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Sample records for boron-doped diamonds based

  1. 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.

  2. Lab-made Sensors Based on Boron-doped Diamond for Determination of Herbicide Linuron

    Czech Academy of Sciences Publication Activity Database

    Štěpánková, M.; Šelešovská, R.; Janíková, L.; Vojs, M.; Marton, M.; Behúl, M.; Nováková, Kateřina; Chýlková, J.

    Ústí nad Labem: Srsenová Lenka - Best Servis, 2015 - (Navrátil, T.; Fojta, M.; Schwarzová, K.), s. 236-240 ISBN 978-80-905221-3-8. [Moderní elektrochemické metody /35./. Jetřichovice (CZ), 18.05.2015-22.05.2015] Institutional support: RVO:61388955 Keywords : Boron doped diamond electrode * sensors * voltammetry Subject RIV: CG - Electrochemistry

  3. 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

  4. Toward a Boron-Doped Ultrananocrystalline Diamond Electrode-Based Dielectrophoretic Preconcentrator.

    Science.gov (United States)

    Zhang, Wenli; Radadia, Adarsh D

    2016-03-01

    This paper presents results on immunobeads-based isolation of rare bacteria and their capture at a boron-doped ultrananocrystalline diamond (BD-UNCD) electrode in a microfluidic dielectrophoretic preconcentrator. We systematically vary the bead surface chemistry and the BD-UNCD surface chemistry and apply dielectrophoresis to improve the specific and the nonspecific capture of bacteria or beads. Immunobeads were synthesized by conjugating antibodies to epoxy-/sulfate, aldehyde-/sulfate, or carboxylate-modified beads with or without poly(ethylene glycol) (PEG) coimmobilization. The carboxylate-modified beads with PEG provided the highest capture efficiency (∼65%) and selectivity (∼95%) in isolating live Escherichia coli O157:H7 from cultures containing 1000 E. coli O157:H7 colony-forming units (cfu)/mL, or ∼500 E. coli O157:H7 and ∼500 E. coli K12 cfu/mL. Higher specificity was achieved with the addition of PEG to the antibody-functionalized bead surface, highest with epoxy-/sulfate beads (85-86%), followed by carboxylate-modified beads (76-78%) and aldehyde-/sulfate beads (74-76%). The bare BD-UNCD electrodes of the preconcentrator successfully withstood 240 kV/m for 100 min that was required for the microfluidic dielectrophoresis of 1 mL of sample. As expected, the application of dielectrophoresis increased the specific and the nonspecific capture of immunobeads at the BD-UNCD electrodes; however, the capture specificity remained unaltered. The addition of PEG to the antibody-functionalized BD-UNCD surface had little effect on the specificity in immunobeads capture. These results warrant the fabrication of electrical biosensors with BD-UNCD so that dielectrophoretic preconcentration can be performed directly at the biosensing electrodes. PMID:26829879

  5. 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

  6. Fabrication and characterization of boron-doped nanocrystalline diamond-coated MEMS probes

    Science.gov (United States)

    Bogdanowicz, Robert; Sobaszek, Michał; Ficek, Mateusz; Kopiec, Daniel; Moczała, Magdalena; Orłowska, Karolina; Sawczak, Mirosław; Gotszalk, Teodor

    2016-04-01

    Fabrication processes of thin boron-doped nanocrystalline diamond (B-NCD) films on silicon-based micro- and nano-electromechanical structures have been investigated. B-NCD films were deposited using microwave plasma assisted chemical vapour deposition method. The variation in B-NCD morphology, structure and optical parameters was particularly investigated. The use of truncated cone-shaped substrate holder enabled to grow thin fully encapsulated nanocrystalline diamond film with a thickness of approx. 60 nm and RMS roughness of 17 nm. Raman spectra present the typical boron-doped nanocrystalline diamond line recorded at 1148 cm-1. Moreover, the change in mechanical parameters of silicon cantilevers over-coated with boron-doped diamond films was investigated with laser vibrometer. The increase of resonance to frequency of over-coated cantilever is attributed to the change in spring constant caused by B-NCD coating. Topography and electrical parameters of boron-doped diamond films were investigated by tapping mode AFM and electrical mode of AFM-Kelvin probe force microscopy (KPFM). The crystallite-grain size was recorded at 153 and 238 nm for boron-doped film and undoped, respectively. Based on the contact potential difference data from the KPFM measurements, the work function of diamond layers was estimated. For the undoped diamond films, average CPD of 650 mV and for boron-doped layer 155 mV were achieved. Based on CPD values, the values of work functions were calculated as 4.65 and 5.15 eV for doped and undoped diamond film, respectively. Boron doping increases the carrier density and the conductivity of the material and, consequently, the Fermi level.

