapid-thermal-annealing at temperatures ranging from 550 to 650 deg. C. The substrates used were poly-Si, produced by two-shot sequential lateral solidification. Reverse annealing, in which a continuous loss of charge carriers occurs, was observed in boron doped poly-Si. We found that implantation conditions play a critical role on dopant activation as well as annealing conditions. We observed that a certain implantation condition does exist where the sheet resistance is not changed upon activation annealing. Damage recovery encountered in activation annealing seems to be closely related to a reverse-annealing phenomenon. We assume that the defect-concentration profile would be more important to activation behavior of poly-Si than integrated defect-density accumulated in the silicon layer.

  16. Electrical activation in boron doped polycrystalline Si formed by sequential lateral solidification

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Won-Eui [Department of Materials Science and Engineering, Hongik University, Seoul 121-791 (Korea, Republic of); Kim, Deok Hoi; Kim, Chi Woo [LTPS Team, AMLCD Business, Samsung Mobile Display CO., Cheonan-si, ChoongchungNam-do 331-300 (Korea, Republic of); Ro, Jae-Sang, E-mail: jsang@wow.hongik.ac.kr [Department of Materials Science and Engineering, Hongik University, Seoul 121-791 (Korea, Republic of)

    2011-10-31

    We have investigated the electrical activation in boron doped poly-Si using Hall measurement, 4-point probe, and secondary ion mass spectroscopy. Through doping was conducted using a mass-separated ion implanter with acceleration energies from 20 to 35 keV at doses ranging from 1 x 10{sup 15}/cm{sup 2} to 4 x 10{sup 15}/cm{sup 2}, followed by isothermal rapid-thermal-annealing at temperatures ranging from 550 to 650 deg. C. The substrates used were poly-Si, produced by two-shot sequential lateral solidification. Reverse annealing, in which a continuous loss of charge carriers occurs, was observed in boron doped poly-Si. We found that implantation conditions play a critical role on dopant activation as well as annealing conditions. We observed that a certain implantation condition does exist where the sheet resistance is not changed upon activation annealing. Damage recovery encountered in activation annealing seems to be closely related to a reverse-annealing phenomenon. We assume that the defect-concentration profile would be more important to activation behavior of poly-Si than integrated defect-density accumulated in the silicon layer.

  17. Bare and boron-doped cubic silicon carbide nanowires for electrochemical detection of nitrite sensitively.

    Science.gov (United States)

    Yang, Tao; Zhang, Liqin; Hou, Xinmei; Chen, Junhong; Chou, Kuo-Chih

    2016-04-25

    Fabrication of eletrochemical sensors based on wide bandgap compound semiconductors has attracted increasing interest in recent years. Here we report for the first time electrochemical nitrite sensors based on cubic silicon carbide (SiC) nanowires (NWs) with smooth surface and boron-doped cubic SiC NWs with fin-like structure. Multiple techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electron energy loss spectroscopy (EELS) were used to characterize SiC and boron-doped SiC NWs. As for the electrochemical behavior of both SiC NWs electrode, the cyclic voltammetric results show that both SiC electrodes exhibit wide potential window and excellent electrocatalytic activity toward nitrite oxidation. Differential pulse voltammetry (DPV) determination reveals that there exists a good linear relationship between the oxidation peak current and the concentration in the range of 50-15000 μmoL L(-1) (cubic SiC NWs) and 5-8000 μmoL L(-1) (B-doped cubic SiC NWs) with the detection limitation of 5 and 0.5 μmoL L(-1) respectively. Compared with previously reported results, both as-prepared nitrite sensors exhibit wider linear response range with comparable high sensitivity, high stability and reproducibility.

  18. Boron

    Science.gov (United States)

    ... an eye wash. Boron was used as a food preservative between 1870 and 1920, and during World Wars ... chemical symbol), B (symbole chimique), Borate, Borate de Sodium, Borates, Bore, Boric Acid, Boric Anhydride, Boric Tartrate, ...

  19. Preparation and characterization of boron-doped titania nano-materials with antibacterial activity

    International Nuclear Information System (INIS)

    Highlights: ► B/TiO2 nano-materials are prepared and doping improves particles agglomeration. ► Absorption spectrum move to visible light after doped. ► B/TiO2 nano-materials firstly applied to the fields of antibacterial materials. ► Calcined at high temperature of 900 °C, B/TiO2 has still strong antibacterial. - Abstract: Boron-doped TiO2 (B/TiO2) nano-materials were synthesized by a sol–gel method and characterized by X-ray diffraction pattern (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrum (FT-IR) and UV–vis diffuse reflectance spectra (DRS). With the test of bacterial inhibition zone, the antibacterial properties of B/TiO2 nano-materials on Escherichia coli were investigated. The results show that the structure of TiO2 could be transformed from amorphous to anatase and then to rutile by increasing calcination temperature; part of the boron atoms probably have been weaved into the interstitial TiO2 structure or incorporated into the TiO2 lattice through occupying O sites, whereas others exist as B2O3. The results of antibacterial experiment under visible light irradiation show that the B/TiO2 nano-materials exhibit enhanced antibacterial efficiency compared with non-doped TiO2. Ultimately, the action mechanism of B/TiO2 doping is discussed.

  20. Characterization and photocatalytic activity of boron-doped TiO2 thin films prepared by liquid phase deposition technique

    Indian Academy of Sciences (India)

    Noor Shahina Begum; H M Farveez Ahmed; O M Hussain

    2008-10-01

    Boron doped TiO2 thin films have been successfully deposited on glass substrate and silicon wafer at 30°C from an aqueous solution of ammonium hexa-fluoro titanate and boron trifluoride by liquid phase deposition technique. The boric acid was used as an – scavenger. The resultant films were characterized by XRD, EDAX, UV and microstructures by SEM. The result shows the deposited film to be amorphous which becomes crystalline between 400 and 500°C. The EDAX and XRD data confirm the existence of boron atom in TiO2 matrix and a small peak corresponding to rutile phase was also found. Boron doped TiO2 thin films can be used as photocatalyst for the photodegradation of chlorobenzene which is a great environmental hazard. It was found that chlorobenzene undergoes degradation efficiently in presence of boron doped TiO2 thin films by exposing its aqueous solution to visible light. The photocatalytic activity increases with increase in the concentration of boron.

  1. Plasma Synthesized Doped Boron Nanopowder for MgB2 Superconductors

    Energy Technology Data Exchange (ETDEWEB)

    James V. Marzik

    2012-03-26

    Under this program, a process to synthesize nano-sized doped boron powder by a plasma synthesis process was developed and scaled up from 20 gram batches at program start to over 200 grams by program end. Over 75 batches of boron nanopowder were made by RF plasma synthesis. Particle sizes were typically in the 20-200 nm range. The powder was synthesized by the reductive pyrolysis of BCl{sub 3} in hydrogen in an RF plasma. A wide range of process parameters were investigated including plasma power, torch geometry, gas flow rates, and process pressure. The powder-in-tube technique was used to make monofilament and multifilament superconducting wires. MgB{sub 2} wire made with Specialty Materials plasma synthesized boron nanopowder exhibited superconducting properties that significantly exceeded the program goals. Superconducting critical currents, J{sub c}, in excess of 10{sup 5} A cm{sup -2} at magnetic fields of 8 tesla were reproducibly achieved. The upper critical magnetic field in wires fabricated with program boron powder were H{sub c2}(0) = 37 tesla, demonstrating the potential of these materials for high field magnet applications. T{sub c} in carbon-doped MgB{sub 2} powder showed a systematic decrease with increasing carbon precursor gas flows, indicating the plasma synthesis process can give precise control over dopant concentrations. Synthesis rates increased by a factor of 400% over the course of the program, demonstrating the scalability of the powder synthesis process. The plasma synthesis equipment at Specialty Materials has successfully and reproducibly made high quality boron nanopowder for MgB{sub 2} superconductors. Research and development from this program enabled Specialty Materials to successfully scale up the powder synthesis process by a factor of ten and to double the size of its powder pilot plant. Thus far the program has been a technical success. It is anticipated that continued systematic development of plasma processing parameters, dopant

  2. High quality cubic boron nitride films - A starting point for doping experiments

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Hong; Pongrac, Ivan; Wang, Xuyang; Boyen, Hans-Gerd; Ziemann, Paul [Institute of Solid State Physics, University of Ulm, D-89081 Ulm (Germany); Dohuard, Bastien; Houssiau, Laurent [LISE, University of Namur, B-5000 Namur (Belgium); Bittencourt, Carla [Materia Nova, B- 7000 Mons (Belgium)

    2007-07-01

    After the successful demonstration that c-BN films can be epitaxially grown at 900 C on top of (001)-oriented diamond substrates, such high quality samples serve as starting point for their doping with Si atoms. For this purpose, a small stripe of a Si-wafer is co-sputtered during the c-BN deposition and the resulting concentration of Si as well as of unintentionally incorporated contaminants are determined by XPS, AES for near surface concentrations and ToF-SIMS for depth profiling. These results will be related to first temperature-dependent resistance measurements.

  3. Nanoscale Control of Rewriteable Doping Patterns in Pristine Graphene/Boron Nitride Heterostructures.

    Science.gov (United States)

    Velasco, Jairo; Ju, Long; Wong, Dillon; Kahn, Salman; Lee, Juwon; Tsai, Hsin-Zon; Germany, Chad; Wickenburg, Sebastian; Lu, Jiong; Taniguchi, Takashi; Watanabe, Kenji; Zettl, Alex; Wang, Feng; Crommie, Michael F

    2016-03-01

    Nanoscale control of charge doping in two-dimensional (2D) materials permits the realization of electronic analogs of optical phenomena, relativistic physics at low energies, and technologically promising nanoelectronics. Electrostatic gating and chemical doping are the two most common methods to achieve local control of such doping. However, these approaches suffer from complicated fabrication processes that introduce contamination, change material properties irreversibly, and lack flexible pattern control. Here we demonstrate a clean, simple, and reversible technique that permits writing, reading, and erasing of doping patterns for 2D materials at the nanometer scale. We accomplish this by employing a graphene/boron nitride heterostructure that is equipped with a bottom gate electrode. By using electron transport and scanning tunneling microscopy (STM), we demonstrate that spatial control of charge doping can be realized with the application of either light or STM tip voltage excitations in conjunction with a gate electric field. Our straightforward and novel technique provides a new path toward on-demand graphene p-n junctions and ultrathin memory devices. PMID:26852622

  4. Neutral and charged boron-doped fullerenes for CO2 adsorption

    OpenAIRE

    de Silva, Suchitra W; Du, Aijun; Senadeera, Wijitha; Gu, Yuantong

    2014-01-01

    Recently, the capture and storage of CO2 have attracted research interest as a strategy to reduce the global emissions of greenhouse gases. It is crucial to find suitable materials to achieve an efficient CO2 capture. Here we report our study of CO2 adsorption on boron-doped C60 fullerene in the neutral state and in the 1e −-charged state. We use first principle density functional calculations to simulate the CO2 adsorption. The results show that CO2 can form weak interactions with the BC5...

  5. Effect of Heavily Doped Boron on Bandgap Narrowing of Strained SiGe Layers

    Institute of Scientific and Technical Information of China (English)

    YAO Fei; XUE Chun-Lai; CHENG Bu-Wen; WANG Qi-Ming

    2007-01-01

    Taking into account the compensation effect of B to Ge in strained SiGe layers for the first time, the effect of heavily doped boron on the bandgap narrowing of strained SiGe layers is calculated, and the classical Jain-Roulston (J-R) model is modified. The results show that our modified J-R model well fits the experimental values. Based on the modified J-R model, the real bandgap narrowing distribution between the conduction and valence bands is further calculated, which has great influence on modelling the electrical characteristics of SiGe heterojunction bipolar transistors.

  6. Effect of Boron-Doping on the Graphene Aerogel Used as Cathode for the Lithium-Sulfur Battery.

    Science.gov (United States)

    Xie, Yang; Meng, Zhen; Cai, Tingwei; Han, Wei-Qiang

    2015-11-18

    A porous interconnected 3D boron-doped graphene aerogel (BGA) was prepared via a one-pot hydrothermal treatment. The BGA material was first loaded with sulfur to serve as cathode in lithium-sulfur batteries. Boron was positively polarized on the graphene framework, allowing for chemical adsorption of negative polysufide species. Compared with nitrogen-doped and undoped graphene aerogel, the BGA-S cathode could deliver a higher capacity of 994 mA h g(-1) at 0.2 C after 100 cycles, as well as an outstanding rate capability, which indicated the BGA was an ideal cathode material for lithium-sulfur batteries.

  7. Adsorption Mechanism of Hydrogen on Boron-Doped Fullerenes

    Institute of Scientific and Technical Information of China (English)

    YU Liu-Min; SHI Guo-Sheng; WANG Zhi-Gang; JI Guang-Fu; LU Zhi-Peng

    2009-01-01

    The C35BH-H2 complex and two other possible isomers,C34BCαH-H2 and C34BCbH-H2,are investigated using the local-spin-density approximation (LSDA) method.The results indicate that a single hydrogen molecule could be strongly adsorbed on two isomers,C34BCaH and C34BCbH,with binding energies of 0.42 and 0.47eV,respectively,and that these calculated binding energies are suitable for reversible hydrogen adsorption/desorption near room temperature.However,it is difficult for the H2 molecule to be firmly adsorbed on C35BH.We analyze the interaction between C34BCxH (x = a,b) and the H2 molecule using dipole moments and molecular orbitals.The charge analysis showed there was a partial charge (about 0.32e)transfer from H2 to the doped fullerenes.These calculation results should broaden our understanding of the mechanisms of hydrogen storage using borondoped fullerenes.

  8. Active brazed diamond and cubic boron nitride interfacial nanostructure and application

    International Nuclear Information System (INIS)

    Active brazing is an effective technique for joining diamond or cBN grit onto metallic substrates. Current use of this technique is being made for super abrasive, high performance tools. The lecture will give an overview over different aspects such as (i) tool performance in selected applications, (ii) interfacial nanostructure between super abrasive grit and brazing alloys matrix, (iii) attempts to computer model such interface reactions and (iv) recent improvements of the abrasion resistance of the brazing alloy itself. Super abrasive tools with outstanding performance in applications such as grinding, honing or stone cutting can be manufactured by a single-layer of brazed diamond or cBN grit. A method to obtain regular grit patterns will be presented. Examples of prototype tools and their performance in different applications will be shown. The investigation of interface reactions between diamond and active brazing alloys plays an important role to further improve the brazing process and resulting tool performance. The interfacial nanostructure is characterised by a thin reaction layer of Ti with diamond and cBN, respectively. Results for Ag- and Cu-based brazing alloys will be presented and discussed in view of the influence of brazing process parameters and brazing alloy matrix. Computer modelling of the thermodynamics and kinetics of the interface reactions may allow optimising the process parameters. This requires reliable databases currently being built up. The potential of such methods in ceramic to metal joining will be described. The abrasion resistance of brazing alloys itself plays an important role for tool performance. A new method to achieve a dispersion of nano sized TiC precipitates in the alloy matrix by addition of an organic binder, decomposing during brazing will be presented. In an outlook further applications of brazed diamond grit, such as thermal management materials will be discussed. (author)

  9. Electrochemical treatment of reverse osmosis concentrate on boron-doped electrodes in undivided and divided cell configurations

    Energy Technology Data Exchange (ETDEWEB)

    Bagastyo, Arseto Y. [Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072 (Australia); Department of Environmental Engineering, Institut Teknologi Sepuluh Nopember, Surabaya 60111 (Indonesia); Batstone, Damien J. [Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072 (Australia); Kristiana, Ina [Curtin Water Quality Research Centre, Resources and Chemistry Precinct, Department of Chemistry, Curtin University, Bentley, Perth, WA 6102 (Australia); Escher, Beate I. [National Research Centre for Environmental Toxicology (Entox), The University of Queensland, Brisbane, QLD 4108 (Australia); Joll, Cynthia [Curtin Water Quality Research Centre, Resources and Chemistry Precinct, Department of Chemistry, Curtin University, Bentley, Perth, WA 6102 (Australia); Radjenovic, Jelena, E-mail: j.radjenovic@uq.edu.au [Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072 (Australia)

    2014-08-30

    Highlights: • 100% of COD and ∼70% of DOC was removed in both cell configurations. • ∼21.7 mg L{sup −1} of AOCl and ∼2.3 mg L{sup −1} of AOBr was formed regardless of the membrane use. • The TEQ was far lower than expected given the high AOCl concentrations. • The undivided cell consumed lower energy compared to the divided cell. - Abstract: An undivided electrolytic cell may offer lower electrochlorination through reduction of chlorine/hypochlorite at the cathode. This study investigated the performance of electrooxidation of reverse osmosis concentrate using boron-doped diamond electrodes in membrane-divided and undivided cells. In both cell configurations, similar extents of chemical oxygen demand and dissolved organic carbon removal were obtained. Continuous formation of chlorinated organic compounds was observed regardless of the membrane presence. However, halogenation of the organic matter did not result in a corresponding increase in toxicity (Vibrio fischeri bioassay performed on extracted samples), with toxicity decreasing slightly until 10 Ah L{sup −1}, and generally remaining near the initial baseline-toxicity equivalent concentration (TEQ) of the raw concentrate (i.e., ∼2 mg L{sup −1}). The exception was a high range toxicity measure in the undivided cell (i.e., TEQ = 11 mg L{sup −1} at 2.4 Ah L{sup −1}), which rapidly decreased to 4 mg L{sup −1}. The discrepancy between the halogenated organic matter and toxicity patterns may be a consequence of volatile and/or polar halogenated by-products formed in oxidation by OH· electrogenerated at the anode. The undivided cell exhibited lower energy compared to the divided cell, 0.25 kWh gCOD{sup −1} and 0.34 kWh gCOD{sup −1}, respectively, yet it did not demonstrate any improvement regarding by-products formation.

  10. Metal-diamond semiconductor interface and photodiode application

    International Nuclear Information System (INIS)

    Carrier transport mechanism at p-diamond/metal interfaces are studied by analyzing dependencies of specific contact resistance (ρc) on measurement temperature and acceptor concentration (NA). A variety of metals, such as Ti, Mo, Cr (carbide-forming metals), Pd, and Co (carbon-soluble metals), are deposited on boron-doped polycrystalline diamond layers, and the ρc values are measured by a transmission line method. Thermal annealing which produces metallurgical reactions between diamond and metal reduces Schottky barrier heights of the contact metals to a constant value. It is found that use of a metal compound which does not react with diamond at elevated temperatures is the key to develop the thermally stable Schottky contact material for p-diamond. Along this guideline, we test the suitability of tungsten carbide (WC) and hafnium nitride (HfN) as thermally stable Schottky contacts to develop a thermally stable, deep-ultraviolet (DUV) photodiode using a boron-doped homoepitaxial p-diamond epilayer. Thermal annealing at 500 deg. C improves the rectifying current-voltage characteristics of the photodiode, resulting in the excellent thermal stability. The discrimination ratio between DUV and visible light is measured to be as large as 106 at a reverse bias voltage as small as 2 V, and it remains almost constant after annealing at 500 deg. C for 5 h. Metal carbide and nitride contacts for diamond are thus useful for developing a thermally stable diamond DUV photodetector

  11. Complex boron redistribution kinetics in strongly doped polycrystalline-silicon/nitrogen-doped-silicon thin bi-layers

    Energy Technology Data Exchange (ETDEWEB)

    Abadli, S. [Department of Electrical Engineering, University Aout 1955, Skikda, 21000 (Algeria); LEMEAMED, Department of Electronics, University Mentouri, Constantine, 25000 (Algeria); Mansour, F. [LEMEAMED, Department of Electronics, University Mentouri, Constantine, 25000 (Algeria); Pereira, E. Bedel [CNRS-LAAS, 7 avenue du colonel Roche, 31077 Toulouse (France)

    2012-10-15

    We have investigated the complex behaviour of boron (B) redistribution process via silicon thin bi-layers interface. It concerns the instantaneous kinetics of B transfer, trapping, clustering and segregation during the thermal B activation annealing. The used silicon bi-layers have been obtained by low pressure chemical vapor deposition (LPCVD) method at 480 C, by using in-situ nitrogen-doped-silicon (NiDoS) layer and strongly B doped polycrystalline-silicon (P{sup +}) layer. To avoid long-range B redistributions, thermal annealing was carried out at relatively low-temperatures (600 C and 700 C) for various times ranging between 30 min and 2 h. To investigate the experimental secondary ion mass spectroscopy (SIMS) doping profiles, a redistribution model well adapted to the particular structure of two thin layers and to the effects of strong-concentrations has been established. The good adjustment of the simulated profiles with the experimental SIMS profiles allowed a fundamental understanding about the instantaneous physical phenomena giving and disturbing the complex B redistribution profiles-shoulders. The increasing kinetics of the B peak concentration near the bi-layers interface is well reproduced by the established model. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Complex Boron Redistribution in P+ Doped-polysilicon / Nitrogen Doped Silicon Bi-layers during Activation Annealing

    Science.gov (United States)

    Abadli, S.; Mansour, F.; Perrera, E. Bedel

    We have investigated and modeled the complex phenomenon of boron (B) redistribution process in strongly doped silicon bilayers structure. A one-dimensional two stream transfer model well adapted to the particular structure of bi- layers and to the effects of strong-concentrations has been developed. This model takes into account the instantaneous kinetics of B transfer, trapping, clustering and segregation during the thermal B activation annealing. The used silicon bi-layers have been obtained by low pressure chemical vapor deposition (LPCVD) method, using in-situ nitrogen- doped-silicon (NiDoS) layer and strongly B doped polycrystalline-silicon (P+) layer. To avoid long redistributions, thermal annealing was carried out at relatively lowtemperatures (600 °C and 700 °C) for various times ranging between 30 minutes and 2 hours. The good adjustment of the simulated profiles with the experimental secondary ion mass spectroscopy (SIMS) profiles allowed a fundamental understanding about the instantaneous physical phenomena giving and disturbing the complex B redistribution profiles-shoulders kinetics.

  13. Defect charge states in Si doped hexagonal boron-nitride monolayer.

    Science.gov (United States)

    Mapasha, R E; Molepo, M P; Andrew, R C; Chetty, N

    2016-02-10

    We perform ab initio density functional theory calculations to investigate the energetics, electronic and magnetic properties of isolated stoichiometric and non-stoichiometric substitutional Si complexes in a hexagonal boron-nitride monolayer. The Si impurity atoms substituting the boron atom sites SiB giving non-stoichiometric complexes are found to be the most energetically favourable, and are half-metallic and order ferromagnetically in the neutral charge state. We find that the magnetic moments and magnetization energies increase monotonically when Si defects form a cluster. Partial density of states and standard Mulliken population analysis indicate that the half-metallic character and magnetic moments mainly arise from the Si 3p impurity states. The stoichiometric Si complexes are energetically unfavorable and non-magnetic. When charging the energetically favourable non-stoichiometric Si complexes, we find that the formation energies strongly depend on the impurity charge states and Fermi level position. We also find that the magnetic moments and orderings are tunable by charge state modulation q  =  -2, -1, 0, +1, +2. The induced half-metallic character is lost (retained) when charging isolated (clustered) Si defect(s). This underlines the potential of a Si doped hexagonal boron-nitride monolayer for novel spin-based applications.

  14. Hydrogen storage in Li-doped fullerene-intercalated hexagonal boron nitrogen layers

    Science.gov (United States)

    Cheng, Yi-Han; Zhang, Chuan-Yu; Ren, Juan; Tong, Kai-Yu

    2016-10-01

    New materials for hydrogen storage of Li-doped fullerene (C20, C28, C36, C50, C60, C70)-intercalated hexagonal boron nitrogen ( h-BN) frameworks were designed by using density functional theory (DFT) calculations. First-principles molecular dynamics (MD) simulations showed that the structures of the C n -BN ( n = 20, 28, 36, 50, 60, and 70) frameworks were stable at room temperature. The interlayer distance of the h-BN layers was expanded to 9.96-13.59 Å by the intercalated fullerenes. The hydrogen storage capacities of these three-dimensional (3D) frameworks were studied using grand canonical Monte Carlo (GCMC) simulations. The GCMC results revealed that at 77 K and 100 bar (10 MPa), the C50-BN framework exhibited the highest gravimetric hydrogen uptake of 6.86 wt% and volumetric hydrogen uptake of 58.01 g/L. Thus, the hydrogen uptake of the Li-doped C n -intercalated h-BN frameworks was nearly double that of the non-doped framework at room temperature. Furthermore, the isosteric heats of adsorption were in the range of 10-21 kJ/mol, values that are suitable for adsorbing/desorbing the hydrogen molecules at room temperature. At 193 K (-80 °C) and 100 bar for the Li-doped C50-BN framework, the gravimetric and volumetric uptakes of H2 reached 3.72 wt% and 30.08 g/L, respectively.

  15. Iron-boron pairing kinetics in illuminated p-type and in boron/phosphorus co-doped n-type silicon

    Energy Technology Data Exchange (ETDEWEB)

    Möller, Christian, E-mail: cmoeller@cismst.de [CiS Forschungsinstitut für Mikrosensorik und Photovoltaik GmbH, Konrad-Zuse-Str. 14, 99099 Erfurt (Germany); TU Ilmenau, Institut für Physik, Weimarer Str. 32, 98693 Ilmenau (Germany); Bartel, Til; Gibaja, Fabien [Calisolar GmbH, Magnusstraße 11, 12489 Berlin (Germany); Lauer, Kevin [CiS Forschungsinstitut für Mikrosensorik und Photovoltaik GmbH, Konrad-Zuse-Str. 14, 99099 Erfurt (Germany)

    2014-07-14

    Iron-boron (FeB) pairing is observed in the n-type region of a boron and phosphorus co-doped silicon sample which is unexpected from the FeB pair model of Kimerling and Benton. To explain the experimental data, the existing FeB pair model is extended by taking into account the electronic capture and emission rates at the interstitial iron (Fe{sub i}) trap level as a function of the charge carrier densities. According to this model, the charge state of the Fe{sub i} may be charged in n-type making FeB association possible. Further, FeB pair formation during illumination in p-type silicon is investigated. This permits the determination of the charge carrier density dependent FeB dissociation rate and in consequence allows to determine the acceptor concentration in the co-doped n-type silicon by lifetime measurement.

  16. Bacterial attachment and removal properties of silicon- and nitrogen-doped diamond-like carbon coatings.

    Science.gov (United States)

    Zhao, Qi; Su, Xueju; Wang, Su; Zhang, Xiaoling; Navabpour, Parnia; Teer, Dennis

    2009-01-01

    Si- and N-doped diamond-like carbon (DLC) coatings with various Si and N contents were deposited on glass slides using magnetron sputter ion-plating and plasma-enhanced chemical vapour deposition. Surface energy analysis of the DLC coatings revealed that with increasing Si content, the electron acceptor gamma(s)(+) value decreased while the electron donor gamma(s)(-) value increased. The antifouling property of DLC coatings was evaluated with the bacterium, Pseudomonas fluorescens, which is one of the most common microorganisms forming biofilms on the surface of heat exchangers in cooling water systems. P. fluorescens had a high value of the gamma(s)(-) component (69.78 mN m(-1)) and a low value of the gamma(s)(+) component (5.97 mN m(-1)), and would be negatively charged with the zeta potential of -16.1 mV. The experimental results showed that bacterial removal by a standardised washing procedure increased significantly with increasing electron donor gamma(s)(-) values and with decreasing electron acceptor gamma(s)(+) values of DLC coatings. The incorporation of 2%N into the Si-doped DLC coatings further significantly reduced bacterial attachment and significantly increased ease of removal. The best Si-N-doped DLC coatings reduced bacterial attachment by 58% and increased removal by 41%, compared with a silicone coating, Silastic T2. Bacterial adhesion strength on the DLC coatings is explained in terms of thermodynamic work of adhesion. PMID:19283517

  17. Pros and cons of nickel- and boron-doping to study helium effects in ferritic/martensitic steels

    Science.gov (United States)

    Hashimoto, N.; Klueh, R. L.; Shiba, K.

    2002-12-01

    In the absence of a 14 MeV neutron source, the effect of helium on structural materials for fusion must be simulated using fission reactors. Helium effects in ferritic/martensitic steels have been studied by adding nickel and boron and irradiating in a mixed-spectrum reactor. Although the nickel- and boron-doping techniques have limitations and difficulties to estimate helium effects on the ferritic/martensitic steels, past irradiation experiments using these techniques have demonstrated similar effects on the swelling and Charpy impact properties that are indicative of a helium effect. Although both techniques have disadvantages, it should be possible to plan experiments using the nickel- and boron-doping techniques to develop an understanding of the effects of helium on mechanical properties.

  18. Boron-doped graphene as promising support for platinum catalyst with superior activity towards the methanol electrooxidation reaction

    Science.gov (United States)

    Sun, Yongrong; Du, Chunyu; An, Meichen; Du, Lei; Tan, Qiang; Liu, Chuntao; Gao, Yunzhi; Yin, Geping

    2015-12-01

    We report the synthesis of boron-doped graphene by thermally annealing the mixture of graphene oxide and boric acid, and its usage as the support of Pt catalyst towards the methanol oxidation reaction. The composition, structure and morphology of boron-doped graphene and its supported Pt nanoparticles (Pt/BG) are characterized by transmission electron microscopy, inductively coupled plasma mass spectrometry, Raman spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. It is revealed that boron atoms are doped into graphene network in the form of BC2O and BCO2 bonds, which lead to the increase in defect sites and facilitate the subsequent deposition of Pt nanoparticles. Therefore, the Pt/BG catalyst presents smaller particle size and narrower size distribution than the graphene supported Pt (Pt/G) catalyst. When evaluated as the electrocatalyst for the methanol oxidation reaction, the Pt/BG catalyst exhibits excellent electrochemical activity and stability demonstrated by cyclic voltammetry and chronoamperometry tests. The enhanced activity is mainly ascribed to the electronic interaction between boron-doped graphene and Pt nanoparticles, which lowers the d-band center of Pt and thus weakens the absorption of the poisoning intermediate CO. Our work provides an alternative approach of improving the reaction kinetics for the oxidation of small organic molecules.

  19. Synthesis and characterization of boron-doped NiO thin films pro-duced by spray pyrolysis

    Institute of Scientific and Technical Information of China (English)

    U Alver; H Yaykasl; S Kerli; A Tanrverdi

    2013-01-01

    Boron-doped NiO thin films were prepared on glass substrates at 400◦C by airbrush spraying method using a solution of nickel nitrate hexahydrate. Their physical properties were investigated as a function of dopant concentration. From X-ray diff raction patterns, it is observed that the films have cubic structure with lattice parameters varying with boron concentration. The morphologies of the films were examined by using scanning electron microscopy, and the grain sizes were measured to be around 30-50 nm. Optical measurements show that the band gap energies of the films first decrease then increase with increasing boron concentration. The resistivities of the films were determined by four point probe method, and the changes in resistivity with boron concentration were investigated.

  20. Effect of Silicon Doping in Cvd Diamond Films from Microcrystalline to Nanocrystalline on WC-Co Substrates

    Science.gov (United States)

    Zhang, Jianguo; Cui, Yuxiao; Shen, Bin; Sun, Fanghong

    2013-12-01

    Si-doped diamond films with various Si concentrations are deposited on WC-Co substrates using HFCVD method, with the mixture of acetone, tetraethoxysilane (TEOS) and hydrogen as the reactant source. A variety of characterizations, including FE-SEM, AFM, Raman, XRD, surface profilometer and Rockwell indentation, are conducted to systematically investigate the influence of Si incorporation on diamond films. As the Si/C ratio from 0% to 5%, the grain size of as-deposited films decreases from 4 μm to about 50 nm, and the surface roughness reduces from Ra 290 nm to Ra 180 nm. Besides, the intensity ratio of I(111)/I(220) varies from 0.57 to 0, indicating the preferred orientation of the nanocrystalline structure in the 5% doped diamond films. The silicon doping is beneficial for the formation of non-diamond carbide phases in the films, according to the Raman spectra. Moreover, the film adhesion is also improved with the increase of Si/C ratio.

  1. Stress reduction of Cu-doped diamond-like carbon films from ab initio calculations

    Directory of Open Access Journals (Sweden)

    Xiaowei Li

    2015-01-01

    Full Text Available Structure and properties of Cu-doped diamond-like carbon films (DLC were investigated using ab initio calculations. The effect of Cu concentrations (1.56∼7.81 at.% on atomic bond structure was mainly analyzed to clarify the residual stress reduction mechanism. Results showed that with introducing Cu into DLC films, the residual compressive stress decreased firstly and then increased for each case with the obvious deterioration of mechanical properties, which was in agreement with the experimental results. Structural analysis revealed that the weak Cu-C bond and the relaxation of both the distorted bond angles and bond lengths accounted for the significant reduction of residual compressive stress, while at the higher Cu concentration the increase of residual stress attributed to the existence of distorted Cu-C structures and the increased fraction of distorted C-C bond lengths.

  2. Investigation of Physical Properties and Electrochemical Behavior of Nitrogen-Doped Diamond-Like Carbon Thin Films

    Directory of Open Access Journals (Sweden)

    Rattanakorn Saensak

    2014-03-01

    Full Text Available This work reports characterizations of diamond-like carbon (DLC films used as electrodes for electrochemical applications. DLC thin films are prepared on glass slides and silicon substrates by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD using a gas mixture of methane and hydrogen. In addition, the DLC films are doped with nitrogen in order to reduce electrical resistivity. Compared to the undoped DLC films, the electrical resistivity of nitrogen-doped (N-doped DLC films is decreased by three orders of magnitude. Raman spectroscopy and UV/Vis spectroscopy analyses show the structural transformation in N-doped DLC films that causes the reduction of band gap energy. Contact angle measurement at N-doped DLC films indicates increased hydrophobicity. The results obtained from the cyclic voltammetry measurements with Fe(CN63-/Fe(CN64- redox species exhibit the correlation between the physical properties and electrochemical behavior of DLC films.

  3. Determination of active doping in highly resistive boron doped silicon nanocrystals embedded in SiO{sub 2} by capacitance voltage measurement on inverted metal oxide semiconductor structure

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Tian, E-mail: tianz@student.unsw.edu.au; Puthen-Veettil, Binesh; Wu, Lingfeng; Jia, Xuguang; Lin, Ziyun; Yang, Terry Chien-Jen; Conibeer, Gavin; Perez-Wurfl, Ivan [Australian Centre for Advanced Photovoltaics, UNSW Australia, Kensington, New South Wales 2052 (Australia)

    2015-10-21

    We investigate the Capacitance-Voltage (CV) measurement to study the electrically active boron doping in Si nanocrystals (ncSi) embedded in SiO{sub 2}. The ncSi thin films with high resistivity (200–400 Ω cm) can be measured by using an inverted metal oxide semiconductor (MOS) structure (Al/ncSi (B)/SiO{sub 2}/Si). This device structure eliminates the complications from the effects of lateral current flow and the high sheet resistance in standard lateral MOS structures. The characteristic MOS CV curves observed are consistent with the effective p-type doping. The CV modeling method is presented and used to evaluate the electrically active doping concentration. We find that the highly boron doped ncSi films have electrically active doping of 10{sup 18}–10{sup 19 }cm{sup −3} despite their high resistivity. The saturation of doping at about 1.4 × 10{sup 19 }cm{sup −3} and the low doping efficiency less than 5% are observed and discussed. The calculated effective mobility is in the order of 10{sup −3} cm{sup 2}/V s, indicating strong impurity/defect scattering effect that hinders carriers transport.

  4. Determination of active doping in highly resistive boron doped silicon nanocrystals embedded in SiO2 by capacitance voltage measurement on inverted metal oxide semiconductor structure

    International Nuclear Information System (INIS)

    We investigate the Capacitance-Voltage (CV) measurement to study the electrically active boron doping in Si nanocrystals (ncSi) embedded in SiO2. The ncSi thin films with high resistivity (200–400 Ω cm) can be measured by using an inverted metal oxide semiconductor (MOS) structure (Al/ncSi (B)/SiO2/Si). This device structure eliminates the complications from the effects of lateral current flow and the high sheet resistance in standard lateral MOS structures. The characteristic MOS CV curves observed are consistent with the effective p-type doping. The CV modeling method is presented and used to evaluate the electrically active doping concentration. We find that the highly boron doped ncSi films have electrically active doping of 1018–1019 cm−3 despite their high resistivity. The saturation of doping at about 1.4 × 1019 cm−3 and the low doping efficiency less than 5% are observed and discussed. The calculated effective mobility is in the order of 10−3 cm2/V s, indicating strong impurity/defect scattering effect that hinders carriers transport

  5. Stabilizing shallow color centers in diamond created by nitrogen delta-doping using SF6 plasma treatment

    International Nuclear Information System (INIS)

    Here we report the fabrication of stable, shallow (<5 nm) nitrogen-vacancy (NV) centers in diamond by nitrogen delta doping at the last stage of the chemical vapor deposition growth process. The NVs are stabilized after treating the diamond in SF6 plasma, otherwise the color centers are not observed, suggesting a strong influence from the surface. X-ray photoelectron spectroscopy measurements show the presence of only fluorine atoms on the surface, in contrast to previous studies, indicating very good surface coverage. We managed to detect hydrogen nuclear magnetic resonance signal from protons in the immersion oil, revealing a depth of the NVs of about 5 nm

  6. Conductivity and superconductivity in heavily vacant diamond

    Directory of Open Access Journals (Sweden)

    S A Jafari

    2009-08-01

    Full Text Available   Motivated by the idea of impurity band superconductivity in heavily Boron doped diamond, we investigate the doping of various elements into diamond to address the question, which impurity band can offer a better DOS at the Fermi level. Surprisingly, we find that the vacancy does the best job in producing the largest DOS at the Fermi surface. To investigate the effect of disorder in Anderson localization of the resulting impurity band, we use a simple tight-binding model. Our preliminary study based on the kernel polynomial method shows that the impurity band is already localized at the concentration of 10-3. Around the vacancy concentration of 0.006 the whole spectrum of diamond becomes localized and quantum percolation takes place. Therefore to achieve conducting bands at concentrations on the scale of 5-10 percent, one needs to introduce correlations such as hopping among the vacancies .

  7. Investigation on cubic boron nitride crystals doped with Si by high temperature thermal diffusion

    Science.gov (United States)

    Li, Xinlu; Feng, Shuang; Liu, Xiuhuan; Hou, Lixin; Gao, Yanjun; Wang, Qi; Liu, Nian; Zhang, Hai; Chen, Zhanguo; Zheng, Jie; Jia, Gang

    2014-07-01

    The method of high temperature thermal diffusion was successfully applied for doping Si impurities into cubic boron nitride (cBN) crystals. X-ray photoelectron spectra (XPS) and the current-voltage (I-V) characteristics at different temperatures were respectively used for analyzing the chemical states and the activation energy of Si impurity in cBN. According to the XPS results, Si impurities mainly replace B atoms bonding with the adjacent N atoms and become donors in cBN. Without surface cleaning, there are a lot of C and O contaminations on the surface of cBN, so a small quantity of C-Si and Si-N-O bonds also exist at the surface of cBN. Most Si impurities distribute in the shallow layer underneath the surface of cBN. Based on the electric measurement, Si impurities in cBN usually have the activation energy beyond 0.4 eV, and they can only be slightly ionized at room temperature, therefore the resistivity of Si-doped cBN is still high, and the space charge limited current becomes the main conductive mechanism in cBN. However, the conductivity of Si-doped cBN can rapidly increase with the temperature. In addition, the activation energy and the concentration of Si impurity in cBN can be affected by the temperature and the time of thermal diffusion, which needs to be verified further.

  8. Effects of domain size on x-ray absorption spectra of boron nitride doped graphenes

    Science.gov (United States)

    Li, Xin; Hua, Weijie; Wang, Bo-Yao; Pong, Way-Faung; Glans, Per-Anders; Guo, Jinghua; Luo, Yi

    2016-08-01

    Doping is an efficient way to open the zero band gap of graphene. The control of the dopant domain size allows us to tailor the electronic structure and the properties of the graphene. We have studied the electronic structure of boron nitride doped graphenes with different domain sizes by simulating their near-edge X-ray absorption fine structure (NEXAFS) spectra at the N K-edge. Six different doping configurations (five quantum dot type and one phase-separated zigzag-edged type) were chosen, and N K-edge NEXAFS spectra were calculated with large truncated cluster models by using the density functional theory with hybrid functional and the equivalent core hole approximation. The opening of the band gap as a function of the domain size is revealed. We found that nitrogens in the dopant boundary contribute a weaker, red-shifted π* peak in the spectra as compared to those in the dopant domain center. The shift is related to the fact that these interfacial nitrogens dominate the lowest conduction band of the system. Upon increasing the domain size, the ratio of interfacial atom decreases, which leads to a blue shift of the π* peak in the total NEXAFS spectra. The spectral evolution agrees well with experiments measured at different BN-dopant concentrations and approaches to that of a pristine h-BN sheet.

  9. Boron Doped Multi-walled Carbon Nanotubes as Catalysts for Oxygen Reduction Reaction and Oxygen Evolution Reactionin in Alkaline Media

    International Nuclear Information System (INIS)

    The boron doped multi-walled carbon nanotubes (B-MWCNTs) were synthesized by thermal annealing multi-walled carbon nanotubes (MWCNTs) in the presence of boric acid. The transmission electron microscopy (TEM) and X-ray diffraction (XRD) results revealed that the structure of MWCNTs does not be destroyed during the doping process, and X-ray photoelectron spectroscopy (XPS) analysis demonstrated the boron atoms were successfully doped in the structure of MWCNTs. The electrocatalytic properties of B-MWCNTs are characterized by rotating disk electrode (RDE) methods. The results demonstrated that the B-MWCNTs catalyzed oxygen reduction reaction (ORR) in alkaline media by a 2 + 2 electron pathway and it showed good catalytic activity for oxygen evolution reaction (OER) as well

  10. Science Letters:Development of supported boron-doping TiO2 catalysts by chemical vapor deposition

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this study, supported nonmetal (boron) doping TiO2 coating photocatalysts were prepared by chemical vapor deposition (CVD) to enhance the activity under visible light irradiation and avoid the recovering of TiO2. Boron atoms were successfully doped into the lattice of TiO2 through CVD, as evidenced from XPS analysis. B-doped TiO2 coating catalysts showed drastic and strong absorption in the visible light range with a red shift in the band gap transition. This novel B-TiO2 coating photocatalyst showed higher photocatalytic activity in methyl orange degradation under visible light irradiation than that of the pure TiO2 photocatalyst.

  11. Temperature dependent simulation of diamond depleted Schottky PIN diodes

    Science.gov (United States)

    Hathwar, Raghuraj; Dutta, Maitreya; Koeck, Franz A. M.; Nemanich, Robert J.; Chowdhury, Srabanti; Goodnick, Stephen M.