  7. 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.

  8. 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.

  9. Intrinsic and boron-doped diamond microstructured for electrochemical batteries

    Czech Academy of Sciences Publication Activity Database

    Kromka, Alexander; Babchenko, Oleg; Rezek, Bohuslav; Ižák, Tibor; Libertínová, Jitka; Hruška, Karel; Nyholm, L.; de Oliviera Jorge, E.

    Prague : Institute of Physics ASCR, 2012 - (Rezek, B.; Kromka, A.), s. 43-44 ISBN 978-80-260-1593-2. [International Workshop on Diamond Nanotechnology and Science Progress. Prague (CZ), 15.06.2011-17.06.2011] Institutional research plan: CEZ:AV0Z10100521 Keywords : nanocrystalline diamond * intrinsic diamond * boron-doped diamond * surface conductivity * SEM * AFM Subject RIV: BM - Solid Matter Physics ; Magnetism

  10. 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...

  11. 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.

  12. 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.

  13. 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.

  14. Structured boron doped diamond electrodes for determination of dopamine

    Czech Academy of Sciences Publication Activity Database

    Vojs, Marian; Behúl, M.; Michniak, P.; Řeháček, V.; Marton, M.; Veselý, M.; Kromka, Alexander

    Žilina: University of Žilina, 2013 - (Pudiš, D.; Lettrichová, I.; Šušlik, Ĺ.; Kováč jr., J.; Vincze, A.), s. 135-139 ISBN 978-80-554-0689-3. [International Conference on Advances in Electronic and Photonic Technologies. Nový Smokovec (SK), 02.06.2013-05.06.2013] Institutional support: RVO:68378271 Keywords : boron-doped diamond (BDD) * dopamine * nano -structuring Subject RIV: BM - Solid Matter Physics ; Magnetism

  15. 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}.

  16. 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

  17. 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.

  18. 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.

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

    Science.gov (United States)

    Zubkov, V. I.; Kucherova, O. V.; Bogdanov, S. A.; Zubkova, A. V.; Butler, J. E.; Ilyin, V. A.; Afanas'ev, A. V.; Vikharev, A. L.

    2015-10-01

    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 × 10-13 down to 2 × 10-17 cm2 was noticed. Moreover, for the hopping conduction the capture cross section becomes 4 orders of magnitude less (˜2 × 10-20 cm2). At T > Troom 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.

  20. 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

  1. 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

  2. In/extrinsic granularity in superconducting boron-doped diamond

    International Nuclear Information System (INIS)

    When charge carriers are introduced in diamond, e.g. by chemical doping with Boron (B), the C1-xBx diamond:B can exhibit an insulator-to-metal transition (pMott∼2x1020cm-3). Under even heavier boron doping (nB∼1021cm-3), diamond becomes superconducting. Using microwave plasma-assisted chemical vapor deposition (MPCVD) we have prepared diamond:B thin films with critical offset temperatures TC below 3 K. We have investigated the transport properties of these diamond:B thin films, which show pronounced granular effects. It turns out, that this granularity is both intrinsic as well as extrinsic. The extrinsic granularity is the effect of the growth method which needs to start from a seeding of the substrate with detonation nanodiamond, which acts as nucleation centers for further MPCVD growth of the film. In using SPM/STM techniques, we also observed intrinsic granularity, meaning that within physical grains, we observe also a strong intragrain modulation of the order parameter. As a consequence of these granularities, the transport properties show evidence of (i) strong superconducting fluctuations and (ii) Cooper pair tunneling and/or quasiparticle tunneling. The latter effects explain the observed negative magnetoresistance.