    2016-06-01

    Diamond is considered as an ideal material for high field and high power devices due to its high breakdown field, high lightly doped carrier mobility, and high thermal conductivity. The modeling and simulation of diamond devices are therefore important to predict the performances of diamond based devices. In this context, we use Silvaco® Atlas, a drift-diffusion based commercial software, to model diamond based power devices. The models used in Atlas were modified to account for both variable range and nearest neighbor hopping transport in the impurity bands associated with high activation energies for boron doped and phosphorus doped diamond. The models were fit to experimentally reported resistivity data over a wide range of doping concentrations and temperatures. We compare to recent data on depleted diamond Schottky PIN diodes demonstrating low turn-on voltages and high reverse breakdown voltages, which could be useful for high power rectifying applications due to the low turn-on voltage enabling high forward current densities. Three dimensional simulations of the depleted Schottky PIN diamond devices were performed and the results are verified with experimental data at different operating temperatures

  12. Thin film diamond. Electronic devices for high temperature, high power and high radiation applications

    International Nuclear Information System (INIS)

    In the ideal form diamond displays extreme physical, optical and electronic properties, making this material interesting for many device applications. However, natural or high pressure, high temperature synthesised forms of diamond are not useful since they are only available as small irregular crystallites and are expensive. The emergence of commercially accessible techniques for the formation of thin films of diamond over relatively large areas has changed this situation, enabling the prospects for the use of diamond as an electronic material to be truly evaluated. Thin film diamond is a defective polycrystalline material. It is difficult to dope n- and p-type and resists conventional chemical etching. Thus, despite the superlative properties of ideal diamond, the realisation of useful devices from this material is far from simple. This thesis considers how the problems may be overcome such that high performance diamond devices can be realised for use in high temperature, high power and high radiation environments. Following a review of the current state-of-the-art in diamond device technology the experimental techniques used throughout this study are summarised. Field effect transistors (FETs) have been designed for operation at high (>300 deg. C) temperatures. Boron-doped (p-type) diamond was used to form the active channel, with insulating diamond acting as the gate to the FET structure. Polycrystalline diamond devices with the highest yet reported transconductance values, which display full turn-off characteristics have been produced. To enable room temperature operation, where boron is an ineffective dopant, a novel doping approach has been established using hydrogen; devices with transconductance, power handling and full pinch-off characteristic have been realised for the first time with this approach. More complex devices require patterning of the diamond substrate material; reactive ion etching using oxygen and chlorinated fluorocarbons have been studied

  13. The influence of boron content on electroanalytical detection of nitrate using BDD electrodes

    Science.gov (United States)

    Matsushima, J. T.; Silva, W. M.; Azevedo, A. F.; Baldan, M. R.; Ferreira, N. G.

    2009-11-01

    Electrochemical response of nitrate reduction was analyzed using Boron Doped Diamond (BDD) films grown with different boron levels and it was correlated with the electrode physico-chemical properties. X-ray photoelectron spectroscopy and contact angle measurements showed the evolution of oxygen content and the weattability associated to the chemical surface modification as boron content increase in such films. Raman spectroscopy showed that the broad peaks at 1220 and 500 cm -1 become more evident with the boron addition. Electrochemical measurements by square wave voltammetry for nitrate reduction showed a strong dependence between the doping level of the BDD film and the nitrate detection. BDD film grown with B/C ratio of 20,000 ppm presented the best sensibility to low concentration of nitrate. This result was analyzed from the linear relationship between the peak currents as a function of the nitrate concentration. This behavior was attributed to the changes in the diamond surface chemical and the film grain size.

  14. The influence of boron content on electroanalytical detection of nitrate using BDD electrodes

    International Nuclear Information System (INIS)

    Electrochemical response of nitrate reduction was analyzed using Boron Doped Diamond (BDD) films grown with different boron levels and it was correlated with the electrode physico-chemical properties. X-ray photoelectron spectroscopy and contact angle measurements showed the evolution of oxygen content and the weattability associated to the chemical surface modification as boron content increase in such films. Raman spectroscopy showed that the broad peaks at 1220 and 500 cm-1 become more evident with the boron addition. Electrochemical measurements by square wave voltammetry for nitrate reduction showed a strong dependence between the doping level of the BDD film and the nitrate detection. BDD film grown with B/C ratio of 20,000 ppm presented the best sensibility to low concentration of nitrate. This result was analyzed from the linear relationship between the peak currents as a function of the nitrate concentration. This behavior was attributed to the changes in the diamond surface chemical and the film grain size.

  15. Excitonic luminescence of SiGe/Si quantum wells δ-doped with boron

    Energy Technology Data Exchange (ETDEWEB)

    Bagaev, V. S.; Nikolaev, S. N.; Onishchenko, E. E.; Pruchkina, A. A. [P.N. Lebedev Physical Institute, Russian Academy of Sciences, Moscow (Russian Federation); Krivobok, V. S., E-mail: krivobok@lebedev.ru [P.N. Lebedev Physical Institute, Russian Academy of Sciences, Moscow (Russian Federation); Moscow Institute of Physics and Technology (State University), Dolgoprudny, Moscow Region (Russian Federation); Novikov, A. V. [Institute for Physics of Microstructures Russian Academy of Sciences, Nizhny Novgorod (Russian Federation); Lobachevsky State University of Nizhni Novgorod, Nizhny Novgorod (Russian Federation)

    2015-05-14

    Low-temperature photoluminescence of undoped and moderately δ-doped Si{sub 1−x}Ge{sub x}/Si (x < 0.1) quantum wells has been studied. The influence of boron δ-layer on the excitonic luminescence and the luminescence caused by a dense electron plasma was demonstrated. The conditions under which the luminescence spectra of quantum wells are dominated by impurity-bound excitons (BE) have been established. Some unusual properties of these BE are explained in terms of type II band-offset in Si{sub 1−x}Ge{sub x}/Si (x < 0.1) quantum wells, which favors a spatial separation of electrons and holes. It is shown that the temperature dependence of an excitonic emission in the quantum wells allows to calculate the BE-related density of states and, thus, can be used for contactless estimation of the impurity concentration in quantum wells.

  16. Neutral and charged boron-doped fullerenes for CO2 adsorption

    Directory of Open Access Journals (Sweden)

    Suchitra W. de Silva

    2014-04-01

    Full Text Available Recently, the capture and storage of CO2 have attracted research interest as a strategy to reduce the global emissions of greenhouse gases. It is crucial to find suitable materials to achieve an efficient CO2 capture. Here we report our study of CO2 adsorption on boron-doped C60 fullerene in the neutral state and in the 1e−-charged state. We use first principle density functional calculations to simulate the CO2 adsorption. The results show that CO2 can form weak interactions with the BC59 cage in its neutral state and the interactions can be enhanced significantly by introducing an extra electron to the system.

  17. Boron doped nanostructure ZnO films deposited by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Highlights: • Nanostructure undoped and boron doped ZnO films were deposited by USP technique. • Influences of doping on the surface and optical properties of the ZnO films were investigated. • XRD spectra of the films exhibited a variation in crystalline quality depending on the B content. - Abstract: ZnO is an II–VI compound semiconductor with a wide direct band gap of 3.3 eV at room temperature. Doped with group III elements (B, Al or Ga), it becomes an attractive candidate to replace tin oxide (SnO2) or indium tin oxide (ITO) as transparent conducting electrodes in solar cell devices and flat panel display due to competitive electrical and optical properties. In this work, ZnO and boron doped ZnO (ZnO:B) films have been deposited onto glass substrates at 350 ± 5 °C by a cost-efficient ultrasonic spray pyrolysis technique. The optical, structural, morphological and electrical properties of nanostructure undoped and ZnO:B films have been investigated. Electrical resistivity of films has been analyzed by four-probe technique. Optical properties and thicknesses of the films have been examined in the wavelength range 1200–1600 nm by using spectroscopic ellipsometry (SE) measurements. The optical constants (refractive index (n) and extinction coefficient (k)) and the thicknesses of the films have been fitted according to Cauchy model. The optical method has been used to determine the band gap value of the films. Transmission spectra have been taken by UV spectrophotometer. It is found that both ZnO and ZnO:B films have high average optical transmission (≥80%). X-ray diffraction (XRD) patterns indicate that the obtained ZnO has a hexagonal wurtzite type structure. The morphological properties of the films were studied by atomic force microscopy (AFM). The surface morphology of the nanostructure films is found to depend on the concentration of B. As a result, ZnO:B films are promising contender for their potential use as transparent window layer and

  18. Boron doped nanostructure ZnO films deposited by ultrasonic spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Karakaya, Seniye, E-mail: seniyek@ogu.edu.tr; Ozbas, Omer

    2015-02-15

    Highlights: • Nanostructure undoped and boron doped ZnO films were deposited by USP technique. • Influences of doping on the surface and optical properties of the ZnO films were investigated. • XRD spectra of the films exhibited a variation in crystalline quality depending on the B content. - Abstract: ZnO is an II–VI compound semiconductor with a wide direct band gap of 3.3 eV at room temperature. Doped with group III elements (B, Al or Ga), it becomes an attractive candidate to replace tin oxide (SnO{sub 2}) or indium tin oxide (ITO) as transparent conducting electrodes in solar cell devices and flat panel display due to competitive electrical and optical properties. In this work, ZnO and boron doped ZnO (ZnO:B) films have been deposited onto glass substrates at 350 ± 5 °C by a cost-efficient ultrasonic spray pyrolysis technique. The optical, structural, morphological and electrical properties of nanostructure undoped and ZnO:B films have been investigated. Electrical resistivity of films has been analyzed by four-probe technique. Optical properties and thicknesses of the films have been examined in the wavelength range 1200–1600 nm by using spectroscopic ellipsometry (SE) measurements. The optical constants (refractive index (n) and extinction coefficient (k)) and the thicknesses of the films have been fitted according to Cauchy model. The optical method has been used to determine the band gap value of the films. Transmission spectra have been taken by UV spectrophotometer. It is found that both ZnO and ZnO:B films have high average optical transmission (≥80%). X-ray diffraction (XRD) patterns indicate that the obtained ZnO has a hexagonal wurtzite type structure. The morphological properties of the films were studied by atomic force microscopy (AFM). The surface morphology of the nanostructure films is found to depend on the concentration of B. As a result, ZnO:B films are promising contender for their potential use as transparent window layer and

  19. Synthesis and Antimicrobial Activity of Boron-doped Titania Nano-materials

    Institute of Scientific and Technical Information of China (English)

    王昱征; 薛向欣; 杨合

    2014-01-01

    Antibacterial activity of boron-doped TiO2 (B/TiO2) nano-materials under visible light irradiation and in the dark was investigated. A simple sol-gel method was used to synthesize TiO2 nano-materials. X-ray diffraction pattern of B/TiO2 nano-materials represents the diffraction peaks relating to the crystal planes of TiO2 (anatase and rutile). X-ray photoelectron spectroscopy result shows that part of boron ions incorporates into TiO2 lattice to form a possible chemical environment like Ti-O-B and the rest exist in the form of B2O3. The study on antibacterial effect of B/TiO2 nano-materials on fungal Candida albicans (ATCC10231), Gram-negative Escherichia coli (ATCC25922) and Gram-positive Staphylococcus aureus (ATCC6538) shows that the antibacterial action is more significant on Candida albicans than on Escherichia coli and Staphylococcus aureus. Under visible light irradiation, the antibacterial activity is superior to that in the dark.

  20. Diffusion-driven precipitate growth and ripening of oxygen precipitates in boron doped silicon by dynamical x-ray diffraction

    OpenAIRE

    Will, Johannes; Gröschel, A.; Bergmann, C.; Spiecker, E.; Magerl, A.

    2014-01-01

    X-ray Pendellösung fringes from three silicon single crystals measured at 900 °C are analyzed with respect to density and size of oxygen precipitates within a diffusion-driven growth model and compared with TEM investigations. It appears that boron doped (p+) material shows a higher precipitate density and a higher strain than moderately (p-) boron crystals. In-situ diffraction reveals a diffusion-driven precipitate growth followed by a second growth regime in both materials. An interpretatio...

  1. Dibenzothiophene adsorption at boron doped carbon nanoribbons studied within density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    López-Albarrán, P. [Facultad de Ingeniería en Tecnología de la Madera, Universidad Michoacana de San Nicolás de Hidalgo, Santiago Tapia 403, CP 58000, Morelia, Michoacán (Mexico); Navarro-Santos, P., E-mail: pnavarrosa@conacyt.mx [Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Santiago Tapia 403, CP 58000, Morelia, Michoacán (Mexico); Garcia-Ramirez, M. A. [Research Centre for Innovation in Aeronautical Engineering, Universidad Autónoma de Nuevo León, Ciudad Universitaria, San Nicolás de los Garza, CP 66451 Nuevo León (Mexico); Ricardo-Chávez, J. L. [Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José 2055, Lomas 4" asección, CP 78216, San Luis Potosí, S. L. P. (Mexico)

    2015-06-21

    The adsorption of dibenzothiophene (DBT) on bare and boron-doped armchair carbon nanoribbons (ACNRs) is being investigated in the framework of the density functional theory by implementing periodic boundary conditions that include corrections from dispersion interactions. The reactivity of the ACNRs is characterized by using the Fukui functions as well as the electrostatic potential as local descriptors. Non-covalent adsorption mechanism is found when using the local Perdew-Becke-Ernzerhof functional, regardless of the DBT orientation and adsorption location. The dispersion interactions addition is a milestone to describe the adsorption process. The charge defects introduced in small number (i.e., by doping with B atoms), within the ACNRs increases the selectivity towards sulfur mainly due to the charge depletion at B sites. The DBT magnitude in the adsorption energy shows non-covalent interactions. As a consequence, the configurations where the DBT is adsorbed on a BC{sub 3} island increase the adsorption energy compared to random B arrangements. The stability of these configurations can be explained satisfactorily in terms of dipole interactions. Nevertheless, from the charge-density difference analysis and the weak Bader charge-distribution interactions cannot be ruled out completely. This is why the electronic properties of the ribbons are analyzed in order to elucidate the key role played by the B and DBT states in the adsorbed configurations.

  2. Modeling the Microstructure Curvature of Boron-Doped Silicon in Bulk Micromachined Accelerometer

    Directory of Open Access Journals (Sweden)

    Xiaoping He

    2013-01-01

    Full Text Available Microstructure curvature, or buckling, is observed in the micromachining of silicon sensors because of the doping of impurities for realizing certain electrical and mechanical processes. This behavior can be a key source of error in inertial sensors. Therefore, identifying the factors that influence the buckling value is important in designing MEMS devices. In this study, the curvature in the proof mass of an accelerometer is modeled as a multilayered solid model. Modeling is performed according to the characteristics of the solid diffusion mechanism in the bulk-dissolved wafer process (BDWP based on the self-stopped etch technique. Moreover, the proposed multilayered solid model is established as an equivalent composite structure formed by a group of thin layers that are glued together. Each layer has a different Young’s modulus value and each undergoes different volume shrinkage strain owing to boron doping in silicon. Observations of five groups of proof mass blocks of accelerometers suggest that the theoretical model is effective in determining the buckling value of a fabricated structure.

  3. Boron doped g-C3N4 with enhanced photocatalytic UO22+ reduction performance

    Science.gov (United States)

    Lu, Changhai; Chen, Rongyue; Wu, Xi; Fan, Meifeng; Liu, Yunhai; Le, Zhanggao; Jiang, Shujuan; Song, Shaoqing

    2016-01-01

    Tuning the band gap and absorption intensity of visible-light by element doping is an attractive strategy to enhance the photocatalytic activity of semiconductor materials. Here we doped boron into g-C3N4 to construct highly efficient photocatalysts (B-g-C3N4) for the photocatalytic reduction of UO22+. Characterization and photocatalysis tests showed the band gap of B-g-C3N4 was narrowed, and the absorption intensity of visible-light was enhanced with increasing the formed N-B-C (BCN) of B-g-C3N4, which is consistent with the trend of the photocatalytic performance of B-g-C3N4. The optimized B-g-C3N4 photocatalyst with BCN content of 1.01 at.% exhibited excellent removal efficiency of UO22+ and good photocatalytic stability. Therefore, these results may lead to a new strategy for exploring the advanced photocatalysts based on the carbon nanomaterials with abundant BCN for the photocatalytic reduction of U(VI) pollutant.

  4. First-principles calculations on the structure and electronic properties of boron doping zigzag single-walled carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Calculations have been made for single-walled zigzag(n,0) carbon nanotubes containing substitutional boron impurity atoms using ab initio density functional theory.It is found that the formation energies of these nanotubes depend on the tube diameter,as do the electronic properties,and show periodic fea-ture that results from their different π bonding structures compared to those of perfect zigzag carbon nanotubes.When more boron atoms are incorporated into a single-walled zigzag carbon nanotube,the substitutional boron atoms tend to come together to form structure of BC3 nanodomains,and B-doped tubes have striking acceptor states above the top of the valence bands.For the structure of BC3,there are two kinds of configurations with different electronic structures.

  5. Analysis of laser doping of silicon using different boron dopant sources

    Energy Technology Data Exchange (ETDEWEB)

    Prathap, P., E-mail: pathiprathap@gmail.com [InESS, CNRS-UdS, Strasbourg Cedex-2 (France); National Physical Laboratory, KS Krishnan Road, New Delhi 110012 (India); Bartringer, J.; Slaoui, A. [InESS, CNRS-UdS, Strasbourg Cedex-2 (France)

    2014-05-01

    Implementation of selective emitter that decouples the requirements for front doping and metallization leads to improve the efficiency of crystalline silicon solar cells. Formation of such an efficient selective emitter using a laser beam with a suitable wavelength is an attractive method. The present work focuses on the analysis of laser doping of boron using different finite sources such as borosilicate glass (BSG) deposited by PECVD, spin-on solution and BCl{sub 3} gas source. KrF excimer laser (248 nm) was used for the selective doping. The surface dopant concentration and depth, as measured using SIMS, were controlled by variation of the laser fluence, pulse number and dopant source thickness. Depending on the type of BSG source, sheet resistance close to 20 Ω/sq was achieved at the laser fluences in the range, 2.5–5 J/cm{sup 2}. The PECVD-BSG layers with a relatively higher thickness resulted in a lower sheet resistance of 20 Ω/sq with a junction of depth of ∼1 μm at a moderate laser fluence of 2.5 J/cm{sup 2}. In the case of BSG deposited by spin-on source, a deeper junction of depth of ∼2.7 μm with a plateau profile of 1 μm was formed at a laser fluence of 3.1 J/cm{sup 2} that resulted in a lower sheet resistance of ∼31 Ω/sq. Redistribution of the dopant with pulse repetition was observed for the BSG deposited by BCl{sub 3} gas source. Pulse repetition at relatively lower laser fluences (>threshold energy) resulted in the best electrical results in combination with a limited laser induced damage in the silicon crystal. Also, multiple laser annealing resulted in redistribution of the dopant profiles in terms of enhanced junction depth.

  6. Investigation of catalytic activity towards oxygen reduction reaction of Pt dispersed on boron doped graphene in acid medium.

    Science.gov (United States)

    Pullamsetty, Ashok; Sundara, Ramaprabhu

    2016-10-01

    Boron doped graphene was prepared by a facile method and platinum (Pt) decoration over boron doped graphene was done in various chemical reduction methods such as sodium borohydride (NaBH4), polyol and modified polyol. X-ray diffraction analysis indicates that the synthesized catalyst particles are present in a nanocrystalline structure and transmission and scanning electron microscopy were employed to investigate the morphology and particle distribution. The electrochemical properties were investigated with the help of the rotating disk electrode (RDE) technique and cyclic voltammetry. The results show that the oxygen reduction reaction (ORR) takes place by a four-electron process. The kinetics of the ORR was evaluated using K-L and Tafel plots. The electrocatalyst obtained in modified polyol reduction method has shown the better catalytic activity compared to other two electrocatalysts. PMID:27393888

  7. Facile Synthesis of Boron-Doped rGO as Cathode Material for High Energy Li-O2 Batteries.

    Science.gov (United States)

    Wu, Feng; Xing, Yi; Li, Li; Qian, Ji; Qu, Wenjie; Wen, Jianguo; Miller, Dean; Ye, Yusheng; Chen, Renjie; Amine, Khalil; Lu, Jun

    2016-09-14

    To improve the electrochemical performance of the high energy Li-O2 batteries, it is important to design and construct a suitable and effective oxygen-breathing cathode. Herein, a three-dimensional (3D) porous boron-doped reduction graphite oxide (B-rGO) material with a hierarchical structure has been prepared by a facile freeze-drying method. In this design, boric acid as the boron source helps to form the 3D porous structure, owing to its cross-linking and pore-forming function. This architecture facilitates the rapid oxygen diffusion and electrolyte penetration in the electrode. Meanwhile, the boron-oxygen functional groups linking to the carbon surface or edge serve as additional reaction sites to activate the ORR process. It is vital that boron atoms have been doped into the carbon lattices to greatly activate the electrons in the carbon π system, which is beneficial for fast charge under large current densities. Density functional theory calculation demonstrates that B-rGO exhibits much stronger interactions with Li5O6 clusters, so that B-rGO more effectively activates Li-O bonds to decompose Li2O2 during charge than rGO does. With B-rGO as a catalytic substrate, the Li-O2 battery achieves a high discharge capacity and excellent rate capability. Moreover, catalysts could be added into the B-rGO substrate to further lower the overpotential and enhance the cycling performance in future. PMID:27549204

  8. Boron-doped silicon film as a recombination layer in the tunnel junction of a tandem solar cell

    Institute of Scientific and Technical Information of China (English)

    Shi Mingji; Wang Zhanguo; Liu Shiyong; Peng Wenbo; Xiao Haibo; Zhang Changsha; Zeng Xiangbo

    2009-01-01

    Boron-doped hydrogenated silicon films with different gaseous doping ratios (B2H6/SiH4) were deposited in a plasma-enhanced chemical vapor deposition (PECVD) system. The microstructure of the films was investigated by atomic force microscopy (AFM) and Raman scattering spectroscopy. The electrical properties of the films were characterized by their room temperature electrical conductivity (σ) and the activation energy (Ea). The results show that with an increasing gaseous doping ratio, the silicon films transfer from a microcrystalline to an amorphous phase, and corresponding changes in the electrical properties were observed. The thin boron-doped silicon layers were fabricated as recombination layers in tunnel junctions. The measurements of the Ⅰ-Ⅴ characteristics and the transparency spectra of the junctions indicate that the best gaseous doping ratio of the recombination layer is 0.04, and the film deposited under that condition is amorphous silicon with a small amount of crystallites embedded in it. The junction with such a recombination layer has a small resistance, a nearly ohmic contact, and a negligible optical absorption.