  3. Model for the boron-doping dependence of the critical temperature of superconducting boron-doped diamond

    Czech Academy of Sciences Publication Activity Database

    Šopík, Břetislav

    2009-01-01

    Roč. 11, č. 10 (2009), 103026/1-103026/10. ISSN 1367-2630 R&D Projects: GA AV ČR IAA100100712 Grant ostatní: GAČR(CZ) GA202/07/0597 Institutional research plan: CEZ:AV0Z10100521 Keywords : superconductivity * boron-doped diamond Subject RIV: BE - Theoretical Physics Impact factor: 3.312, year: 2009

  4. 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...

  5. Electrochemical growth of polypyrrole on boron doped diamond with various surface termination

    Czech Academy of Sciences Publication Activity Database

    Ukraintsev, Egor; Kromka, Alexander; Janssen, W.; Haenen, K.; Rezek, Bohuslav

    Hasselt : SBDD XVIII, 2013. s. 100-100. [Hasselt Diamond Workshop 2013 - SBDD XVIII. 27.02.2013 - 01.03. 2013, Hasselt] Institutional support: RVO:68378271 Keywords : boron doped diamond * hydrogen terminated diamond * oxygen terminated diamond * polypyrrole * AFM Subject RIV: BM - Solid Matter Physics ; Magnetism

  6. 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.

  7. Understanding Persulfate Production at Boron Doped Diamond Film Anodes

    International Nuclear Information System (INIS)

    This research used molecular modeling and rotating disk electrode experiments (RDE) to investigate possible reaction pathways for persulfate production via electrolysis of sulfuric acid solutions using boron doped diamond (BDD) film anodes. Density functional theory (DFT) modeling indicated that uncatalyzed oxidation of SO42− and HSO4− occurs at lower potentials than water oxidation, and that sulfate radical species (SO4−• and HSO4• ) may be produced via direct electron transfer, or via reaction with hydroxyl radicals. The RDE experiments indicated that rates of persulfate generation were strongly dependent of the condition of the electrode surface, and that aged electrode surfaces favored water oxidation over direct SO42− and HSO4− oxidation. Combination of sulfate radical species in solution is the lowest energy pathway for persulfate production. Sulfate radical species may also react with radical sites on the electrode surface and produce chemisorbed intermediates that can stabilize sulfate radical species. Reaction of the chemisorbed intermediates with a bisulfate radical can produce persulfate via a surface catalyzed pathway. However, the activation barriers for this pathway are much higher than those for persulfate production via solution phase species

  8. 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...

  9. 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

  10. 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

  11. Focused ion beam (FIB)-induced changes in the electrochemical behavior of boron-doped diamond (BDD) electrodes

    International Nuclear Information System (INIS)

    Micro- and nanostructured electrodes play a significant role in modern electroanalytical chemistry. Here, we report on the effect of focused ion beam-induced changes in the surface layers of nanocrystalline highly boron-doped diamond (BDD). The impact of gallium ions induces an amorphization of the surface layers of the BDD lattice, and hence, changes the electron transfer behavior of redox species, which electron transfer is sensitive to surface properties. These changes in heterogeneous electron transfer behavior are investigated in dependence of FIB patterning parameters. The effects of electrochemical post-milling treatments were studied for restoring the electrochemical properties. In addition, Raman spectroscopic and electron backscatter diffraction (EBSD) measurements revealed that amorphous carbon is largely removed during the post-milling electrochemical treatment at very negative potentials. Hence, FIB-based nanostructuring of BDD-electrodes with an optimized post fabrication treatment enables the fabrication of miniaturized devices based on boron-doped diamond for a wide variety of electroanalytical applications

  12. Electrochemical impedance spectroscopy of polycrystalline boron doped diamond layers with hydrogen and oxygen terminated surface

    Czech Academy of Sciences Publication Activity Database

    Vlčková Živcová, Zuzana; Petrák, Václav; Frank, Otakar; Kavan, Ladislav

    2015-01-01

    Roč. 55, MAY 2015 (2015), s. 70-76. ISSN 0925-9635 R&D Projects: GA ČR GA13-31783S Institutional support: RVO:61388955 ; RVO:68378271 Keywords : Boron doped diamond * Electrochemical impedance spectroscopy * Aqueous electrolyte solution Subject RIV: CG - Electrochemistry Impact factor: 1.919, year: 2014

  13. A hydrophobic three-dimensionally networked boron-doped diamond electrode towards electrochemical oxidation.

    Science.gov (United States)

    He, Yapeng; Lin, Haibo; Wang, Xue; Huang, Weimin; Chen, Rongling; Li, Hongdong

    2016-06-28

    A boron-doped diamond electrode with a three-dimensional network was fabricated on a mesh titanium substrate. Properties such as higher surface area, enhanced mass transfer and a hydrophobic surface endowed the prepared electrode with excellent electrochemical oxidation ability towards contaminants. PMID:27264247

  14. NANOCRYSTALLINE BORON-DOPED DIAMOND: ELECTROCHEMICAL AND INSITU RAMAN SPECTROELECTROCHEMICAL CHARACTERIZATION

    Czech Academy of Sciences Publication Activity Database

    Vlčková Živcová, Zuzana; Frank, Otakar; Petrák, Václav; Tarábková, Hana; Bouša, Milan; Nesládek, M.; Kavan, Ladislav

    Cancún: European Materials Research Society, 2011. S17-16. [International Materials Research Congress IMRC /20./. 13.08.2011-19.08.2011, Cancún] Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z10100520 Keywords : nanocrystalline boron-doped diamond * electrochemistry Subject RIV: CG - Electrochemistry

  15. Spectral Sensitization of Nanocrystalline Boron-Doped Diamond Electrode for Application in Photoelectrochemical Solar Cells

    Czech Academy of Sciences Publication Activity Database

    Kavan, Ladislav; Vlčková Živcová, Zuzana; Krýsová, Hana; Petrák, Václav; Bartoň, Jan; Cígler, Petr; Nesládek, M.

    San Francisco: Material Research Society, 2015. [2015 MRS Spring Meeting & Exhibit. Program: Symposium R—Photoactive Nanoparticles and Nanostructures. 06.04.2015-10.04.2015, San Francisco] R&D Projects: GA ČR GA13-31783S Institutional support: RVO:68378271 ; RVO:61388955 ; RVO:61388963 Keywords : nanocrystalline boron doped diamond * electrochemistry * photoelectrochemistry Subject RIV: CG - Electrochemistry

  16. Nanocrystalline Boron-doped Diamond: Spectro /Photo/ Electrochemical Properties and Prospective Applications in Solar Cells

    Czech Academy of Sciences Publication Activity Database

    Kavan, Ladislav; Vlčková Živcová, Zuzana; Krýsová, Hana; Petrák, Václav; Janda, Pavel; Tarábková, Hana; Nesládek, Miloš

    Barcelona: Phantoms Foundation, 2014. s. 106-106. [Trends in Nanotechnology 2014. 27.10.2014-31.10.2014, Barcelona] R&D Projects: GA ČR GA13-31783S Institutional support: RVO:61388955 ; RVO:68378271 Keywords : nanocrystalline boron-doped diamond * electrochemistry * dye-sensitized solar cell Subject RIV: CG - Electrochemistry

  17. Visible-light sensitization of boron-doped nanocrystalline diamond through non-covalent surface modification

    Czech Academy of Sciences Publication Activity Database

    Krýsová, Hana; Vlčková Živcová, Zuzana; Bartoň, Jan; Petrák, Václav; Nesladek, M.; Cígler, Petr; Kavan, Ladislav

    2015-01-01

    Roč. 17, č. 2 (2015), s. 1165-1172. ISSN 1463-9076 R&D Projects: GA ČR GA13-31783S Institutional support: RVO:61388955 ; RVO:61388963 ; RVO:68378271 Keywords : nanocrystallines * visible-light sensitization * boron-doped diamond Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.493, year: 2014

  18. 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

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

    OpenAIRE

    Alegre, Maria De La Paz; Araújo, Daniel; Fiori, Alexandre; Pinero, Jose Carlos; Lloret, Fernando; Villar, Maria Del Pilar; Achatz, Philippe; Chicot, Gauthier; Bustarret, Etienne; F. Jomard

    2014-01-01

    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 CH4 /H2 molar ratios and on growth directions. The critical boron concentration lied in the 6.5–17.0 X 10 20 at/cm3 range in the direction and at 3.2 X 1021 at/cm 3 for the one. Strain related effects induced by the doping are shown not to be respon...