  9. Preparation and visible-light-driven photoelectrocatalytic properties of boron-doped TiO2 nanotubes

    International Nuclear Information System (INIS)

    In the present study, chemical vapour deposition (CVD) was applied to dope boron into TiO2 nanotubes anodized Ti in C2H2O4.2H2O + NH4F electrolyte with the goal of improving the photocatalytic (PC) activity under visible light. The undoped TiO2 nanotubes had a highly self-organized structure. However, after doping through CVD, TiO2 nanotubes suffered from an observable disintegration of morphological integrity. X-ray diffraction (XRD) results confirmed that annealing temperature had an influence on the phase structure and boron impurities could retard anatase-rutile phase transition. Diffuse reflectance absorption spectra (DRS) analysis indicated that B-doped samples displayed stronger absorption in both UV and visible range. B-doped TiO2 nanotubes electrode annealed at 700 deg. C through CVD showed higher photoelectrocatalytic (PEC) efficiency in methyl orange (MO) degradation than that annealed at 400 deg. C and 550 deg. C. MO degradation was substantially enhanced with the increasing applied bias potential. Moreover, there was a synergetic effect between the electrochemical and photocatalytic processes, and the synergetic factor R reached 1.45. B-doped TiO2 nanotubes electrode showed good stability after 10 times by repeating photoelectrocatalysis of MO

  10. Electron-phonon interaction in boron-doped silicon nanocrystals: effect of Fano interference on combined light scattering

    International Nuclear Information System (INIS)

    The arrays of the silicon nanocrystals in the boron-doped amorphous silicon films are studied by the method of the light combined scattering spectroscopy. The nanocrystals were formed in the initial amorphous films under the pulse effect of the excimer laser. The effects of the electron-phonon interaction were experimentally identified in the silicon nanocrystal/amorphous matrix heterostructure. These effects may be described within the frames of the known Fano interference model

  11. Fabrication of boron-doped carbon fibers by the decomposition of B4C and its excellent rate performance as an anode material for lithium-ion batteries

    Science.gov (United States)

    Wang, Huiqi; Ma, Canliang; Yang, Xueteng; Han, Tao; Tao, Zechao; Song, Yan; Liu, Zhanjun; Guo, Quangui; Liu, Lang

    2015-03-01

    A facile route, for the first time, was developed to fabricate boron-doped carbon fibers (BDCFs). Boron was doped into mesosphere pitch-based carbon fibers (CFs) by exposing the CFs in a vapor of boron by the decomposition of boron carbide. The microstructure of BDCFs was characterized by SEM, TEM, XRD and Raman spectroscopy. When used as anode materials for the lithium-ion batteries, BDCFs electrode exhibits an improved performance. Concretely, the specific capacity of BDCFs still had a value of over 400 mAh g-1 after 100 cycles. Moreover, BDCFs exhibits better rate capability and less hysteresis in comparison to the pristine CFs. Such enhanced lithium storage capability can be attributed to the improvement of graphitization properties and the high amount of defects induced by boron.

  12. Highly transparent and conducting boron doped zinc oxide films for window of Dye Sensitized Solar Cell applications

    International Nuclear Information System (INIS)

    Highlights: ► Synthesis of Boron doped ZnO (ZnO:B) films. ► Minimum of resistivity is observed to be 7.9 × 10−4 Ω cm. ► Maximum transmittance ∼91% for 450 °C annealed films. ► Applicable for window materials in Dye Sensitized Solar Cell. - Abstract: Highly transparent and conducting boron doped zinc oxide (ZnO:B) films grown by sol–gel method are reported. The annealing temperature is varied from 350 to 550 °C and doping concentration of boron is kept fixed for 0.6 at.% for all the films. At low temperature the stress in the films is compressive, which becomes tensile for the films annealed at higher temperature. A minimum resistivity of 7.9 × 10−4 Ω cm and maximum transmittance of ∼91% are observed for the film annealed at 450 °C. This could be attributed to minimum stress of films, which is further evident by the evolution of A1 and defect related Raman modes without any shifting in its position. Such kind of highly transparent and conducting ZnO:B thin film could be used as window material in Dye Sensitized Solar Cell (DSSC).

  13. Differences in the tribological mechanisms when using non-doped, metal-doped (Ti, WC), and non-metal-doped (Si) diamond-like carbon against steel under boundary lubrication, with and without oil additives

    OpenAIRE

    Kalin, Mitjan; Vižintin, Jože

    2015-01-01

    In this paper, we report on the tribological performance and mechanisms of the boundary-lubricated contacts of steel against diamond-like carbon (DLC) coatings, i.e., steel/DLC, using the same materials, oils, additives and conditions as we have previously reported for DLC/DLC contacts. We present and compare the behaviour of two non-doped, two metal-doped (Ti, WC) and one non-metal-doped (Si) DLC coatings in contact with steel surfaces in reciprocating sliding, lubricated with a paraffinic m...

  14. Characteristics of Nitrogen Doped Diamond-Like Carbon Films Prepared by Unbalanced Magnetron Sputtering for Electronic Devices.

    Science.gov (United States)

    Lee, Jaehyeong; Choi, Byung Hui; Yun, Jung-Hyun; Park, Yong Seob

    2016-05-01

    Synthetic diamond-like carbon (DLC) is a carbon-based material used mainly in cutting tool coatings and as an abrasive material. The market for DLC has expanded into electronics, optics, and acoustics because of its distinct electrical and optical properties. In this work, n-doped DLC (N:DLC) films were deposited on p-type silicon substrates using an unbalanced magnetron sputtering (UBMS) method. We investigated the effect of the working pressure on the microstructure and electrical properties of n-doped DLC films. The structural properties of N:DLC films were investigated by Raman spectroscopy and SEM-EDX, and the electrical properties of films were investigated by observing the changes in the resistivity and current-voltage (I-V) properties. The N:DLC films prepared by UBMS in this study demonstrated good conducting and physical properties with n-doping. PMID:27483841

  15. Characteristics of Nitrogen Doped Diamond-Like Carbon Films Prepared by Unbalanced Magnetron Sputtering for Electronic Devices.

    Science.gov (United States)

    Lee, Jaehyeong; Choi, Byung Hui; Yun, Jung-Hyun; Park, Yong Seob

    2016-05-01

    Synthetic diamond-like carbon (DLC) is a carbon-based material used mainly in cutting tool coatings and as an abrasive material. The market for DLC has expanded into electronics, optics, and acoustics because of its distinct electrical and optical properties. In this work, n-doped DLC (N:DLC) films were deposited on p-type silicon substrates using an unbalanced magnetron sputtering (UBMS) method. We investigated the effect of the working pressure on the microstructure and electrical properties of n-doped DLC films. The structural properties of N:DLC films were investigated by Raman spectroscopy and SEM-EDX, and the electrical properties of films were investigated by observing the changes in the resistivity and current-voltage (I-V) properties. The N:DLC films prepared by UBMS in this study demonstrated good conducting and physical properties with n-doping.

  16. Optical and electronic properties of SO2 molecule adsorbed on Si-doped (8, 0) boron nitride nanotube

    Science.gov (United States)

    Guo, Shuang-Shuang; Wei, Xiu-Mei; Zhang, Jian-Min; Zhu, Gang-Qiang; Guo, Wan-Jin

    2016-09-01

    The study of the optical properties of pristine BNNT, Si-doped BNNTs and SO2 molecule adsorption on Si-doped BNNTs is that, to our knowledge, few relevant research have ever been found. In this paper, the adsorption behaviors of Sulfur dioxide (SO2) molecule on Si-doped Boron nitride nanotubes (BNNTs) are investigated applying the first-principles calculations. The main contribution of this paper is that the foremost investigation for the optical properties of the pristine BNNT, Si-doped BNNTs and SO2 adsorption on Si-doped BNNTs. Additionally, the electronic properties and the structural properties are also presented. In our calculations of optical properties, the dielectric constant, the refractive index and the absorption coefficient are obtained. Comparing the pristine BNNT, our results indicate that, the blue-shifts (in the main peaks of the dielectric constant of SiB -BNNT and SO2-SiB -BNNT), and the red-shifts (in the main peaks of the refractive index of SiN -BNNT and SO2-SiN -BNNT) are appeared. Under these conditions, Si-doped BNNT and Si-doped BNNT with SO2 adsorption, the gaps are reduced both for the speculated optical band gaps and the electronic structure band gaps.

  17. Insertion of nanocrystalline diamond film and the addition of hydrogen gas during deposition for adhesion improvement of cubic boron nitride thin film deposited by unbalanced magnetron sputtering method

    International Nuclear Information System (INIS)

    Cubic boron nitride (c-BN) thick film growth was attempted by the addition of hydrogen for residual stress reduction and by using a nanocrystalline diamond (NCD) buffer layer for stabilizing the turbostratic boron nitride interfacial layer. The c-BN films were deposited by the unbalanced magnetron sputtering method. Thin (100 μm) Si strips (3 × 40 mm2) were used as substrates. A boron nitride target was used, which was connected to a radio frequency power supply at 400 W. High frequency power connected to a substrate holder was used for self-biasing of − 40 V. The deposition pressure was 0.27 Pa with a flow of Ar (18 sccm)–N2 (2 sccm) mixed gas. Hydrogen gas of 2 sccm was added to the Ar–N2 mixed gas. The effect of the addition time of the hydrogen to the Ar–N2 gas during deposition was investigated and found to be critical to the occurrence of the delamination of the c-BN film on the NCD buffer layer. As the addition of the hydrogen was delayed, the delamination started later. C-BN film of 3 μm thickness adherent to the substrate was obtained. - Highlights: • A nanocrystalline diamond (NCD) buffer layer was applied to enhance the adhesion. • Hydrogen in the reaction gas caused delamination of the film at c-BN/NCD interface. • A delayed hydrogen addition was effective in inhibiting such delamination. • About 3 μm thick c-BN film could be grown

  18. Stabilizing shallow color centers in diamond created by nitrogen delta-doping using SF{sub 6} plasma treatment

    Energy Technology Data Exchange (ETDEWEB)

    Osterkamp, Christian; Lang, Johannes; Scharpf, Jochen; Müller, Christoph; McGuinness, Liam Paul; Naydenov, Boris, E-mail: boris.naydenov@uni-ulm.de; Jelezko, Fedor [Institut für Quantenoptik, Universität Ulm, Albert Einstein Allee 11, Ulm 89081 (Germany); Diemant, Thomas; Behm, R. Jürgen [Institut für Oberflächenchemie und Katalyse, Universität Ulm, Albert-Einstein-Allee 47, Ulm 89081 (Germany)

    2015-03-16

    Here we report the fabrication of stable, shallow (<5 nm) nitrogen-vacancy (NV) centers in diamond by nitrogen delta doping at the last stage of the chemical vapor deposition growth process. The NVs are stabilized after treating the diamond in SF{sub 6} plasma, otherwise the color centers are not observed, suggesting a strong influence from the surface. X-ray photoelectron spectroscopy measurements show the presence of only fluorine atoms on the surface, in contrast to previous studies, indicating very good surface coverage. We managed to detect hydrogen nuclear magnetic resonance signal from protons in the immersion oil, revealing a depth of the NVs of about 5 nm.

  19. Neutron radiations effects on tungsten and vanadium oxides doped with boron

    International Nuclear Information System (INIS)

    We present the preliminary results of the Monte Carlo simulation of the damage produced in thin tungsten and vanadium oxide doped with boron by the α particles and lithium ions (Li+), generated as a result of the nuclear reaction 10B(n, α)7Li. The algorithm used in the simulation is based on the technique of approach of binary collisions, implemented in the package TRIM. In the numerical experiment are generated randomly α particles and ions 7Li with energy 1473 ± 50keV and 840 ± 50keV respectively, that soon interacts with the components of the material. The important parameter as the nuclear and electronic stopping power of both particles is calculated. The average walk of α particles in V2O5 is approximately 3,78 μm, whereas in amorphous WO3 is 4,19 μm. We observed that there is greater damage produced by particles of 7Li, in comparison that the produced by α particles for both materials. (author)

  20. Effect of substrate temperature on the growth and properties of boron-doped microcrystalline silicon films

    Institute of Scientific and Technical Information of China (English)

    Lei Qing-Song; Wu Zhi-Meng; Geng Xin-Hua; Zhao Ying; Sun Jian; Xi Jian-Ping

    2006-01-01

    Highly conductive boron-doped hydrogenated microcrystalline silicon (μc-Si:H) films are prepared by very high frequency plasma enhanced chemical vapour deposition (VHF PECVD) at the substrate temperatures (Ts) ranging from 90℃ to 270℃. The effects of Ts on the growth and properties of the films are investigated. Results indicate that the growth rate, the electrical (dark conductivity, carrier concentration and Hall mobility) and structural (crystallinity and grain size) properties are all strongly dependent on Ts. As Ts increases, it is observed that 1) the growth rate initially increases and then arrives at a maximum value of 13.3 nm/min at Ts=210℃, 2) the crystalline volume fraction (Xc) and the grain size increase initially, then reach their maximum values at Ts = 140℃, and finally decrease, 3) the dark conductivity (σd),carrier concentration and Hall mobility have a similar dependence on Tg and arrive at their maximum values at Ts=190℃. In addition, it is also observed that at a lower substrate temperature Ts, a higher dopant concentration is required in order to obtain a maximum σd.

  1. High field magnetic behavior in Boron doped Fe2VAl Heusler alloys

    Science.gov (United States)

    Venkatesh, Ch.; Vasundhara, M.; Srinivas, V.; Rao, V. V.

    2016-11-01

    We have investigated the magnetic behavior of Fe2VAl1-xBx (x=0, 0.03, 0.06 and 0.1) alloys under high temperature and high magnetic field conditions separately. Although, the low temperature DC magnetization data for the alloys above x>0 show clear magnetic transitions, the zero field cooled (ZFC) and field cooled (FC) curves indicate the presence of spin cluster like features. Further, critical exponent (γ) deduced from the initial susceptibility above the Tc, does not agree with standard models derived for 3 dimensional long range magnetic systems. The deviation in γ values are consistent with the short range magnetic nature of these alloys. We further extend the analysis of magnetic behavior by carrying the magnetization measurements at high temperatures and high magnetic fields distinctly. We mainly emphasize the following observations; (i) The magnetic hysteresis loops show sharp upturns at lower fields even at 900 K for all the alloys. (ii) High temperature inverse susceptibility do not overlap until T=900 K, indicating the persistent short range magnetic correlations even at high temperatures. (iii) The Arrott's plot of magnetization data shows spontaneous moment (MS) for the x=0 alloy at higher magnetic fields which is absent at lower fields (<50 kOe), while the Boron doped samples show feeble MS at lower fields. The origin of this short range correlation is due to presence of dilute magnetic heterogeneous phases which are not detected from the X-ray diffraction method.

  2. Adsorption properties of boroxol ring doped zigzag boron nitride nanotube toward NO molecule using DFT

    Science.gov (United States)

    Zahedi, Ehsan; Babaie, Mahsa; Bahmanpour, Hooman

    2016-05-01

    In previous researches it is demonstrated that reactivity and sensitivity of boron nitride nanotubes (BNNTs) toward gas molecules can be modified by impurity. In this work, oxygen defect for three nitrogen sites was used to study the adsorption of NO molecule through the surface of boroxol ring of oxygen doped BNNT (7,0) with different adsorption patterns, including side-on and end-on. All calculations are performed using the DFT-B3LYP/6-31G∗ level of theory, and their electronic energies are corrected by gCP and D3 correction terms. High binding energies indicate that NO molecule undergoes chemical adsorption with large charge transfer from the tube which can significantly change electronic properties of the tube. Density of state (DOS) and partial DOS (PDOS) analyses revealed that adsorption of NO molecule on the boroxol ring position is covalent in nature with significant effect on the electronic properties of tube. The Laplacian of electron density, Lagrangian kinetic energy density, Hamiltonian kinetic energy density and potential energy density at bond critical points between the tube and NO indicate that the interaction between the tube and NO molecule is covalent in nature. Topological analysis of the electron localization function shows that electrons in the new formed bonds are approximately localized, meaning that the nature of adsorption process is chemical covalent. The studied nanotube is a suitable candidate to filter and eliminate NO gas molecule.

  3. Structural modification of boron-doped ZnO layers caused by hydrogen outgassing

    Energy Technology Data Exchange (ETDEWEB)

    Lovics, R.; Csik, A., E-mail: csik@atomki.hu; Takáts, V.; Hakl, J.; Vad, K.

    2015-07-01

    Results of annealing experiments of boron-doped zinc oxide (ZnO:B) layers prepared by low pressure chemical vapor deposition method on polished Si, soda-lime glass for windows, and AF45 Schott alkali free thin glass substrates are presented. It is shown that short annealing of samples at 150 °C and 300 °C in air causes serious surface degradation of samples prepared on Si and soda-lime glass substrate. The characteristic feature of degradation is the creation of bubbles and craters on the sample surface which fully destroy the continuity of zinc oxide layers. The results of depth distribution mapping of elements indicate that the formation of bubbles is linked to increase in hydrogen concentration in the layer. The surface degradation was not noticed on samples deposited on AF45 Schott alkali free thin glass which has a SiO{sub 2} diffusion barrier layer on the surface, only much fewer and smaller bubbles were visible. The results indicate the important role of hydrogen outgassing from the substrate induced by a thermal shock.

  4. Electrochemical Characteristics and Applications of Boron-Doped Polycrystalline Diamond Film Electrodes

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    ns of Boron-Doped Polycrystalline Diamond Film ElectrodesTX1IntroductionInelectrochemicalstudies,electrodesmadeofcom-monlyused...

  5. Studies on the oxygen precipitation in highly boron doped silicon; Untersuchungen zur Sauerstoffausscheidung in hoch bordotiertem Silicium

    Energy Technology Data Exchange (ETDEWEB)

    Zschorsch, Markus

    2007-12-14

    The aim of this thesis was the getting of new knowledge on the elucidation of the oxygen precipitation in highly doped silicon. In the study of the early phases of the oxygen precipitation boron-oxygen complexes and their kinetics could be indirectly detected. These arise already during the cooling of the crystal and can be destroyed by subsequent temperature processes. The formation of the here as BO assumed species during the cooling after the silicon crystal fabrication could be numerically reproduced. Furthermore the study of early precipitation phases by means of neutron small angle scattering a maximum of the oxygen precipitation at {rho}=9 m{omega}cm. It could be shown that the decreasing of this at increasing boron concentration can be most probably reduced to boron precipitations. Furthermore it could be shown that after a tempering time of 24 hours at 700 C in silicon with {rho}=9 m{omega}cm platelet-shaped precipitates form. By the study of the precipitate growth could be shown that also in this phase the oxygen precipitation in silicon is strongest with a specific resistance of {rho}=9 m{omega}cm. By means of FTIR spectroscopy a new absorption band at a wave number of 1038 cm{sup -1} was found, which could be assigned to a boron species. By different experiments it is considered as probable that at this species it deals with BI respectively B{sub 2}I complexes.

  6. Fabrication and Application of High Quality Diamond-coated Tools

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Diamond-coated tools were fabricated using Co-cemented carbide inserts as substrates by the electronically aided hot filament chemical vapor deposition (EACVD). An amount of additive in an acid solution was used to promote the Co etching of the substrate surface. The surface of the WC-Co substrate was decarburized by microwave plasma with Ar-H 2 gas. Effect of the new substrate pretreatment on the adhesion of diamond films was investigated. A boron-doped solution was brushed on the tool surface to diffuse ...

  7. Diffusion-driven precipitate growth and ripening of oxygen precipitates in boron doped silicon by dynamical x-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Will, J., E-mail: will@krist.uni-erlangen.de; Gröschel, A.; Bergmann, C.; Magerl, A. [Crystallography and Structural Physics, University of Erlangen-Nürnberg, Staudtstr. 3, 91058 Erlangen (Germany); Spiecker, E. [Center for Nanoanalysis and Electron Microscopy, University of Erlangen-Nürnberg, Cauerstr. 6, 91058 Erlangen (Germany)

    2014-03-28

    X-ray Pendellösung fringes from three silicon single crystals measured at 900 °C are analyzed with respect to density and size of oxygen precipitates within a diffusion-driven growth model and compared with TEM investigations. It appears that boron doped (p+) material shows a higher precipitate density and a higher strain than moderately (p-) boron crystals. In-situ diffraction reveals a diffusion-driven precipitate growth followed by a second growth regime in both materials. An interpretation of the second growth regime in terms of Ostwald ripening yields surface energy values (around 70 erg/cm{sup 2}) similar to published data. Further, an increased nucleation rate by a factor of ∼13 is found in the p+ sample as compared to a p- sample at a nucleation temperature of 450 °C.

  8. Research on the direct doping effect of silicon on cubic boron nitride ceramics by UV-VIS diffuse reflectance

    International Nuclear Information System (INIS)

    Cubic boron nitride (cBN) micro-powders mixed with 1 wt% silicon were sintered at 1450 deg. C under a pressure of 5.0 GPa. The grain boundaries and silicon distribution in Si-cBN ceramics were studied by scanning electronic microscope (SEM) and energy-dispersive spectrometer (EDS). Optical properties of the ceramics were investigated by UV-VIS diffuse reflectance and photoluminescence spectra at room temperature. Some important parameters of studied ceramics such as absorption coefficient and defect levels were identified from reflection spectra by intercept method. The experimental results indicated the direct n-doped effect of silicon on cubic boron nitride ceramics. With a direct forbidden transition characteristic, the donor energy level of Si in forbidden zone of cBN ceramics was found to be 2.82 eV. The phonon energy related to the direct forbidden transition was 0.235 eV.