  20. Electrochemical oxidation route of methyl paraben on a boron-doped diamond anode

    International Nuclear Information System (INIS)

    Parabens have been widely used in different industries and can be found in health and personal care products. They are esters of p-hydroxy-benzoic acid associated with breast tumors and classified as endocrine disruptors. This study describes the galvanostatic electrochemical oxidation of methyl paraben (MePa) on a boron-doped diamond anode using current densities in the 1.35 to 21.6 mA cm−2 range. The degradation process can be controlled by either charge transfer or mass transport, according to the experimental conditions and rate of mineralization of MePa increased by the current density. The concentration variation as a function of electrolysis time showed that the degradation kinetics follows a pseudo first-order law. A mechanism for the MePa degradation based on reactive intermediates determined by gas chromatography mass spectrometry (GC-MS) is also proposed

  1. 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...

  2. 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.

  3. 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...

  4. 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 ...

  5. 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 ...

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

    OpenAIRE

    Alejandro Medel; Erika Bustos; Karen Esquivel; Luis A. Godínez; Yunny Meas

    2012-01-01

    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. ...

  7. 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...

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

    Czech Academy of Sciences Publication Activity Database

    Mortet, Vincent; Pernot, J.; Jomard, F.; Soltani, A.; Remeš, Zdeněk; Barjon, J.; D´Haen, J.; Haenen, K.

    2015-01-01

    Roč. 35, Mar (2015), s. 29-34. ISSN 0925-9635 R&D Projects: GA ČR GA13-31783S Grant ostatní: EU(XE) CZ.1.07/2.3.00/20.0306 Institutional support: RVO:68378271 Keywords : diamond * boron * doping * crystalline orientation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.919, year: 2014

  9. Fabrication and characterization of n-type zinc oxide/p-type boron doped diamond heterojunction

    Czech Academy of Sciences Publication Activity Database

    Marton, M.; Mikolášek, M.; Bruncko, J.; Novotný, I.; Ižák, Tibor; Vojs, M.; Kozak, Halyna; Varga, Marián; Artemenko, Anna; Kromka, Alexander

    2015-01-01

    Roč. 66, č. 5 (2015), s. 277-281. ISSN 1335-3632 R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk(CZ) 7AMB14SK024 Institutional support: RVO:68378271 Keywords : boron doped diamond * zinc oxide * Raman spectroscopy * bipolar heterostructure * wide-bandgap Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.378, year: 2014

  10. 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.

  11. The Immunosuppressive drug – Rapamycin – Electroanalytical Sensing Using Boron- Doped Diamond electrode

    International Nuclear Information System (INIS)

    Graphical abstract: Display Omitted -- Abstract: This paper presents for the first time the study of electrochemical behavior of well known immunosuppressant drug – rapamycin (sirolimus) using boron-doped diamond electrode. Rapamycin provided single and oval-shaped oxidation peak at +1.1 V vs. Ag/AgCl electrode in Britton–Robinson buffer solution at pH 3 confirming highly irreversible behavior of analyte at boron-doped diamond electrode. A differential pulse voltammetry was used for quantification of tested drug under the optimum experimental conditions. The calibration curve was linear over the range from 0.5 to 19.5 μM (R2 = 0.9976) with detection limit of 0.22 μM. Repeatability of ten successfully measurements of three different concentrations (5, 10 and 15 μM) was 2.5, 1.9 and 1,7 %, respectively. Influence of most common biomolecules presented in urine samples was evaluated. The suggested analytical methodology was successfully applied for determination of rapamycin in four urine samples with excellent recoveries. The developed approach could be beneficial in analysis of rapamycin in biological samples using boron-doped diamond electrode as up-to-date electrochemical sensor and could represent inexpensive analytical alternative to separation methods

  12. 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)

  13. Electrical conductivity enhancement by boron-doping in diamond using first principle calculations

    International Nuclear Information System (INIS)

    Graphical abstract: Representation of the electrical charge distributions of boron-doped diamond. - Highlights: • DFT calculations of boron doping in diamond films using VASP codes. • Electron charge distributions using TDOS/PDOS for B-doped diamond. • B–C bond populations and bond lengths determined to verify structure. • Creation of impurity states in band gap region enhances conductivity. • DFT calculations verify our experimental results for B-doped diamond. - Abstract: Boron doping in diamond plays a vital role in enhancing electrical conductivity of diamond by making it a semiconductor, a conductor or even a superconductor. To elucidate this fact, partial and total density of states has been determined as a function of B-content in diamond. Moreover, the orbital charge distributions, B–C bond lengths and their population have been studied for B-doping in pristine diamond thin films by applying density functional theory (DFT). These parameters have been found to be influenced by the addition of different percentages of boron atoms in diamond. The electronic density of states, B–C bond situations as well as variations in electrical conductivities of diamond films with different boron content and determination of some relationship between these parameters were the basic tasks of this study. Diamond with high boron concentration (∼5.88% B-atoms) showed maximum splitting of energy bands (caused by acceptor impurity states) at the Fermi level which resulted in the enhancement of electron/ion conductivities. Because B atoms either substitute carbon atoms and/or assemble at grain boundaries (interstitial sites) inducing impurity levels close to the top of the valence band. At very high B-concentration, impurity states combine to form an impurity band which accesses the top of the valence band yielding metal like conductivity. Moreover, bond length and charge distributions are found to decrease with increase in boron percentage in diamond. It is

  14. 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.

  15. Laser-excited photoemission spectroscopy study of superconducting boron-doped diamond

    Directory of Open Access Journals (Sweden)

    K. Ishizaka, R. Eguchi, S. Tsuda, T. Kiss, T. Shimojima, T. Yokoya, S. Shin, T. Togashi, S. Watanabe, C.-T. Chen, C.Q. Zhang, Y. Takano, M. Nagao, I. Sakaguchi, T. Takenouchi and H. Kawarada

    2006-01-01

    Full Text Available We have investigated the low-energy electronic state of boron-doped diamond thin film by the laser-excited photoemission spectroscopy. A clear Fermi-edge is observed for samples doped above the semiconductor–metal boundary, together with the characteristic structures at 150×n meV possibly due to the strong electron–lattice coupling effect. In addition, for the superconducting sample, we observed a shift of the leading edge below Tc indicative of a superconducting gap opening. We discuss the electron–lattice coupling and the superconductivity in doped diamond.

  16. Plasma Processing of Boron-Doped Nano-Crystalline Diamond Thin Film Fabricated on Poly-Crystalline Diamond Thick Film

    International Nuclear Information System (INIS)

    Plasma treatments of boron-doped nano-crystalline diamond (NCD) thin films were carried out in order to improve their electrical properties of the films. Boron-doped NCD thin films were fabricated on well polished poly-crystalline diamond (PCD) thick films in a microwave plasma enhanced chemical vapor deposition (MPCVD) reactor, then they were processed in methane, argon, hydrogen and B2H6 (0.1% diluted by H2) plasmas, respectively. Scanning electron microscopy (SEM) and atomic force microscope (AFM) results show that the surface morphology changed little during the 10 min treatment. Secondary ion mass spectroscopy (SIMS) results indicate that B2H6 plasma was efficient for increasing boron concentration in NCD films, while the carrier analyses demonstrates that CH4 plasma processing was effective to activate the dopants and resulted in good electrical properties.

  17. 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)

  18. 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.

  19. Electro-oxidation of diclofenac at boron doped diamond: Kinetics and mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Xu; Hou Yining; Liu Huijuan; Qiang Zhimin [State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 (China); Qu Jiuhui [State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 (China)], E-Mail: jhqu@mail.rcees.ac.cn

    2009-07-01

    Diclofenac is a common anti-inflammatory drug. Its electrochemical degradation at boron doped diamond electrode was investigated in aqueous solution. The degradation kinetics and the intermediate products were studied. Results showed that electro-oxidation was effective in inducing the degradation of diclofenac with 30 mg/L initial concentration, ensuring a mineralization degree of 72% after a 4 h treatment with the applied bias potential of 4.0 V. The effects of applied bias potential and addition of NaCl on diclofenac degradation were investigated. Different degradation mechanisms of diclofenac were involved at various applied bias potentials. With the addition of NaCl, some chlorination intermediates including dichlorodiclofenac were identified, which lead to the total organic carbon increase compared with the electrolysis process without NaCl addition at the reaction initial period. The main intermediates including 2,6-dichlorobenzenamine, 2,5-dihydroxybenzyl alcohol, and benzoic acid are identified at the time of 2 h. 1-(2,6-Dichlorocyclohexa-2,4-dienyl)indolin-2-one were also identified. These intermediates disappeared gradually with the extension of reaction time. Small molecular acids were identified finally. Based on these results, a degradation pathway of diclofenac was proposed.

  20. 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.