  9. Study on excimer laser irradiation for controlled dehydrogenation and crystallization of boron doped hydrogenated amorphous/nanocrystalline silicon multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Gontad, F., E-mail: fran_gontad@yahoo.es [Applied Physics Department, University of Vigo, E.I. Industrial, Campus de As Lagoas, Marcosende, E-36310, Vigo (Spain); Conde, J.C. [Applied Physics Department, University of Vigo, E.I. Industrial, Campus de As Lagoas, Marcosende, E-36310, Vigo (Spain); Filonovich, S.; Cerqueira, M.F.; Alpuim, P. [Department of Physics, University of Minho, Campus de Azurém, 4800-058 Guimarães (Portugal); Chiussi, S. [Applied Physics Department, University of Vigo, E.I. Industrial, Campus de As Lagoas, Marcosende, E-36310, Vigo (Spain)

    2013-06-01

    We report on the excimer laser annealing (ELA) induced temperature gradients, allowing controlled crystallization and dehydrogenation of boron-doped a-Si:H/nc-Si:H multilayers. Depth of the dehydrogenation and crystallization process has been studied numerically and experimentally, showing that temperatures below the monohydride decomposition can be used and that significant changes of the doping profile can be avoided. Calculation of temperature profiles has been achieved through numerical modeling of the heat conduction differential equation. Increase in the amount of nano-crystals, but not in their size, has been demonstrated by Raman spectroscopy. Effective dehydrogenation and shape of the boron profile have been studied by time of flight secondary ion mass spectroscopy. The relatively low temperature threshold for dehydrogenation, below the monohydride decomposition temperature, has been attributed to both, the large hydrogen content of the original films and the partial crystallization during the ELA process. The results of this study show that UV-laser irradiation is an effective tool to improve crystallinity and dopant activation in p{sup +}-nc-Si:H films without damaging the substrate. - Highlights: • An efficient dehydrogenation is possible through excimer laser annealing. • 140 mJ/cm{sup 2} is enough for dehydrogenation without significant changes in doping profile. • Fluences up to 300 mJ/cm{sup 2} promote partial crystallization of the amorphous structures.

  10. Effect of reaction conditions on methyl red degradation mediated by boron and nitrogen doped TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Galenda, A., E-mail: galenda@ieni.cnr.it [CNR-IENI, Istituto per l’Energetica e le Interfasi, Corso Stati Uniti, 4 35127 Padova (Italy); Crociani, L.; Habra, N. El; Favaro, M. [CNR-IENI, Istituto per l’Energetica e le Interfasi, Corso Stati Uniti, 4 35127 Padova (Italy); Natile, M.M. [CNR-IENI, Istituto per l’Energetica e le Interfasi, Dipartimento di Scienze Chimiche, Università di Padova, via F. Marzolo, 1 35131 Padova (Italy); Rossetto, G. [CNR-IENI, Istituto per l’Energetica e le Interfasi, Corso Stati Uniti, 4 35127 Padova (Italy)

    2014-09-30

    Highlights: • Boron and/or nitrogen-doped TiO{sub 2} for photocatalytic wastewater treatment. • Methyl red degradation/mineralisation as a function of pH, acids and dopants. • Adsorption time influence on photocatalytic process. • Recovery of worn-out catalyst. - Abstract: Nowadays the employment of renewable and sustainable energy sources, and solar light as main option, becomes an urgent need. Photocatalytic processes received great attention in wastewater treatment due to their cheapness, environmental compatibility and optimal performances. Despite the general low selectivity of the photocatalysts, an accurate optimisation of the operational parameters needs to be carried out in order to maximise the process yield. Because of this reason, the present contribution aims to deepen either the knowledge in boron and/or nitrogen doped TiO{sub 2}-based systems and their employment in methyl red removal from aqueous solutions. The samples were obtained by coprecipitation and characterised by XRD, SEM, BET specific surface area, UV–vis and XPS techniques. The catalytic activity was for the first time carefully evaluated with respect to methyl red photodegradation in different conditions as a function of working pH, counter-ions and pre-adsorption time. An ad-hoc study was performed on the importance of the pre-adsorption of the dye, suggesting that an extended adsorption is useless for the catalyst photoactivity, while a partial coverage is preferable. The photocatalytic tests demonstrate the positive influence of boron doping in photo-activated reactions and the great importance of the operational parameters with respect to the simple methyl red bleaching rather than the overall pollutant mineralisation. It is proved, indeed, that different working pH, acidifying means and substrate pre-adsorption time can enhance or limit the catalyst performances with respect to the complete pollutant degradation rather than its partial breakage.

  11. Magnetism of single-walled silicon carbide nanotubes doped by boron, nitrogen and oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Maghnaoui, Ahmed [Laboratoire de Physique, Universite du 08 mai 45, BP 401, 24000 Guelma (Algeria); Boufelfel, Ahmed, E-mail: ahboufelfel@gmail.com [Laboratoire de Physique, Universite du 08 mai 45, BP 401, 24000 Guelma (Algeria)

    2012-09-15

    We calculated, using spin polarized density functional theory, the electronic properties of zigzag (10,0) and armchair (6,6) semiconductor silicon carbide nanotubes (SiCNTs) doped once at the time with boron, nitrogen, and oxygen. We have looked at the two possible scenarios where the guest atom X (B, N, O), replaces the silicon X{sub Si}, or the carbon atom X{sub C}, in the unit cell. We found that in the case of one atom B - SiCNT replacing a carbon atom position annotated by B{sub C} exhibits a magnetic moment of 1 {mu}{sub B}/cell in both zigzag and armchair nanotubes. Also, B replacing Si, (B{sub Si}), induce a magnetic moment of 0.46 {mu}{sub B}/cell in the zigzag (10,0) but no magnetic moment in armchair (6,6). For N substitution; (N{sub C}) and (N{sub Si}) each case induce a magnetic moment of 1 {mu}{sub B}/cell in armchair (6,6), while N{sub Si} give rise to 0.75 {mu}{sub B}/cell in zigzag (10,0) and no magnetic moment for N{sub C}. In contrast the case of O{sub C} and O{sub Si} did not produce any net magnetic moment in both zigzag and armchair geometries. - Highlights: Black-Right-Pointing-Pointer Calculation scheme the one implemented in the SIESTA. Black-Right-Pointing-Pointer Materials studied SiCNT, B - SiCNT, N - SiCNT and O - SiCNT. Black-Right-Pointing-Pointer Magnetism in single wall SiCNTs when one atom of C or Si is replaced by B or N zigzag (10,0) and armchair (6,6).

  12. Synthesis and characterization of carbon or/and boron-doped CdS nanoparticles and investigation of optical and photoluminescence properties

    International Nuclear Information System (INIS)

    Un-doped and carbon or/and boron doped Cadmium sulfide nanoparticles were prepared via chemical co-precipitation procedure by Polyvinyl pyrrolidone (PVP) as a stabilizer. The optical and structural properties were investigated using several techniques. The morphology of CdS nanophotocatalyst was characterized using X-ray diffraction (XRD) and scanning electron microscopy. The optical properties of both un-doped and doped samples were carried out by photoluminescence (PL) spectroscopy and UV–vis Diffuse reflectance spectra (DRS). An optimum doping level of the atoms dopant for enhanced PL properties are found through optical study. Degradation of Amoxicillin under UV light elucidation was applied to appraise the photocatalytic efficiency. The results show that the carbon and boron doping CdS nanoparticles has high potential in green chemistry. - Highlights: • Un-doped, C or/and B-doped CdS nanoparticles were successfully synthesized. • The Blue shift was observed in UV–vis absorption spectra for the doped nanoparticles. • Doping of CdS with C and B enhances the fluorescence

  13. Synthesis and characterization of carbon or/and boron-doped CdS nanoparticles and investigation of optical and photoluminescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Fakhri, Ali, E-mail: ali.fakhri88@yahoo.com [Department of Chemistry, Shahr-e-Qods Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Young Researchers and Elite Club, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Khakpour, Reza [Department of Physics, Tehran North Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)

    2015-04-15

    Un-doped and carbon or/and boron doped Cadmium sulfide nanoparticles were prepared via chemical co-precipitation procedure by Polyvinyl pyrrolidone (PVP) as a stabilizer. The optical and structural properties were investigated using several techniques. The morphology of CdS nanophotocatalyst was characterized using X-ray diffraction (XRD) and scanning electron microscopy. The optical properties of both un-doped and doped samples were carried out by photoluminescence (PL) spectroscopy and UV–vis Diffuse reflectance spectra (DRS). An optimum doping level of the atoms dopant for enhanced PL properties are found through optical study. Degradation of Amoxicillin under UV light elucidation was applied to appraise the photocatalytic efficiency. The results show that the carbon and boron doping CdS nanoparticles has high potential in green chemistry. - Highlights: • Un-doped, C or/and B-doped CdS nanoparticles were successfully synthesized. • The Blue shift was observed in UV–vis absorption spectra for the doped nanoparticles. • Doping of CdS with C and B enhances the fluorescence.

  14. Explaining Morphological and Electrical Features of Boron-doped Zinc Oxide to Tailor New Electrodes for Photovoltaics

    OpenAIRE

    Fanni, Lorenzo

    2016-01-01

    TCOs are a class of metal oxides that combine transparency to visible light with electrical conductivity. Each TCO is characterized by the trade-off of these two properties which can be tuned for a particular application. This thesis is dedicated to the investigation of one TCO material: boron doped zinc oxide (ZnO:B) deposited by low-pressure chemical vapor deposition (LP-MOCVD). Its main distinction is low absorptance which makes ZnO films deposited by LP-MOCVD ideal as transparent electro...

  15. Gas Permeation, Mechanical Behavior and Cytocompatibility of Ultrathin Pure and Doped Diamond-Like Carbon and Silicon Oxide Films

    Directory of Open Access Journals (Sweden)

    Juergen M. Lackner

    2013-12-01

    Full Text Available Protective ultra-thin barrier films gather increasing economic interest for controlling permeation and diffusion from the biological surrounding in implanted sensor and electronic devices in future medicine. Thus, the aim of this work was a benchmarking of the mechanical oxygen permeation barrier, cytocompatibility, and microbiological properties of inorganic ~25 nm thin films, deposited by vacuum deposition techniques on 50 µm thin polyetheretherketone (PEEK foils. Plasma-activated chemical vapor deposition (direct deposition from an ion source was applied to deposit pure and nitrogen doped diamond-like carbon films, while physical vapor deposition (magnetron sputtering in pulsed DC mode was used for the formation of silicon as well as titanium doped diamond-like carbon films. Silicon oxide films were deposited by radio frequency magnetron sputtering. The results indicate a strong influence of nanoporosity on the oxygen transmission rate for all coating types, while the low content of microporosity (particulates, etc. is shown to be of lesser importance. Due to the low thickness of the foil substrates, being easily bent, the toughness as a measure of tendency to film fracture together with the elasticity index of the thin films influence the oxygen barrier. All investigated coatings are non-pyrogenic, cause no cytotoxic effects and do not influence bacterial growth.

  16. Structure analysis of silicon-doped diamond-like carbon films by X-ray and neutron reflectivity measurements

    International Nuclear Information System (INIS)

    Diamond-like carbon (DLC) is an amorphous material with an intermediate chemical structure between diamond and graphite. While the DLC coatings show low friction and little wear, the tribological properties are improved by doping of silicon. Since the effect of the silicon on the improvement is not unveiled, we coated silicon wafers with Si-doped DLC (DLC-Si) films by direct-current plasma CVD process, evaluated their friction coefficient and wear depth, and investigated the cross-section profiles of the films. Ball-on-disk test revealed that the tribological properties improved most when silicon is added by 6-10 at.% against carbon in the DLC-Si films. X-ray reflectometry suggested the existence of a thin layer with a different scattering length density (SLD) on the surfaces of the DLC-Si films. The thickness of the layers is around 20 nm. Neutron reflectivity measurements confirmed the formation similar SLD structure, the composition and mass density of the films. It is concluded that the surface thin layers, which are not observed for a DLC film free from or without silicon, should be responsible for the enhanced tribological properties. (author)

  17. Investigation of electrically-active deep levels in single-crystalline diamond by particle-induced charge transient spectroscopy

    Science.gov (United States)

    Kada, W.; Kambayashi, Y.; Ando, Y.; Onoda, S.; Umezawa, H.; Mokuno, Y.; Shikata, S.; Makino, T.; Koka, M.; Hanaizumi, O.; Kamiya, T.; Ohshima, T.

    2016-04-01

    To investigate electrically-active deep levels in high-resistivity single-crystalline diamond, particle-induced charge transient spectroscopy (QTS) techniques were performed using 5.5 MeV alpha particles and 9 MeV carbon focused microprobes. For unintentionally-doped (UID) chemical vapor deposition (CVD) diamond, deep levels with activation energies of 0.35 eV and 0.43 eV were detected which correspond to the activation energy of boron acceptors in diamond. The results suggested that alpha particle and heavy ion induced QTS techniques are the promising candidate for in-situ investigation of deep levels in high-resistivity semiconductors.

  18. Localization of dislocation-related luminescence centers in self-ion implanted silicon and effect of additional boron ion doping

    Energy Technology Data Exchange (ETDEWEB)

    Tetelbaum, D.I.; Mikhaylov, A.N.; Belov, A.I.; Korolev, D.S.; Shushunov, A.N.; Bobrov, A.I.; Pavlov, D.A. [Lobachevsky State University of Nizhni Novgorod (Russian Federation); Shek, E.I.; Sobolev, N.A. [Ioffe Physical Technical Institute, St. Petersburg (Russian Federation)

    2015-01-01

    The depth distribution of light-emitting centers of the D1 dislocation-related photoluminescence line (∝ 1.5 μm) in silicon implanted with Si{sup +} ions and annealed at 1100 C in the oxidizing chlorine-containing atmosphere has been investigated by means of the layer-by-layer chemical etching. It is established with the application of cross-sectional transmission electron microscopy that the main contribution to the D1 line is made by the centers located at the depths of up to ∝ 150 nm, i.e. in the region of Si{sup +} ion ranges, whereas the dislocations produced by Si{sup +} implantation and annealing at 1100 C penetrate to the depth of ∝ 1000 nm. Additional boron ion doping with subsequent annealing at 800 C in N{sub 2} atmosphere improves the emission in comparison with the undoped but annealed reference sample, however the additional annealing at 800 C per se results in the photoluminescence weakening. The dependence of the D1 line intensity on boron ion dose is found to be nonmonotonous. The interpretation of the obtained results is given in relation to the key role of selfinterstitials and boron impurity in the formation of radiative and nonradiative centers. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. Study of Nitrogen Effect on the Boron Diffusion during Heat Treatment in Polycrystalline Silicon/Nitrogen-Doped Silicon Thin Films

    Science.gov (United States)

    Saci, Lynda; Mahamdi, Ramdane; Mansour, Farida; Boucher, Jonathan; Collet, Maéva; Bedel Pereira, Eléna; Temple-Boyer, Pierre

    2011-05-01

    The present paper studies the boron (B) diffusion in nitrogen (N) doped amorphous silicon (a-Si) layer in original bi-layer B-doped polycrystalline silicon (poly-Si)/in-situ N-doped Si layers (NIDOS) thin films deposited by low pressure chemical vapor deposition (LPCVD) technique. The B diffusion in the NIDOS layer was investigated by secondary ion mass spectrometry (SIMS) and Fourier transform infrared spectroscopy (FTIR) analysis. A new extended diffusion model is proposed to fit the SIMS profile of the bi-layer films. This model introduces new terms which take into account the effect of N concentration on the complex diffusion phenomena of B atoms in bi-layer films. SIMS results show that B diffusion does not exceed one third of NIDOS layer thickness after annealing. The reduction of the B diffusion in the NIDOS layer is due to the formation of complex B-N as shown by infrared absorption measurements. Electrical measurements using four-probe and Hall effect techniques show the good conductivity of the B-doped poly-Si layer after annealing treatment.

  20. Fabrication and characterization of an all-diamond tubular flow microelectrode for electroanalysis.

    Science.gov (United States)

    Hutton, Laura A; Vidotti, Marcio; Iacobini, James G; Kelly, Chris; Newton, Mark E; Unwin, Patrick R; Macpherson, Julie V

    2011-07-15

    The development of the first all-diamond hydrodynamic flow device for electroanalytical applications is described. Here alternate layers of intrinsic (insulating), conducting (heavily boron doped), and intrinsic polycrystalline diamond are grown to create a sandwich structure. By laser cutting a hole through the material, it is possible to produce a tubular flow ring electrode of a characteristic length defined by the thickness of the conducting layer (for these studies ∼90 μm). The inside of the tube can be polished to 17 ± 10 nm surface roughness using a diamond impregnanted wire resulting in a coplanar, smooth, all-diamond surface. The steady-state limiting current versus volume flow rate characteristics for the one electron oxidation of FcTMA(+) are in agreement with those expected for laminar flow in a tubular electrode geometry. For dopamine detection, it is shown that the combination of the reduced fouling properties of boron doped diamond, coupled with the flow geometry design where the products of electrolysis are washed away downstream of the electrode, completely eradicates fouling during electrolysis. This paves the way for incorporation of this flow design into online electroanalytical detection systems. Finally, the all diamond tubular flow electrode system described here provides a platform for future developments including the development of ultrathin ring electrodes, multiple apertures for increased current response, and multiple, individually addressable ring electrodes incorporated into the same flow tube.

  1. Dopant deactivation and annealing characteristics of metal-oxide-semiconductor structures on germanium/boron-doped silicon after gamma irradiation or Fowler--Nordheim charge injection

    Energy Technology Data Exchange (ETDEWEB)

    Hashemipour, O.; Ang, S.S.; Brown, W.D.; Yeargan, J.R. (Department of Electrical Engineering, 3217 Bell Engineering Center, University of Arkansas, Fayetteville, Arkansas 72701 (USA)); West, L. (Department of Mechanical Engineering, University of Arkansas, Fayetteville, Arkansas 72701 (USA))

    1991-08-01

    Dopant deactivation and thermal annealing characteristics of metal-oxide-semiconductor capacitors fabricated on Ge/B-doped silicon after gamma irradiation or Fowler--Nordheim injection were investigated for the first time. A decrease of about 30% in active acceptor concentration was observed immediately after gamma irradiation or Fowler--Nordheim injection. Further deactivation of boron ({similar to}20%) occurred with annealing for temperatures of 80 {degree}C and higher. Hydrogen for the deactivation, which occurred during annealing, is thought to come from dissociation of weakly bonded Ge---H formed during the gamma irradiation or Fowler--Nordheim injection. Capacitors fabricated on conventional boron-doped substrates do not exhibit acceptor deactivation as a result of annealing following irradiation or injection. For annealing temperatures of 110 {degree}C and higher, the boron is first deactivated by the process noted above, and then is apparently reactivated by the dissociation of B---H bonds with hydrogen evolution from the structure.

  2. Space-Confined Synthesis of Three-Dimensional Boron/Nitrogen-Doped Carbon Nanotubes/Carbon Nanosheets Line-in-Wall Hybrids and Their Electrochemical Energy Storage Applications

    DEFF Research Database (Denmark)

    Zhu, Shan; Li, Jiajun; Li, Qingfeng;

    2016-01-01

    This research demonstrates a flexible one-pot strategy for fabricating three-dimensional (3D) boron/nitrogen-doped networks of carbon nanotubes(CNTs)/carbon nanosheets "Line-in-Wall" hybrids (LIWNB) based on the space-confined template method. In the synthesis, the high rate of freezing step and ...

  3. What is the significance of nitrogen-vacancy centers in the doping into diamond?

    International Nuclear Information System (INIS)

    In order to advance quantum computer after successful synthesis of a qubit (quantum-bit) using a NV (nitrogen-vacancy) center in diamond crystal, the innovation of a NOT processor is strongly demanded. A candidate of it can be one NV center associated with an additional N atom, which is called a NV-N center. Making use of a classical molecular dynamics simulation of N ion implantation into pure diamond with an energy of 200 eV, we have examined the crystallographic structure of 'NV-N' centers. However, at low temperature of 30 K, most implanted N atoms became interstitials, thus it was difficult to identify even NV centers.

  4. Diamond nanophotonics

    Directory of Open Access Journals (Sweden)

    Katja Beha

    2012-12-01

    Full Text Available We demonstrate the coupling of single color centers in diamond to plasmonic and dielectric photonic structures to realize novel nanophotonic devices. Nanometer spatial control in the creation of single color centers in diamond is achieved by implantation of nitrogen atoms through high-aspect-ratio channels in a mica mask. Enhanced broadband single-photon emission is demonstrated by coupling nitrogen–vacancy centers to plasmonic resonators, such as metallic nanoantennas. Improved photon-collection efficiency and directed emission is demonstrated by solid immersion lenses and micropillar cavities. Thereafter, the coupling of diamond nanocrystals to the guided modes of micropillar resonators is discussed along with experimental results. Finally, we present a gas-phase-doping approach to incorporate color centers based on nickel and tungsten, in situ into diamond using microwave-plasma-enhanced chemical vapor deposition. The fabrication of silicon–vacancy centers in nanodiamonds by microwave-plasma-enhanced chemical vapor deposition is discussed in addition.

  5. Corrosion behavior of aluminum doped diamond-like carbon thin films in NaCl aqueous solution.

    Science.gov (United States)

    Khun, N W; Liu, E

    2010-07-01

    Aluminum doped diamond-like carbon (DLC:Al) thin films were deposited on n-Si(100) substrates by co-sputtering a graphite target under a fixed DC power (650 W) and an aluminum target under varying DC power (10-90 W) at room temperature. The structure, adhesion strength and surface morphology of the DLC:Al films were characterized by X-ray photoelectron spectroscopy (XPS), micro-scratch testing and atomic force microscopy (AFM), respectively. The corrosion performance of the DLC:Al films was investigated by means of potentiodynamic polarization testing in a 0.6 M NaCl aqueous solution. The results showed that the polarization resistance of the DLC:Al films increased from about 18 to 30.7 k(omega) though the corrosion potentials of the films shifted to more negative values with increased Al content in the films. PMID:21128496

  6. Structural characteristics of surface-functionalized nitrogen-doped diamond-like carbon films and effective adjustment to cell attachment

    Science.gov (United States)

    Liu, Ai-Ping; Liu, Min; Yu, Jian-Can; Qian, Guo-Dong; Tang, Wei-Hua

    2015-05-01

    Nitrogen-doped diamond-like carbon (DLC:N) films prepared by the filtered cathodic vacuum arc technology are functionalized with various chemical molecules including dopamine (DA), 3-Aminobenzeneboronic acid (APBA), and adenosine triphosphate (ATP), and the impacts of surface functionalities on the surface morphologies, compositions, microstructures, and cell compatibility of the DLC:N films are systematically investigated. We demonstrate that the surface groups of DLC:N have a significant effect on the surface and structural properties of the film. The activity of PC12 cells depends on the particular type of surface functional groups of DLC:N films regardless of surface roughness and wettability. Our research offers a novel way for designing functionalized carbon films as tailorable substrates for biosensors and biomedical engineering applications. Project supported by the National Natural Science Foundation of China (Grant Nos. 51272237, 51272231, and 51010002) and the China Postdoctoral Science Foundation (Grant Nos. 2012M520063, 2013T60587, and Bsh1201016).