  1. Boron-doped diamond — Grained Mott's metal revealing superconductivity

    Czech Academy of Sciences Publication Activity Database

    Mareš, Jiří J.; Hubík, Pavel; Nesládek, M.; Krištofik, Jozef

    2007-01-01

    Roč. 16, - (2007), s. 921-925. ISSN 0925-9635 R&D Projects: GA AV ČR IAA1010404; GA ČR(CZ) GA202/06/0040 Institutional research plan: CEZ:AV0Z10100521 Keywords : diamond films * superconductivity * granular systems Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.788, year: 2007

  2. 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...

  3. 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)

  4. 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

  5. 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...

  6. 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)

  7. 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

  8. On unconventional superconductivity in boron-doped diamond

    Czech Academy of Sciences Publication Activity Database

    Mareš, Jiří J.; Nesládek, M.; Hubík, Pavel; Kindl, Dobroslav; Krištofik, Jozef

    2007-01-01

    Roč. 16, - (2007), s. 1-5. ISSN 0925-9635 R&D Projects: GA AV ČR IAA1010404; GA ČR GA202/03/0410; GA ČR(CZ) GA202/06/0040 Institutional research plan: CEZ:AV0Z10100521 Keywords : diamond film * superconductivity * nanocrystalline * electrical conductivity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.788, year: 2007

  9. Quantum transport in boron-doped nanocrystalline diamond

    Czech Academy of Sciences Publication Activity Database

    Mareš, Jiří J.; Hubík, Pavel; Krištofik, Jozef; Kindl, Dobroslav; Nesládek, Miloš

    2008-01-01

    Roč. 14, č. 7-8 (2008), s. 161-172. ISSN 0948-1907 R&D Projects: GA ČR GA202/07/0525; GA AV ČR IAA1010404; GA ČR(CZ) GA202/06/0040 Institutional research plan: CEZ:AV0Z10100521 Keywords : nanocrystalline diamond film * ballistic transport * superconductivity * Josephson’s effects Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.483, year: 2008

  10. 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...

  11. 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...

  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. Amperometric Determination of Sulfite by Gas Diffusion-Sequential Injection with Boron-Doped Diamond Electrode

    Science.gov (United States)

    Chinvongamorn, Chakorn; Pinwattana, Kulwadee; Praphairaksit, Narong; Imato, Toshihiko; Chailapakul, Orawon

    2008-01-01

    A gas diffusion sequential injection system with amperometric detection using a boron-doped diamond electrode was developed for the determination of sulfite. A gas diffusion unit (GDU) was used to prevent interference from sample matrices for the electrochemical measurement. The sample was mixed with an acid solution to generate gaseous sulfur dioxide prior to its passage through the donor channel of the GDU. The sulfur dioxide diffused through the PTFE hydrophobic membrane into a carrier solution of 0.1M phosphate buffer (pH 8)/0.1% sodium dodecyl sulfate in the acceptor channel of the GDU and turned to sulfite. Then the sulfite was carried to the electrochemical flow cell and detected directly by amperometry using the boron-doped diamond electrode at 0.95 V (versus Ag/AgCl). Sodium dodecyl sulfate was added to the carrier solution to prevent electrode fouling. This method was applicable in the concentration range of 0.2-20 mg SO32−/L and a detection limit (S/N = 3) of 0.05 mg SO32−/L was achieved. This method was successfully applied to the determination of sulfite in wines and the analytical results agreed well with those obtained by iodimetric titration. The relative standard deviations for the analysis of sulfite in wines were in the range of 1.0-4.1 %. The sampling frequency was 65 h−1.

  14. 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.

  15. 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.

  16. 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.

  17. Optoelectronic studies of boron-doped and gamma-irradiated diamond thin films

    Science.gov (United States)

    Chapagain, Puskar; Nemashkalo, Anastasiia; Peters, Raul; Farmer, John; Gupta, Sanju; Strzhemechny, Yuri M.