  7. First-principles study of metallic carbon nanotubes with boron/nitrogen co-doping

    Institute of Scientific and Technical Information of China (English)

    Chen Ling-Na; Ma Song-Shan; OuYang Fang-Ping; Xiao Jin; Xu Hui

    2011-01-01

    Using the first-principles calculations, we investigate the electronic band structure and the quantum transport properties of metallic carbon nanotubes (MCNTs) with B/N pair co-doping. The results about formation energy show that the B/N pair co-doping configuration is a most stable structure. We find that the electronic structure and the transport properties are very sensitive to the doping concentration of the B/N pairs in MCNTs, where the energy gaps increase with doping concentration increasing both along the tube axis and around the tube, because the mirror symmetry of MCNT is broken by doping B/N pairs. In addition, we discuss conductance dips of the transmission spectrum of doped MCNTs. These unconventional doping effects could be used to design novel nanoelectronic devices.

  8. Influence of Boron doping on the structural, optical and electrical properties of CdO thin films by spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Velusamy, P., E-mail: rampap2k@yahoo.co.in; Babu, R. Ramesh, E-mail: rampap2k@yahoo.co.in [Crystal Growth and Thin Films Laboratory, Department of Physics, Bharathidasan University, Tiruchirappalli- 620024, Tamil Nadu (India); Ramamurthi, K. [Department of Physics and Nanotechnology, Faculty of Engineering and Technology, SRM University, Kattankulathur - 603203, Tamil Nadu (India)

    2014-04-24

    Cadmium oxide and Boron (B) doped Cadmium oxide thin films were deposited using spray pyrolysis technique. The structural, morphological, electrical and optical properties of undoped and B doped CdO films are analyzed by varying the dopant concentration in the solution. The structural study shows the polycrystalline nature and cubic structure of undoped and B doped CdO thin films. Surface morphological study reveals that the grains are spherical in shape. Optical and electrical studies showed n-type semiconducting nature and optical band gap of 2.44 eV of deposited thin films.

  9. Polycrystalline-Diamond MEMS Biosensors Including Neural Microelectrode-Arrays

    Directory of Open Access Journals (Sweden)

    Donna H. Wang

    2011-08-01

    Full Text Available Diamond is a material of interest due to its unique combination of properties, including its chemical inertness and biocompatibility. Polycrystalline diamond (poly-C has been used in experimental biosensors that utilize electrochemical methods and antigen-antibody binding for the detection of biological molecules. Boron-doped poly-C electrodes have been found to be very advantageous for electrochemical applications due to their large potential window, low background current and noise, and low detection limits (as low as 500 fM. The biocompatibility of poly-C is found to be comparable, or superior to, other materials commonly used for implants, such as titanium and 316 stainless steel. We have developed a diamond-based, neural microelectrode-array (MEA, due to the desirability of poly-C as a biosensor. These diamond probes have been used for in vivo electrical recording and in vitro electrochemical detection. Poly-C electrodes have been used for electrical recording of neural activity. In vitro studies indicate that the diamond probe can detect norepinephrine at a 5 nM level. We propose a combination of diamond micro-machining and surface functionalization for manufacturing diamond pathogen-microsensors.

  10. Boron/nitrogen pairs Co-doping in metallic carbon nanotubes: a first-principle study

    Institute of Scientific and Technical Information of China (English)

    Ouyang Fang-Ping; Peng Sheng-Lin; Chen Ling-Na; Sun Shu-Yuan; Xu Hui

    2011-01-01

    By using the first-principles calculations, the electronic structure and quantum transport properties of metallic carbon nanotubes with B/N pairs co-doping have been investigated. It is shown that the total energies of metallic carbon nanotubes are sensitive to the doping sites of the B/N pairs. The energy gaps of the doped metallic carbon nanotubes decrease with decreasing the concentration of the B/N pair not only along the tube axis but also around the tube. Moreover, the I-V characteristics and transmissions of the doped tubes are studied. Our results reveal that the conducting ability of the doped tube decreases with increasing the concentrations of the B/N pairs due to symmetry breaking of the system. This fact opens a new way to modulate band structures of metallic carbon nanotubes by doping B/N pair with suitable concentration and the novel characteristics are potentially useful in future applications.

  11. Growth of boric acid crystallites on the surface of boron-doped silicon carbide samples

    International Nuclear Information System (INIS)

    White crystallites were visually observed on fractured or polished surfaces of SiC samples (grain sizes below ∼500 nm) during exposure to air at room temperature for several days. Characterization of the crystallites by scanning electron microscopy, secondary ion mass spectroscopy, and X-ray diffraction identified B(OH)3 crystals with a strong (002) texture. The rate of boric acid formation was determined by a gravimetric experiment. The rate of weight gain increased significantly after an incubation period of 1 week. Nucleation is initially the rate-limiting process. Subsequently small B(OH)3 crystals form on the surface, whose growth rate is determined by grain boundary diffusion of boron to the SiC surface. An estimated grain boundary boron to the SiC surface. An estimated grain boundary diffusion coefficient of boron in SiC was many orders of magnitude higher than extrapolated literature values

  12. Nanoscale control of rewriteable doping patterns in pristine graphene/boron nitride heterostructures

    OpenAIRE

    Velasco Jr., Jairo; Ju, Long; Wong, Dillon; Kahn, Salman; Lee, Juwon; Tsai, Hsin-Zon; Germany, Chad; Wickenburg, Sebastian; Lu, Jiong; Taniguchi, Takashi; Watanabe, Kenji; Zettl, Alex; Wang, Feng; Crommie, Michael F.

    2016-01-01

    Nanoscale control of charge doping in two-dimensional (2D) materials permits the realization of electronic analogs of optical phenomena, relativistic physics at low energies, and technologically promising nanoelectronics. Electrostatic gating and chemical doping are the two most common methods to achieve local control of such doping. However, these approaches suffer from complicated fabrication processes that introduce contamination, change material properties irreversibly, and lack flexible ...

  13. Comparative surface and nano-tribological characteristics of nanocomposite diamond-like carbon thin films doped by silver

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Han-Shen; Endrino, Jose L.; Anders, Andre

    2008-07-10

    In this study we have deposited silver-containing hydrogenated and hydrogen-free diamond-like carbon (DLC) nanocomposite thin films by plasma immersion ion implantation-deposition methods. The surface and nano-tribological characteristics were studied by x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and nano-scratching experiments. The silver doping was found to have no measurable effect on sp2-sp3 hybridization of the hydrogenated DLC matrix and only a slight effect on the hydrogen-free DLC matrix. The surface topography was analyzed by surface imaging. High- and low-order roughness determined by AFM characterization was correlated to the DLC growth mechanism and revealed the smoothing effect of silver. The nano-tribological characteristics were explained in terms of friction mechanisms and mechanical properties in correlation to the surface characteristics. It was discovered that the adhesion friction was the dominant friction mechanism; the adhesion force between the scratching tip and DLC surface was decreased by hydrogenation and increased by silver doping.

  14. Effects of nitrogen content on structure and electrical properties of nitrogen-doped fluorinated diamond-like carbon films

    Institute of Scientific and Technical Information of China (English)

    XIAO Jian-rong; LI Xin-hai; WANG Zhi-xing

    2009-01-01

    Nitrogen-doped fluorinated diamond-like carbon (FN-DLC) films were prepared on single crystal silicon substrate by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) under different deposited conditions with CF4,CH4 and nitrogen as source gases.The influence of nitrogen content on the structure and electrical properties of the films was studied.The films were investigated in terms of surface morphology,microstructure,chemical composition and electrical properties.Atomic force microscopy (AFM) results revealed that the surface morphology of the films became smooth due to doping nitrogen.Fourier transform infrared absorption spectrometry (FTIR) results showed that amouts of C=N and C≡N bonds increased gradually with increasing nitrogen partial pressure r (r=p(N_2)/p(N_2+CF_4+CH_4)).Gaussian fit results of C 1s and N 1s in X-ray photoelectron spectra (XPS) showed that the incorporation of nitrogen presented mainly in the forms of β-C_3N_4 and a-CN_x (x=1,2,3) in the films.The current-voltage (I-V) measurement results showed that the electrical conductivity of the films increased with increasing nitrogen content.

  15. Effect of reaction conditions on methyl red degradation mediated by boron and nitrogen doped TiO2

    Science.gov (United States)

    Galenda, A.; Crociani, L.; Habra, N. El; Favaro, M.; Natile, M. M.; Rossetto, G.

    2014-09-01

    Nowadays the employment of renewable and sustainable energy sources, and solar light as main option, becomes an urgent need. Photocatalytic processes received great attention in wastewater treatment due to their cheapness, environmental compatibility and optimal performances. Despite the general low selectivity of the photocatalysts, an accurate optimisation of the operational parameters needs to be carried out in order to maximise the process yield. Because of this reason, the present contribution aims to deepen either the knowledge in boron and/or nitrogen doped TiO2-based systems and their employment in methyl red removal from aqueous solutions. The samples were obtained by coprecipitation and characterised by XRD, SEM, BET specific surface area, UV-vis and XPS techniques. The catalytic activity was for the first time carefully evaluated with respect to methyl red photodegradation in different conditions as a function of working pH, counter-ions and pre-adsorption time. An ad-hoc study was performed on the importance of the pre-adsorption of the dye, suggesting that an extended adsorption is useless for the catalyst photoactivity, while a partial coverage is preferable. The photocatalytic tests demonstrate the positive influence of boron doping in photo-activated reactions and the great importance of the operational parameters with respect to the simple methyl red bleaching rather than the overall pollutant mineralisation. It is proved, indeed, that different working pH, acidifying means and substrate pre-adsorption time can enhance or limit the catalyst performances with respect to the complete pollutant degradation rather than its partial breakage.

  16. Photoluminescence and Raman Spectroscopy Characterization of Boron- and Nitrogen-Doped 6H Silicon Carbide

    DEFF Research Database (Denmark)

    Ou, Yiyu; Jokubavicius, Valdas; Liu, Chuan;

    2012-01-01

    in an increased luminescence. A dopant concentration difference larger than 4x1018 cm-3 is proposed to achieve intense photoluminescence. Raman spectroscopy further confirmed the doping type and concentrations for the samples. The results indicate that N-B doped SiC is being a good wavelength converter in white...

  17. Control of Rewriteable Doping Patterns in Graphene/Boron Nitride Heterostructures

    Science.gov (United States)

    Kahn, Salman; Velasco, Jairo, Jr.; Wong, Dillon; Lee, Juwon; Tsai, Hsin Zon; Ju, Long; Jiang, Lili; Shi, Zhiwen; Ashby, Paul; Taniguchi, Takashi; Watanabe, Kenji; Zettl, Alex; Wang, Feng; Crommie, Michael

    Spatial control of charge doping in 2D materials is a promising technique for designing future electronic devices and understanding novel physics. Electrostatic gating and chemical doping are common methods to achieve control of charge doping in 2D materials. However, these approaches suffer from complicated fabrication processes that introduce impurities, change material properties irreversibly, and lack flexibility. Here, we introduce a new method for patterning rewriteable doping profiles with local interface charge transfer from defects in a tunable BN substrate into an adjacent layer of graphene. We characterize these spatial doping patterns through local probe and transport techniques. This technique enables many novel device designs for 2D materials, including atomically thin p-n junctions and rewriteable memory devices.

  18. Theoretical study of interaction between Tacrine and finite-length Al-doped Carbon and Boron nitride Nanotubes: A Semiempirical drug delivery study in thermodynamic view

    Directory of Open Access Journals (Sweden)

    Nasrin Zeighami

    2014-12-01

    Full Text Available In order to extend our previous theoretical calculations that dealt with the thermochemistry of doping the single walled boron nitride nano tubes, BNNTs, and carbon nanotubes ,CNTs, with alminium atoms [1], we have used the AM 1, PM 3, and PM 6 semiempirical methods to investigate the interaction of the tacrine molecule (a drug for the treatment of Alzheimer's disease with the side-walls of aluminum doped boron nitride and carbon nano tubes in thermodynamic views.At first, the frequency calculations were carried out to confirm the stability of the involved structures. In addition, the theoretical thermodynamic study of tacrine adsorption onto the considered nanotubes was performed and the thermodynamic functions such as enthalpy changes, entropy changes and Gibbs free energy changes of the adsorption process were evaluated at different temperatures. Our results suggest the aluminum doped boron nitride nano tubes and alminium doped carbon nano tubes may be considered as the proper carries for the drug delivery of tacrine.

  19. Influence of surface properties on the quantum photoyield of diamond photocathodes

    Energy Technology Data Exchange (ETDEWEB)

    Foord, J.S.; Wang, J.; Lau, C.H.; Hiramatsu, M.; Vickers, J. [Oxford Univ. (United Kingdom). Physical and Theoretical Chemistry Lab.; Jackman, R.B. [University Coll., London (United Kingdom). Dept. of Electrical and Electronic Engineering

    2001-07-23

    The quantum efficiency and chemical stability of CVD diamond photocathodes has been examined. As-grown or microwave plasma hydrogenated boron-doped diamond films display a quantum photoyield of approximately 0.05% at 190 nm, which degrades gradually as the material is left in ambient atmosphere, due to slow oxidation. Rapid degradation in performance occurs when exposed to atomic or electronically excited oxygen. X-ray photoelectron spectroscopy shows that the yield drops close to zero at around monolayer oxygen coverage, and that the main oxygen species on the surface is hydroxyl or isolated ether linkages. (orig.)

  20. Photo-stimulated low electron temperature high current diamond film field emission cathode

    Science.gov (United States)

    Shurter; Roger Philips , Devlin; David James , Moody; Nathan Andrew , Taccetti; Jose Martin , Russell; Steven John

    2012-07-24

    An electron source includes a back contact surface having a means for attaching a power source to the back contact surface. The electron source also includes a layer comprising platinum in direct contact with the back contact surface, a composite layer of single-walled carbon nanotubes embedded in platinum in direct contact with the layer comprising platinum. The electron source also includes a nanocrystalline diamond layer in direct contact with the composite layer. The nanocrystalline diamond layer is doped with boron. A portion of the back contact surface is removed to reveal the underlying platinum. The electron source is contained in an evacuable container.

  1. Characterization of phosphorus-doped homoepitaxial (1 0 0) diamond films grown using high-power-density MWPCVD method with a conventional quartz-tube chamber

    International Nuclear Information System (INIS)

    Phosphorus-doped n-type homoepitaxial diamond films have been successfully grown at high substrate temperatures (>1000 deg. C) on high-pressure/high-temperature-synthesized type-Ib single-crystalline diamond (1 0 0) substrates, by using a conventional microwave plasma chemical-vapor-deposition (CVD) system with high power densities. The deposition system employed in this work had an easily exchangeable 36 mm inner-diameter quartz-tube growth chamber. The homoepitaxial diamond films thus grown were characterized by means of Hall-effect measurements with an AC magnetic field, atomic force microscope observations and secondary ion mass spectrometry techniques. The dependences of the substrate temperature (≤1300 deg. C) and the P/C ratio in the source gas (≤9900 ppm) on the specimen features were investigated. The optimum substrate temperature deduced was ∼1160 deg. C, which was also applicable to the CVD growth of undoped homoepitaxial diamond layers. The n-type conductions with an activation energy ∼0.6 eV were observed for the specimens with amounts of the P atoms incorporated to ∼1.5 x 1018 cm-3 whereas the doping efficiencies changed from ∼0.06% to ∼0.92% with the growth condition. Possible origins for these results are discussed in relation to the growth mechanism

  2. Ion and electron bombardment-related ion emission during the analysis of diamond using secondary ion mass spectrometry

    International Nuclear Information System (INIS)

    In recent years, the ability to grow single crystal layers of both doped and pure diamonds has improved, and devices for applications in high power electronics and microelectronics are being developed, most of them based on boron doped diamond. In this work, convoluted angular and energy spectra (so-called secondary ion mass spectrometry energy spectra) have been measured for 11B+, 12C+, 16O+, CO+ and CO2+ ions ejected from a single crystal boron doped diamond layer under ultralow energy oxygen and electron beam bombardment. A low energy tail was observed in the 12C+, CO+, and CO2+ signals, corresponding to ions produced in the gas phase. Changing the bombardment conditions, we have identified interaction with the electron beam as the main ionization mechanism. In the case of 12C+ it appears that the gas phase ions are produced by electron stimulated desorption and postionization of surface species created by the oxygen beam. We have detected high signals for CO+ and CO2+ ionized in the gas phase, which supports a mechanism previously suggested to explain the anomalously fast diamond erosion under oxygen ion beam bombardment. We also observe that some species appearing in the mass spectrum are produced by electron stimulated desorption and this needs to be remembered when analyzing these on insulating diamond with charge compensation

  3. Boron-Doped Graphene As Active Electrocatalyst For Oxygen Reduction Reaction At A Fuel-Cell Cathode

    CERN Document Server

    Fazio, Gianluca; Di Valentin, Cristiana

    2016-01-01

    Boron-doped graphene was reported to be the best non-metal doped graphene electrocatalyst for the oxygen reduction reaction (ORR) working at an onset potential of 0.035 V [JACS 136 (2014) 4394]. In the present DFT study, intermediates and transition structures along the possible reaction pathways are determined. Both Langmuir-Hinschelwood and Eley-Rideal mechanisms are discussed. Molecular oxygen binds the positively charged B atom and forms an open shell end-on dioxygen intermediate. The associative path is favoured with respect to the dissociative one. The free energy diagrams along the four-reduction steps are investigated with the methodology by N{\\o}rskov and co. [JPC B 108 (2004) 17886] in both acidic and alkaline conditions. The pH effect on the stability of the intermediates of reduction is analyzed in terms of the Pourbaix diagram. At pH = 14 we compute an onset potential value for the electrochemical ORR of U = 0.05 V, which compares very well with the experimental value in alkaline conditions.

  4. Fullerenes as alternative acceptors by transfer doping of diamond surfaces; Fullerene als alternative Akzeptoren bei der Transferdotierung von Diamantoberflaechen

    Energy Technology Data Exchange (ETDEWEB)

    Strobel, Paul

    2008-06-06

    The topic of this thesis is the fullerene induced surface conductivity on hydrogen terminated diamond. A systematic investigation of C{sub 60}, C{sub 60}F{sub 18}, C{sub 60}F{sub 36} and C{sub 60}F{sub 48} as transfer dopants on hydrogenated diamond has been performed. For C{sub 60}, the doping mechanism is more accurately described as a charge exchange in an extreme type II heterojunction. On the other hand a molecular surface acceptor model that takes the degeneracy of holes and the electric field caused by charge separation into account has been performed for the case of C{sub 60}F{sub 48} in excellent agreement with experimental results. Using in situ Hall Effect measurements of air, C{sub 60}, and C{sub 60}F{sub 48} induced conductivity the sign of the charge carriers that dominate the transport properties was determined. At ambient temperature the hole mobility {mu} as a function of the induced charge carrier density p between p=5.10{sup 10} cm{sup -2} and p=3.10{sup 13} cm{sup -2} was measured. A maximum of the mobility of 130-150 cm{sup 2}V{sup -1}s{sup -1} occurs for p=2.10{sup 1} cm{sup -2}. Temperature dependent Hall measurements between 77 and 350 K show a non-activated, constant charge carrier density on all examinated samples, independently of the kind of adsorbates. On the other hand, both the conductivity and the mobility exhibit temperature dependence, varying with the charge carrier concentration. An essential part of this thesis addressed the investigation and the improvement of the thermal stability of the fullerene layers. In order to achieve the covalent attachment of C{sub 60}F{sub 48} to a hydrogen terminated diamond surface a process for controlled partially hydrolisation was developed. Functionalization with hydroxyl groups could be achieved by using a remote water vapour plasma at room temperature for a few seconds as demonstrated by photoelectron spectroscopy. Prolonged water plasma exposure, however, as well as annealing at temperatures

  5. Tuning electronic properties of carbon nanotubes by Boron and Nitrogen doping

    Science.gov (United States)

    Chegel, Raad

    2016-10-01

    The electronic properties of pure and doped carbon nanotubes and NC3-, BC3-, NC- and BC-nanotubes are investigated by using tight binding theory. It was found that applying the external fields and doping change the band gap. The energy gap is reduced by B/N-doping and the reduction value is sensitive to the several parameters such as nanotube diameter and chirality, external field strength, electric field direction, impurity type and concentration. The direct N (B) substitution creates a new band above (below) the Fermi level and leads to creation of n-type (p-type) semiconductor. The external fields modify the band structure and convert the doped nanotube into metal. For both XC and XC3 nanotubes (X=B/N), the gap energy reduction shows identical dependence to electric field and the XC3 nanotubes show more sensitive behavior to electric field rather than XC nanotubes.

  6. Effects of heat-treatments on electrical properties of boron-doped silicon crystals

    OpenAIRE

    Kamiura, Y.; Hashimoto, F.; Yoneta, M.

    1990-01-01

    The effects of heat-treatments around 1000°Cand subsequent annealing on the electrical properties of boron-dopedsilicon have been studied by electrical conductivity, Hall effect, and deep-level transient spectroscopy measurements. Thehigh-temperature heat-treatments always induced net densities of donors. Four recovery stages, stages I-IV, of heat-treatment-induced donors were observed on isochronal annealing up to 400°C Conductivity changes in these stages can be explainedas described below ...

  7. Electro-Explosive Doping of VT6 Titanium Alloy Surface by Boron Carbide

    Science.gov (United States)

    Kobzareva, T. Yu; Gromov, V. E.; Ivanov, Yu F.; Budovskkh, E. A.; Konovalov, S. V.

    2016-09-01

    The studies carried out in this work target detection of changes in the surface layer of titanium alloy VT6 after electro-explosive alloying (EEA) by boron carbide. EEA of VT6 titanium alloy surface is the plasma alloying formed during the electric explosion of foil with the sample powder of boron carbide. Carbon fibers with weight 140 mg were used as an explosive conductor. Sample powder of boron carbide B4C was placed in the area of explosion on the carbon fibers. It was revealed that EEA of the surface layers of titanium alloy samples VT6 leads to the modification of the layer, thickness of which changes from 10 pm to 50 pm. Heterogeneous distribution of alloying elements was found in the treatment zone by the methods of X-ray microanalysis. A significant difference in their concentration in the identified layers leads to difference in their structural and tribological behaviour. It was revealed that after electro-explosive alloying the microhardness of titanium alloy VT6 significantly increases. Electro-explosive alloying leads to the formation of a structure of submicro- and nano-scale level. It allows strength and tribological properties of the treated surface to be increased.

  8. Boron Doped Nanocrystalline Film with Improved Work Function as a Buffer Layer in Thin Film Silicon Solar Cells.

    Science.gov (United States)

    Park, Jinjoo; Shin, Chonghoon; Park, Hyeongsik; Jung, Junhee; Lee, Youn-Jung; Bong, Sungjae; Dao, Vinh Ai; Balaji, Nagarajan; Yi, Junsin

    2015-03-01

    We investigated thin film silicon solar cells with boron doped hydrogenated nanocrystalline silicon/ hydrogenated amorphous silicon oxide [p-type nc-Si:H/a-SiOx:H] layer. First, we researched the bandgap engineering of diborane (B2H6) doped wide bandgap hydrogenated nanocryslline silicon (p-type nc-Si:H) films, which have excellent electrical properties of high dark conductivity, and low activation energy. The films prepared with lower doping ratio and higher hydrogen dilution ratio had higher optical gap (Eg), with higher dark conductivity (σ(d)), and lower activation energy (Ea). We controlled Eg from 2.10 eV to 1.75 eV, with σ(d) from 1.1 S/cm to 7.59 x 10(-3) S/cm, and Ea from 0.040 eV to 0.128 eV. Next, we focused on the fabrication of thin film silicon solar cells. By inserting p-type nc-Si:H film into the thin film silicon solar cells, we achieved a remarkable increase in the built-in potential from 0.803 eV to 0.901 eV. By forming p-type nc-Si:H film between SnO2:F/ZnO:Al (30 nm) and p-type a-SiOx:H layer, the solar cell properties of open circuit voltage (Voc), short circuit current density (Jsc), and efficiency (η) were improved by 3.7%, 9.2%, and 9.8%, respectively. PMID:26413646

  9. Preparation of boron-doped TiO{sub 2} films by autoclaved-sol method at low temperature and study on their photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Lu Xiaona; Tian Baozhu; Chen Feng [Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China); Zhang Jinlong, E-mail: jlzhang@ecust.edu.c [Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China); School of Chemistry and Materials Science, Guizhou Normal University, Guiyang 550001 (China)

    2010-10-29

    A series of uniform and transparent boron-doped TiO{sub 2} films were synthesized from autoclaved-sol without organic solvent at low temperature. As-prepared B-TiO{sub 2} films with two layers were characterized by XRD, DRS, XPS and AFM. The photocatalytic characteristics were measured based on the degradation of Rhodamine B (RhB) solution under visible or UV light. The results indicated that the anatase phase was the main crystal form of the films, containing a small amount of brookite. The presence of boron caused a red shift in the absorption band of TiO{sub 2} films. The doped boron was mainly presented in the form of B{sub 2}O{sub 3}, O-Ti-B and O-Ti-B bonds, confirming that autoclaved-sol synthesis at low temperature allowed for incorporation of boron atoms into the TiO{sub 2} matrix. Transmission of the films was about 90% in the visible region. The 10% (atom) B-TiO{sub 2} film exhibited the best photocatalytic activity both in visible and UV light.

  10. Adsorption of diazinon and hinosan molecules on the iron-doped boron nitride nanotubes surface in gas phase and aqueous solution: A computational study

    Science.gov (United States)

    Farmanzadeh, Davood; Rezainejad, Hamid

    2016-02-01

    In this study, the geometric structures and electronic properties of two widely used organophosphorus pesticides, diazinon and hinosan, boron nitride nanotubes (BNNTs) and Fe doped boron nitride nanotubes (FeBNNTs) as adsorbents of these pesticides are studied by density functional theory calculation as well as dispersion correction by Grimme method. The results show that Fe doping in boron nitride nanotubes structures increases the potency of nanotubes to adsorb mentioned pesticides, especially when Fe atom located instead of N atom. Comparing the adsorption energies of diazinon on FeBNNTs with ones for hinosan demonstrate that the adsorption of hinosan is energetically more favorable by FeBNNTs. Assessment of adsorption energies in aqueous solution confirmed significant decrease in their values compared to ones in gaseous phase. However, the adsorption of diazinon and hinosan on both BNNTs and FeBNNTs are exothermic. So, BNNTs and FeBNNTs may be promising candidates as appropriate adsorbents for adsorbing diazinon and hinosan. Also, the results of calculations have revealed that van der Waals interaction energies are remarkably large in adsorption of diazinon and hinosan on all boron nitride nanotubes.

  11. Effective performance for undoped and boron-doped double-layered nanoparticles-copper telluride and manganese telluride on tungsten oxide photoelectrodes for solar cell devices.

    Science.gov (United States)

    Srathongluan, Pornpimol; Vailikhit, Veeramol; Teesetsopon, Pichanan; Choopun, Supab; Tubtimtae, Auttasit

    2016-11-01

    This work demonstrates the synthesis of a novel double-layered Cu2-xTe/MnTe structure on a WO3 photoelectrode as a solar absorber for photovoltaic devices. Each material absorber is synthesized using a successive ionic layer adsorption and reaction (SILAR) method. The synthesized individual particle sizes are Cu2-xTe(17) ∼5-10nm and MnTe(3) ∼2nm, whereas, the aggregated particle sizes of undoped and boron-doped Cu2-xTe(17)/MnTe(11) are ∼50 and 150nm, respectively. The larger size after doping is due to the interconnecting of nanoparticles as a network-like structure. A new alignment of the energy band is constructed after boron/MnTe(11) is coated on boron/Cu2-xTe nanoparticles (NPs), leading to a narrower Eg equal to 0.58eV. Then, the valence band maximum (VBM) and conduction band minimum (CBM) with a trap state are also up-shifted to near the CBM of WO3, leading to the shift of a Fermi level for ease of electron injection. The best efficiency of 1.41% was yielded for the WO3/boron-doped [Cu2-xTe(17)/MnTe(11)] structure with a photocurrent density (Jsc)=16.43mA/cm(2), an open-circuit voltage (Voc)=0.305V and a fill factor (FF)=28.1%. This work demonstrates the feasibility of this double-layered structure with doping material as a solar absorber material. PMID:27451035

  12. Effects of glucose doping on the MgB2 superconductors using cheap crystalline boron

    Science.gov (United States)

    Parakkandy, Jafar Meethale; Shahabuddin, Mohammed; Shah, M. Shahabuddin; Alzayed, Nasser S.; Qaid, Salem A. S.; Madhar, Niyaz Ahmad; Ramay, Shahid M.; Shar, Muhammad Ali

    2015-12-01

    We report the effect of glucose (C6H12O6) doping on the structural and electromagnetic properties of MgB2 superconductor fabricated by dry mixing using planetary ball milling. Herein, as-prepared bulk polycrystalline Mg (B1-xCx) 2 samples with different doping levels (x = 0, 2, 4, and 6 at. %) were systematically studied by X-ray diffraction, magnetic and resistivity measurements, and microstructure analysis. When carbon doped, the reduction in critical transition temperature and shrinkage in a-lattice were obviously observed. This resulted in structural distortion of the MgB2 lattice, and thereby, enhanced an impurity scattering. In addition to these, upper critical field and high-field critical current densities were also enhanced. On the other hand, both pinning force and low-field critical current density are decreased. The high field enhancement and low field degradation are due to increase in impurity scattering and decrease in pinning force respectively.

  13. Deposition and field-emission characterization of electrically conductive nitrogen-doped diamond-like amorphous carbon films

    International Nuclear Information System (INIS)

    For the fabrication of high performance field emitters, diamond-like amorphous carbon films doped with nitrogen (DAC:N) were formed using an intermittent supermagnetron plasma chemical vapor deposition technique. DAC:N films were deposited using isobutane plasma to investigate the influence of discharge-off time and electrode spacing on the physical properties of the films at upper- and lower-electrode radio frequency (rf) powers (LORF) of 800 W/50-800 W. At LORF of 100 W, a discharge-on time of 1 min, and a discharge-off time (cooling time) of 30 s-10 min, resistivity was decreased with a decrease of the cooling time. By reducing the electrode spacing from 60 to 20 mm at a LORF of 50 and 800 W, the optical band gap of DAC:N film was decreased from 0.85 and 0.23 eV to 0.6 and 0 eV, respectively. A flat DAC:N film of 700 A thickness was deposited on a n-Si wafer at rf powers of 800 W/800 W. Using this flat DAC:N film, a threshold electric field of 18 V/μm was observed and maximum field-emission current density of 2.2 mA/cm2 was observed at the electric field of 32 V/μm

  14. Physical properties of nitrogen-doped diamond-like amorphous carbon films deposited by supermagnetron plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    Diamond-like amorphous carbon films doped with nitrogen (DAC:N) were deposited on Si and glass wafers intermittently using i-C4H10/N2 repetitive supermagnetron plasma chemical vapor deposition. Deposition duration, which is equal to a plasma heating time of wafer, was selected to be 40 or 60 s, and several layers were deposited repetitively to form one thick film. DAC:N films were deposited at a lower-electrode temperature of 100 deg. C as a function of upper- and lower-electrode rf powers (200 W/200 W-1 kW/1 kW) and N2 concentration (0%-80%). With an increase in N2 concentration and rf power, the resistivity and the optical band gap decreased monotonously. With increase of the deposition duration from 40 to 60 s, resistivity decreased to 0.03Ω cm and optical band gap decreased to 0.02 eV (substantially equal to 0 eV within the range of experimental error), at an N2 concentration of 80% and rf power of 1 kW(/1 kW)

  15. Electrical properties of diamond nanostructures

    Science.gov (United States)

    Bevilacqua, M.

    Nanocrystalline diamond films (NCD) can potentially be used in a large variety of applications such as electrochemical electrodes, tribology, cold cathodes, and corrosion resistance. A thorough knowledge of the electrical properties of NCD films is therefore critical to understand and predict their performance in various applications. In the present work the electrical properties of NCD films were analysed using Impedance Spectroscopy and Hall Effect measurements. Impedance Spectroscopy permits to identify and single out the conduction paths within the films tested. Such conduction paths can be through grain interiors and/or grain boundaries. Hall measurements, carried out on Boron doped NCD, permits determination of the mobility of the films. Specific treatments were devised to enhance the properties of the NCD films studied. Detonation nanodiamond (DND) is becoming an increasingly interesting material. It is already used as abrasive material or component for coatings [1], but its potential applications can extend far beyond these. It is therefore essential to understand the structure and electrical properties of DND in order to exploit the full potential of this material. In the present work, electrical properties of DND were studied using Impedance Spectroscopy. The results obtained suggest that DND could be used to manufacture devices able to work as Ammonia detectors. Another major area of study in this work was ultra-violet diamond photodetectors. Using high quality CVD single-crystal diamond, UV photodetection devices were built using standard lithographic techniques. Following the application of heat treatments, the photoconductive properties of these devices were highly enhanced. The devices represent the state-of-the-art UV diamond photodetectors.

  16. “Synthesis and properties of Boron doped ZnO thin films by spray CVD technique at low substrate temperature”

    Directory of Open Access Journals (Sweden)

    Sunanda C. Yadav

    2012-12-01

    Full Text Available Intrinsic and nanocrystalline properties of Boron doped ZnO thin films were synthesized with a newly designed spray CVD technique from non-aqueous solution of Zinc acetate [Zn(CH3COOH2] as a precursor solution and Boric Acid as a doping solution. The major benefits of this technique are precise stoichiometry and its ability to deposit vapors on a large surface area with a high uniformity of thickness. The commercialization potential is enhanced by the low deposition temperature. In view for providing thin films as a Transparent Conducting Oxide (TCO for commercial application, the effect of dopant concentration from 0.2 at% to 1 at% in steps of 0.2 has been studied. The crystalline properties of these films have been investigated by X- ray diffraction (XRD technique. The results reveal hexagonal wurtzite structure indicating preferential orientation along caxis. Debye –Scherrer calculation indicate deteriorated crystallinity induced by Boron doping. The results are inwell agreement with surface morphology of film analyzed with Field Emission Scanning Micrographs and topography of films characterized with AFM. Moreover, the Boron doping enhances optoelectronic properties. The average optical transmittance of films increases with doping concentration showing maximum transparency for 0.8at% doping concentration (≈90%. The transmittance curve indicates interference fringe pattern between the wave fronts generated at the two interfaces (air and substrate. The extinction coefficient of the films is nearly equal to zero which suggests there is no absorption of light at grain boundary. Boron doping results blue shifted optical band gap resulted with reduced particle size. Nevertheless, refractive index and absorption edge of the ZnO films are similar to that of single crystal ZnO. The significant effect indicating enhanced electrical conductivity of the ZnO film is observed for the optimized B dopant concentration (0.8 at %. The films obtained at

  17. 硼掺杂对石墨烯量子点发光影响的理论研究%Theoretical Study of the Fluorescence of Graphene Quantum Dots Doped by Boron

    Institute of Scientific and Technical Information of China (English)

    杨丽君

    2016-01-01

    The absorption and emission spectra of graphene quantum dots (GQDs)and boron-doped GQDs were ex-plored by TDDFT method.The calculated results indicate that the doped boron atom can make a high redshift of ab-sorption and emission wavelength of GQDs.The doped boron atom located at the edge of GQDs makes higher red-shift.The doped-boron atom also greatly decreases the absorption and emission intensity of GQDs,which is inde-pendent of the position of boron atom.The molecular orbitals of GQDs and boron-doped GQDs were analyzed.The transition is charge transfer (CT)when boron locates at the edge of GQDs,which is different from the local excita-tion (LE)of GQDs with interior doped boron.%采用含时密度泛函(TDDFT)方法研究了石墨烯量子点(GQDs)和硼掺杂 GQDs 的吸收和发射光谱。计算结果表明,硼掺杂使 GQDs 的吸收和发射光波长红移,硼的位置越靠近 GQDs 边缘,波长红移越多。硼掺杂极大地降低了 GQDs 的吸收和发射光强度,这与掺杂时硼的位置无关。轨道分析表明,硼掺杂在边缘时,GQDs 中电子跃迁的类型为电荷转移跃迁,与硼掺杂在晶格内的局域激发不同。

  18. Phosphorus- and boron-doped hydrogenated amorphous silicon films prepared using vaporized liquid cyclopentasilane

    Energy Technology Data Exchange (ETDEWEB)

    Masuda, Takashi, E-mail: mtakashi@jaist.ac.jp [Japan Advanced Institute of Science and Technology, Nomi, Ishikawa, 923-1292 (Japan); Takagishi, Hideyuki; Shen, Zhongrong; Ohdaira, Keisuke; Shimoda, Tatsuya [Japan Advanced Institute of Science and Technology, Nomi, Ishikawa, 923-1292 (Japan); Japan Science and Technology Agency, ALCA, Nomi, Ishikawa, 923-1211 (Japan)

    2015-08-31

    A simple, inexpensive method for fabricating a hydrogenated amorphous silicon (a-Si:H) film using thermal chemical vapor deposition from cyclopentasilane (CPS) at atmospheric pressure with a substrate temperature of 370 °C is described. The reactant gas was generated from liquid CPS by vaporization in the deposition chamber. The vaporized CPS gas was transformed immediately into a-Si:H film on a heated substrate. The a-Si:H films could be doped either n- or p-type by dissolving appropriate amounts of white phosphorus or decaborane, respectively, in the liquid CPS before vaporization. This process allows deposition of doped a-Si:H films of photovoltaic device-quality without the need for handling, storage, or transportation of large amounts of gaseous reactants. - Highlights: • B and P doped a-Si:H films made from liquid materials is presented. • Decaborane and white phosphorus is dissolved in the liquid materials. • A simple, inexpensive method for fabricating a-Si:H films using non-vacuum process. • The doped a-Si:H films with usable quality for photovoltaic devices are deposited.

  19. Boron and aluminium doping in SiC and its passivation by hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Deak, Peter; Aradi, Balint; Gali, Adam [Budapest University of Technology and Economics, Department of Atomic Physics, Budapest (Hungary)]. E-mail: p.deak@eik.bme.hu

    2001-10-08

    Extensive calculations regarding the formation energy of interstitial hydrogen and hydrogen-vacancy complexes in different charge states have been carried out using the local density approximation to ab initio density functional theory with a plane-wave basis and norm-conserving pseudopotentials on supercells of cubic (3C) SiC. Based on these results the hydrogen concentration of as-grown or H-plasma treated SiC is estimated and its effect on the net carrier concentration is given. Incorporation of B and Al in or without the presence of hydrogen has been investigated in hexagonal (4H) SiC supercells. The possible origins of the shallow and deep boron acceptors is discussed. It is found that the presence of boron promotes hydrogen incorporation during growth in the form of passive B+H complexes. The same is not true for Al. If Al+H complexes are formed (say, after H-plasma treatment), the structure of this complex is different from that of the B+H complexes. The calculated difference between the dissociation energies is 0.9 eV. (author)

  20. Diamond electronic properties and applications

    CERN Document Server

    Kania, Don R

    1995-01-01

    The use of diamond in electronic applications is not a new idea, but limitations in size and control of properties restricted the use of diamond to a few specialised applications. The vapour-phase synthesis of diamond, however, has facilitated serious interest in the development of diamond-based electronic devices. The process allows diamond films to be laid down over large areas. Both intrinsic and doped diamond films have a unique combination of extreme properties for high speed, high power and high temperature applications. The eleven chapters in Diamond: Electronic Properties and Applications, written by the world's foremost experts on the subject, give a complete characterisation of the material, in both intrinsic and doped forms, explain how to grow it for electronic applications, how to use the grown material, and a description of both passive and active devices in which it has been used with success. Diamond: Electronic Properties and Applications is a compendium of the available literature on the sub...

  1. Optical Properties and Boron Doping-Induced Conduction-Type Change in SnO2 Thin Films

    Science.gov (United States)

    Tran, Quang-Phu; Fang, Jau-Shiung; Chin, Tsung-Shune

    2016-01-01

    Boron-doped tin oxide (BTO) films, 0-5 at.% B, were prepared by sol-gel dip coating on a glass substrate. Dried precursor films were post-annealed at a temperature between 400°C and 750°C for 2 h. The obtained BTO thin films were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible light (UV-Vis) spectrometry, a four-point probe, and Hall-effect and Seebeck-effect measurements. Optimal optical transmittance was achieved for post-annealed BTO thin film at 700°C. XRD results show a rutile SnO2 structure with a preferred (110) orientation for all the films. The grain size is 47-21 nm, which reduces with increasing B contents. The optical transmittance is 84.6-88.5% at a wavelength of 550 nm and optical band gap of 3.52-3.75 eV. Electrical resistivity is (3.4-8.2) × 10-3 Ω cm, and figure of merit (0.9-4.3) × 10-3 Ω-1. Carrier concentration is (0.97-7.4) × 1020 cm-3 and mobility (2.5-7.8) cm2 V-1 s-1. BTO film with 4 at.% B shows an optimal combination of properties. Conduction type changes from n- (undoped) to p- (1-4 at.% B), then to n-types (5 at.% B), as evidenced from Hall-effect and Seebeck-effect measurements. This is explained by doping-generated defects and phase separations of Sn3O4 and B2O3.

  2. Metal-doped diamond-like carbon films synthesized by filter-arc deposition

    International Nuclear Information System (INIS)

    Diamond-like carbon (DLC) thin films are extensively utilized in the semiconductor, electric and cutting machine industries owing to their high hardness, high elastic modulus, low friction coefficients and high chemical stability. DLC films are prepared by ion beam-assisted deposition (BAD), sputter deposition, plasma-enhanced chemical vapor deposition (PECVD), cathodic arc evaporation (CAE), and filter arc deposition (FAD). The major drawbacks of these methods are the degraded hardness associated with the low sp3/sp2 bonding ratio, the rough surface and poor adhesion caused by the presence of particles. In this study, a self-developed filter arc deposition (FAD) system was employed to prepare metal-containing DLC films with a low particle density. The relationships between the DLC film properties, such as film structure, surface morphology and mechanical behavior, with variation of substrate bias and target current, are examined. Experimental results demonstrate that FAD-DLC films have a lower ratio, suggesting that FAD-DLC films have a greater sp3 bonding than the CAE-DLC films. FAD-DLC films also exhibit a low friction coefficient of 0.14 and half of the number of surface particles as in the CAE-DLC films. Introducing a CrN interfacial layer between the substrate and the DLC films enables the magnetic field strength of the filter to be controlled to improve the adhesion and effectively eliminate the contaminating particles. Accordingly, the FAD system improves the tribological properties of the DLC films

  3. Lithium decoration of three dimensional boron-doped graphene frameworks for high-capacity hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yunhui; Meng, Zhaoshun; Liu, Yuzhen; You, Dongsen; Wu, Kai; Lv, Jinchao; Wang, Xuezheng; Deng, Kaiming; Lu, Ruifeng, E-mail: dewei@ujs.edu.cn, E-mail: rflu@njust.edu.cn [Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094 (China); Rao, Dewei, E-mail: dewei@ujs.edu.cn, E-mail: rflu@njust.edu.cn [Institute for Advanced Materials, Jiangsu University, Zhenjiang 212013 (China)

    2015-02-09

    Based on density functional theory and the first principles molecular dynamics simulations, a three-dimensional B-doped graphene-interconnected framework has been constructed that shows good thermal stability even after metal loading. The average binding energy of adsorbed Li atoms on the proposed material (2.64 eV) is considerably larger than the cohesive energy per atom of bulk Li metal (1.60 eV). This value is ideal for atomically dispersed Li doping in experiments. From grand canonical Monte Carlo simulations, high hydrogen storage capacities of 5.9 wt% and 52.6 g/L in the Li-decorated material are attained at 298 K and 100 bars.

  4. Sintering of nano crystalline silicon carbide by doping with boron carbide

    Indian Academy of Sciences (India)

    M S Datta; A K Bandyopadhyay; B Chaudhuri

    2002-06-01

    Sinterable nano silicon carbide powders of mean particle size (37 nm) were prepared by attrition milling and chemical processing of an acheson type alpha silicon carbide having mean particle size of 0.39 m (390 nm). Pressureless sintering of these powders was achieved by addition of boron carbide of 0.5 wt% together with carbon of 1 wt% at 2050°C at vacuum (3 mbar) for 15 min. Nearly 99% sintered density was obtained. The mechanism of sintering was studied by scanning electron microscopy and transmission electron microscopy. This study shows that the mechanism is a solid-state sintering process. Polytype transformation from 6H to 4H was observed.

  5. Photovoltaic devices based on high density boron-doped single-walled carbon nanotube/n-Si heterojunctions

    International Nuclear Information System (INIS)

    A simple and easily processible photovoltaic device has been developed based on borondoped single-walled carbon nanotubes (B-SWNTs) and n-type silicon (n-Si) heterojunctions. The single-walled carbon nanotubes (SWNTs) were substitutionally doped with boron atoms by thermal annealing, in the presence of B2O3. The samples used for these studies were characterized by Raman spectroscopy, thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), and x-ray photoelectron spectroscopy (XPS). The fully functional solar cell devices were fabricated by airbrush deposition that generated uniform B-SWNT films on top of the n-Si substrates. The carbon nanotube films acted as exciton-generation sites, charge collection and transportation, while the heterojunctions formed between B-SWNTs and n-Si acted as charge dissociation centers. The current-voltage characteristics in the absence of light and under illumination, as well as optical transmittance spectrum are reported here. It should be noted that the device fabrication process can be made amenable to scalability by depositing direct and uniform films using airbrushing, inkjet printing, or spin-coating techniques

  6. Photocarrier Radiometry Investigation of Light-Induced Degradation of Boron-Doped Czochralski-Grown Silicon Without Surface Passivation

    Science.gov (United States)

    Wang, Qian; Li, Bincheng

    2016-04-01

    Light-induced degradation (LID) effects of boron-doped Cz silicon wafers without surface passivation are investigated in details by photocarrier radiometry (PCR). The resistivity of all samples is in the range of 0.006 Ω {\\cdot } {cm} to 38 Ω {\\cdot } {cm}. It is found that light-induced changes in surface state occupation have a great effect on LID under illumination. With the increasing contribution of light-induced changes in surface state occupation, the generation rate of the defect decreases. The light-induced changes in surface state occupation and light-induced degradation dominate the temporal behaviors of the excess carrier density of high- and low-resistivity Si wafers, respectively. Moreover, the temporal behaviors of PCR signals of these samples under laser illumination with different powers, energy of photons, and multiple illuminations were also analyzed to understand the light-induced change of material properties. Based on the nonlinear dependence of PCR signal on the excitation power, a theoretical model taking into account both light-induced changes in surface state occupation and LID processes was proposed to explain those temporal behaviors.

  7. Transport coefficients in diamond from ab-initio calculations

    Science.gov (United States)

    Löfâs, Henrik; Grigoriev, Anton; Isberg, Jan; Ahuja, Rajeev

    2013-03-01

    By combining the Boltzmann transport equation with ab-initio electronic structure calculations, we obtain transport coefficients for boron-doped diamond. We find the temperature dependence of the resistivity and the hall coefficients in good agreement with experimental measurements. Doping in the samples is treated via the rigid band approximation and scattering is treated in the relaxation time approximation. In contrast to previous results, the acoustic phonon scattering is the dominating scattering mechanism for the considered doping range. At room temperature, we find the thermopower, S, in the range 1-1.6 mV/K and the power factor, S2σ, in the range 0.004-0.16 μW /cm K2.

  8. A computational investigation of boron-doped chromium and chromium clusters by density functional theory

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The geometries,stabilities and electronic properties of Crn and CrnB(n=2-9) clusters have been systematically investigated by density functional theory.The results suggest that the lowest energy structures for CrnB clusters can be obtained by substituting one Cr atom in Crn+1 clusters with B atom.The geometries of CrnB clusters are similar to that of Crn+1 clusters except for local structural distortion.The second-order difference and fragmentation energy show Cr4,Cr6,Cr8,Cr3B,Cr5B and Cr8B cluster are the most stable among these studied clusters.The impurity B increases the stabilities of chromium cluster.When B is doped on the Crn clusters,cluster geometry does dominate positive role in enhancing their stability.The doped B atom does not change the coupling way of the Cr site in Crn clusters,but breaks the symmetry and the Cr atoms are no longer equivalent.The doped B atom increases the total magnetic moments of Crn in most cases.

  9. Preparation of Cubic Boron Nitride Coating on WC-Co Substrate by Micro/Nanocrystalline Diamond Film Interlayer%基于微纳米金刚石过渡层的cBN刀具涂层制备

    Institute of Scientific and Technical Information of China (English)

    徐锋; 左敦稳; 张旭辉; 户海峰; 张骋; 王珉

    2013-01-01

    Cubic Boron Nitride(cBN) is a super-hard material, of which hardness is only less than diamond. But it has excellent chemical stability, especially no chemical reaction with ferrous materials. The cBN coating has irreplaceable function in the application of modern cutting tools. Research is carried out on the preparation of cBN coating on YG6 by micro/nanocrystalline diamond (M/NCD) film inter-layer. The micro/nanocrystalline diamond film is deposited in hot filament chemical vapor deposition system and cBN is deposited in radio frequency magnetron sputtering system. The scanning electron microscopy (SEM), Raman, atomic force microscopy(AFM), Fourier transferred infrared(FTIR) and in-denter are used to investigate the content, morphology and adhesion of the coating. The results show that the adhesion of cBN coating on WC-Co by micro/nanocrystalline diamond interlayer is much higher than that by nano diamond interlayer. The moderate bias voltage is important for the cBN film deposition in the magnetron sputtering process.%立方氮化硼(Cubic Boron Nitride,cBN)是仅次于金刚石的超硬材料,比金刚石具有更高的化学稳定性,可以胜任铁系金属的加工.本文在YG6硬质合金上基于微纳米金刚石过渡层开展cBN涂层的制备研究.本文在热丝化学气相沉积系统中制备微纳米金刚石过渡层(Micro/nanocrystalline diamond,M/NCD),在射频磁控溅射系统中制备cBN涂层,并对M/NCD与cBN涂层进行了成分、微观形貌与结合性能的研究.研究结果发现,在硬质合金基体上,M/NCD过渡层的结合性能明显优于NCD过渡层.磁控溅射制备cBN涂层过程中,存在适合cBN沉积的衬底偏压阈值,过高或过低的衬底偏压均不利于cBN含量的提高.

  10. Adsorptive Separation and Sequestration of Krypton, I and C14 on Diamond Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Tushar [Univ. of Missouri, Columbia, MO (United States); Loyalka, Sudarsha [Univ. of Missouri, Columbia, MO (United States); Prelas, Mark [Univ. of Missouri, Columbia, MO (United States); Viswanath, Dabir [Univ. of Missouri, Columbia, MO (United States)

    2015-03-31

    The objective of this research proposal was to address the separation and sequestration of Kr and I from each other using nano-sized diamond particles and retaining these in diamond until they decay to the background level or can be used as a byproduct. Following removal of Kr and I, an adsorbent will be used to adsorb and store CO2 from the CO2 rich stream. A Field Enhanced Diffusion with Optical Activation (FEDOA-a large scale process that takes advantage of thermal, electrical, and optical activation to enhance the diffusion of an element into diamond structure) was used to load Kr and I on micron or nano sized particles having a larger relative surface area. The diamond particles can be further increased by doping it with boron followed by irradiation in a neutron flux. Previous studies showed that the hydrogen storage capacity could be increased significantly by using boron-doped irradiated diamond particles. Diamond powders were irradiated for a longer time by placing them in a quartz tube. The surface area was measured using a Quantachrome Autosorb system. No significant increase in the surface area was observed. Total surface area was about 1.7 m2/g. This suggests the existence of very minimal pores. Interestingly it showed hysteresis upon desorption. A reason for this may be strong interaction between the surface and the nitrogen molecules. Adsorption runs at higher temperatures did not show any adsorption of krypton on diamond. Use of a GC with HID detector to determine the adsorption capacity from the breakthrough curves was attempted, but experimental difficulties were encountered.

  11. A deep-submicron single gate CMOS technology using in-situ boron-doped polycrystalline silicon-germanium gates formed by rapid thermal chemical vapor deposition

    Science.gov (United States)

    Li, Vivian Zhi-Qi

    This thesis presents a comprehensive study of in-situ boron doped polycrystalline-Sisb{1-x}Gesb{x} films deposited in a rapid thermal chemical vapor deposition system and used as the gate electrode in the deep submicron bulk CMOS technology. This work includes an investigation of the nucleation behavior of poly-Sisb{1-x}Gesb{x} films on the oxide surface, development of a deposition process using Sisb2Hsb6,\\ GeHsb4 and Bsb2Hsb6 gases in addition to using common gas mixture of SiHsb4,\\ GeHsb4 and Bsb2Hsb6 in a RTCVD system, characterization of the deposited film structure and its properties, examination of the electrical properties, extraction of the workfunction as a function of the Ge content in the film, development of the NMOS, PMOS and CMOS processes for in-situ boron doped poly-Sisb{1-x}Gesb{x} gate technology, assessment of the impact of poly-Sisb{1-x}Gesb{x} gate on the device performance through computer simulations. The process integration issues such as boron penetration, poly-depletion and gate oxide reliability, and characterization of deep submicron CMOS devices are also studied. One critical concern with the use of poly-Sisb{1-x}Gesb{x} gate materials is its partially selective deposition process on the SiOsb2. In this work, we demonstrated non-selective deposition processes for poly-Sisb{1-x}Gesb{x} without conventional Si pre-deposition onto oxide. One approach is by using in-situ boron doping method and another is by using Sisb2Hsb6 as the Si source gas. Also, it was found that the density of the nucleation sites at the initial stage of deposition increases with the increase of the Bsb2Hsb6 gas flow rate. The resulting continuous poly-Sisb{1-x}Gesb{x} films were attributed to the preferential adsorption of boron atoms onto the oxide surface providing the necessary nucleation sites for the subsequent Sisb{1-x}Gesb{x} film growth. For undoped poly-Sisb{1-x}Gesb{x} films, continuous films can be formed on the oxide using Sisb2Hsb6 and GeHsb4 gases

  12. Organic Solar Cells with Boron- or Nitrogen-Doped Carbon Nanotubes in the P3HT : PCBM Photoactive Layer

    Directory of Open Access Journals (Sweden)

    Godfrey Keru

    2016-01-01

    Full Text Available Either boron- or nitrogen-doped carbon nanotubes (B- or N-CNTs were incorporated in bulk heterojunction organic solar cells photoactive layer composed of poly(3-hexylthiophene (P3HT : (6,6-phenyl-C61-butyric acid methyl ester (PCBM. The physical and chemical properties were investigated using different spectroscopic techniques. The cell performance was followed from their current-voltage (J-V characteristics. Recombination dynamics of the photo-generated free charge carriers were investigated using micro- to milliseconds transient absorption spectroscopy (TAS. Transmission electron microscopy (TEM images revealed the presence of cone structures and bamboo compartments in B-CNTs and N-CNTs, respectively. X-ray photoelectron spectroscopy (XPS revealed very little boron was substituted in the carbon network and presence of pyrrolic, pyridinic, and quaternary species of nitrogen in N-CNTs. J-V characteristics were found to be similar for the devices with B- and N-CNTs even though boron- and nitrogen-doped CNTs are known to have different properties, that is, p-type and n-type, respectively. TAS results showed that all devices had long lived free charge carriers but the devices with B- or N-CNTs had low power conservation efficiency and voltage.

  13. Potentiometric application of boron- and phosphorus-doped glassy carbon electrodes

    Directory of Open Access Journals (Sweden)

    ZORAN V. LAUSEVIC

    2001-03-01

    Full Text Available Acomparative study was carried out of the potentiometric application of boronand phosphorus-doped and undoped glassy carbon samples prepared at the same heat treatment temperature (HTT 1000°C. The electrochemical activities of the obtained electrode materials were investigated on the example of argentometric titrations. It was found that the electrochemical behaviour of the doped glassy carbon samples are very similar to a Sigri (undoped glassy carbon sample (HTT 2400°C. The experiments showed that the potentiometric response depends on the polarization mode, the nature of the sample, the pretreatment of the electrode surface, and the nature of the supporting electrolyte. The amounts of iodide, bromide, and of chloridewere determined to be 1.27 mg, 0.80 mg and 0.54 mg, respectively, with a maximum relative standard deviation of less than 1.1%. The obtained results are in good agreement with the results of comparative potentiometric titrations using a silver indicator electrode. The titrationmethod was applied to the indirect determination of pyridoxine hydrochloride, i.e., vitamin B6.

  14. Tensile properties of a boron/nitrogen-doped carbon nanotube–graphene hybrid structure

    Directory of Open Access Journals (Sweden)

    Kang Xia

    2014-03-01

    Full Text Available Doping is an effective approach that allows for the intrinsic modification of the electrical and chemical properties of nanomaterials. Recently, a graphene and carbon nanotube hybrid structure (GNHS has been reported, which extends the excellent properties of carbon-based materials to three dimensions. In this paper, we carried out a first-time investigation on the tensile properties of the hybrid structures with different dopants. It is found that with the presence of dopants, the hybrid structures usually exhibit lower yield strength, Young’s modulus, and earlier yielding compared to that of a pristine hybrid structure. For dopant concentrations below 2.5% no significant reduction of Young’s modulus or yield strength could be observed. For all considered samples, the failure is found to initiate at the region where the nanotubes and graphene sheets are connected. After failure, monatomic chains are normally observed around the failure region. Dangling graphene layers without the separation of a residual CNT wall are found to adhere to each other after failure with a distance of about 3.4 Å. This study provides a fundamental understanding of the tensile properties of the doped graphene–nanotube hybrid structures, which will benefit the design and also the applications of graphene-based hybrid materials.

  15. Characterisation of irradiation damage and dopant distribution in synthetic diamonds by luminescence micro-spectroscopy

    CERN Document Server

    Charles, S J

    2002-01-01

    ground and two excited states. The lower energy excited state has a slow rate of decay and the second, higher energy excited state, which is thermally populated, has a high rate of decay to the ground state. The higher energy excited state has a spectrum with a local mode and the centre is metastably enhanced by exposure to UV light. DBI is not dependent on the isotope of boron used to elope the diamonds. The lines at 650.2 nm and 667.8 nm also come from the same centre as each other, designated DB2. The CVD B-doped diamond samples showed changes in boron level by approximately an order of magnitude on scales smaller than 5 mu m. These differences in boron level are due to different surface facet orientations of the grains that comprise the sample, and different facets have different rates of uptake of boron during growth. A simple, qualitative, way of showing the differences in boron level has been shown by using cathodoluminescence (CL) topography, which agrees with results from UV CL spectroscopy. Raman sp...

  16. H-terminated polycrystalline boron doped diamond electrode for geochemical sensing into underground components of nuclear repositories

    OpenAIRE

    Boussadi, A.; Betelu, Stéphanie; Silva, F.; Ignatiadis, Ioannis

    2012-01-01

    Nuclear waste repositories are being installed in deep excavated rock formations in some places in Europe to isolate and store radioactive waste. In France, Callovo-Oxfordian formation (COx) is potential candidate for nuclear waste repository. It is thus necessary to measure in situ the state of a structure's health during its entire life. The monitoring of the near-field rock and the knowledge of the geochemical transformations can be carried out by a set of sensors for a sustainable managem...

  17. Metal/Diamond Composite Thin-Film Electrodes: New Carbon Supported Catalytic Electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Greg M. Swain, PI

    2009-03-10

    The DOE-funded research conducted by the Swain group was focused on (i) understanding structure-function relationships at boron-doped diamond thin-film electrodes, (ii) understanding metal phase formation on diamond thin films and developing electrochemical approaches for producing highly dispersed electrocatalyst particles (e.g., Pt) of small nominal particle size, (iii) studying the electrochemical activity of the electrocatalytic electrodes for hydrogen oxidation and oxygen reduction and (iv) conducting the initial synthesis of high surface area diamond powders and evaluating their electrical and electrochemical properties when mixed with a Teflon binder. (Note: All potentials are reported versus Ag/AgCl (sat'd KCl) and cm{sup 2} refers to the electrode geometric area, unless otherwise stated).

  18. SINTERING MECHANISM OF PURE AND CARBON_DOPED BORON CARBIDE%纯B4C和掺碳B4C的烧结机制

    Institute of Scientific and Technical Information of China (English)

    尹邦跃; 王零森; 方寅初

    2001-01-01

    Sintering densificaton process of pure and carbon_doped boron carbide powders with 0.42 μm median particle size were studied. Their sintering kinetic equations were obtained according to the influence of sintering temperature and holding time on linear shrinkage rate. The sintering mechanisms were investigated by comparing the characteristic exponent n. It is deduced that the main sintering mechanisms shill be volume diffusion and grain boundary diffusion for pure boron carbide and grain boundary diffusion for carbon_doped boron carbide showing activated sintering. The relative density of the carbon_doped B4C sintered at 2 160 ℃ for 45 min is more than 90%. Apart from those dissolved in the sintered boron carbide, the rest of the added carbon is in the form of free carbon, no new phase formed. Carbon_doping also result in a great decrease of B4C grain size.%研究了中位粒径为0.42 μm的纯B4C和掺碳B4C粉末的烧结致密化过程. 根据烧结温度和保温时间对线收缩率的影响,得出了它们的烧结动力学方程;由特征指数n值对比研究了它们的烧结致密化机制. 纯B4C的烧结致密化机制为体扩散和晶界扩散,而掺碳B4C的烧结机制主要为晶界扩散,因此,掺碳对B4C起到了活化烧结的作用. 在2 160 ℃烧结45 min,掺碳B4C烧结后相对密度大于90%. 掺入的碳除了固溶于B4C晶格中之外,其它均以游离石墨形式存在,不形成新相. 掺碳还导致B4C晶粒尺寸大大减小.

  19. Reactivity of boron- and nitrogen-doped carbon nanotubes functionalized by (Pt, Eu) atoms toward O2 and CO: A density functional study

    Science.gov (United States)

    Abdel Aal, S.

    2016-01-01

    The adsorption behavior and electronic properties of CO and O2 molecules at the supported Pt and Eu atoms on (5,5) armchair SWCNT have been systematically investigated within density functional theory (DFT). Fundamental aspects such as adsorption energy, natural bond orbital (NBO), charge transfer, frontier orbitals and the projected density of states (PDOS) are elucidated to analyze the adsorption properties of CO and O2 molecules. The results reveal that B- and N-doping CNTs can enhance the binding strength and catalytic activity of Pt (Eu) anchored on the doped-CNT, where boron-doping is more effective. The electronic structures of supported metal are strongly influenced by the presence of gases. After adsorption of CO and O2, the changes in binding energy, charge transfer and conductance may lead to the different response in the metal-doped CNT-based sensors. It is expected that these results could provide helpful information for the design and fabrication of the CO and O2 sensing devices. The high catalytic activity of Pt supported at doped-CNT toward the interaction with CO and O2 may be attributed to the electronic resonance particularly among Pt-5d, CO-2π* and O2-2π* antibonding orbitals. In contrast to the supported Eu at doped-CNT, the Eu atom becomes more positively charged, which leads to weaken the CO adsorption and promote the O2 adsorption, consequently enhancing the activity for CO oxidation and alleviating the CO poisoning of the europium catalysts. A notable orbital hybridization and electrostatic interaction between these two species in adsorption process being an evidence of strong interaction. The electronic structure of O2 adsorbed on Eu-doped CNT resembles that of O2-, therefore the transferred charge weakens the O-O bonds and facilitates the dissociation process, which is the precondition for the oxygen reduction reaction (ORR).

  20. Humid environment stability of low pressure chemical vapor deposited boron doped zinc oxide used as transparent electrodes in thin film silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Steinhauser, Jerome, E-mail: jerome.steinhauser@oerlikon.com [Institute of Microtechnology (IMT), University of Neuchatel, CH-2000 Neuchatel (Switzerland); Meyer, Stefan; Schwab, Marlene; Fay, Sylvie; Ballif, Christophe [Institute of Microtechnology (IMT), University of Neuchatel, CH-2000 Neuchatel (Switzerland); Kroll, U.; Borrello, D. [Oerlikon Solar-Lab, 2000 Neuchatel (Switzerland)

    2011-10-31

    The stability in humid environment of low pressure chemical vapor deposited boron doped zinc oxide (LPCVD ZnO:B) used as transparent conductive oxide in thin film silicon solar cells is investigated. Damp heat treatment (exposure to humid and hot atmosphere) induces a degradation of the electrical properties of unprotected LPCVD ZnO:B layers. By combining analyses of the electrical and optical properties of the films, we are able to attribute this behavior to an increase of electron grain boundary scattering. This is in contrast to the intragrain scattering mechanisms, which are not affected by damp heat exposure. The ZnO stability is enhanced for heavily doped films due to easier tunneling through potential barrier at grain boundaries.