    2011-10-01

    Elucidation of microscopic properties of a synthetic diamond, such as formation and evolution of bulk and surface defects, chemistry of dopants, etc. is necessary for a reliable quality control and reproducibility in applications. Employing surface photovoltage (SPV) and photoluminescence (PL) spectroscopic probes we studied diamond thin films grown on silicon by microwave plasma-assisted chemical vapor deposition with different levels of boron doping in conjunction with gamma irradiation. SPV measurements showed that while the increase of boron concentration leads to a semiconductor-metal transition, subsequent intense gamma irradiation reverts back the quasi-metallic samples to semiconducting state via compensating electrical activity of boron by hydrogen. One of the most pronounced common transitions in the SPV spectra was observed at ˜3.1 eV, also present in most of the PL spectra. We argue that this is a signature of the sp^2-C clusters/layers in the vicinity of grain boundaries.

  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; Rechendorff, Kristian; Petrak, Vaclav; Nesladek, Milos; Rijkhoff, Nico; Pennisi, Cristian P.

    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. Boron-doped Diamond Electrodes: Electrochemical, Atomic Force Microscopy and Raman Study towards Corrosion-modifications at Nanoscale

    Czech Academy of Sciences Publication Activity Database

    Kavan, Ladislav; Vlčková Živcová, Zuzana; Petrák, Václav; Frank, Otakar; Janda, Pavel; Tarábková, Hana; Nesladek, M.; Mortet, Vincent

    2015-01-01

    Roč. 179, OCT 2015 (2015), s. 626-636. ISSN 0013-4686 R&D Projects: GA ČR GA13-31783S Institutional support: RVO:61388955 ; RVO:68378271 Keywords : Raman spectroelectrochemistry * atomic force microscopy * boron doped diamond Subject RIV: CG - Electrochemistry; BM - Solid Matter Physics ; Magnetism (FZU-D) Impact factor: 4.504, year: 2014

  20. Electrochemical degradation of PNP at boron-doped diamond and platinum electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yanrong, E-mail: yanrong_zhang@mail.hust.edu.cn [Environmental Science Research Institute, Huazhong University of Science and Technology, Wuhan 430074 (China); Yang, Nan [Environmental Science Research Institute, Huazhong University of Science and Technology, Wuhan 430074 (China); Murugananthan, Muthu [Dept of Chemistry and Applied Chemistry, PSG College of Technology, Peelamedu, Coimbatore 641 004 (India); Yoshihara, Sachio [Department of Energy and Environmental Science, Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585 (Japan)

    2013-01-15

    Highlights: ► Low concentration of Cl{sup −} could improve the removal of PNP. ► High chlorine concentration inhibited the COD removal. ► BDD electrode was highly effective for the conversion of PNP to organic acids. ► Accumulation of degradation intermediates was happened at Pt electrode. -- Abstract: The electrochemical degradation of p-nitrophenol (PNP) at boron-doped diamond (BDD) and platinum (Pt) anodes was studied by varying the parameters such as Cl{sup −} concentration, pH of aqueous medium and applied current density. The results obtained were explained in terms of in situ concomitant generation of hydroxyl radicals and chloride based oxidant species. The degradation of PNP was highly promoted in low concentration of NaCl electrolyte (less than 0.10 M), on contrary, the mineralization efficiency was poor at both BDD and Pt anodes with the NaCl concentration up to 0.20 M, which was ascribed to the formation of refractory chlorinated organic compounds. A maximum of 100% and 70% of COD removal was achieved in 5 h of electrolysis period using both BDD and Pt anodes under similar experimental conditions. Kinetic study indicated that the degradation of PNP at BDD and Pt anodes followed pseudo-first-order reactions, and the reaction rate constant (k{sub s}) of the former was observed to be higher than that of the latter. Besides COD, conversion of PNP into various intermediate compounds and their degradations were also monitored. The mechanisms for PNP degradation at BDD and Pt anodes were proposed separately by considering the nature of respective intermediate species and their concentrations.

  1. 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

  2. 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)

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. Electrolyte influence on the Cu nanoparticles electrodeposition onto boron doped diamond electrode

    International Nuclear Information System (INIS)

    This paper presents the electrolyte influence on deposition and dissolution processes of Cu nanoparticles on boron doped diamond electrodes (DDB). Morphological, structural and electrochemical analysis showed BDD films with good reproducibility, quality and reversible in a specific redox system. Electrodeposition of Cu nanoparticles on DDB electrodes in three different solutions was influenced by pH and ionic strength of the electrolytic medium. Analyzing the process as function of the scan rate, it was verified a better efficiency in 0,5 mol L-1 Na2SO4 solution. Under the influence of the pH and ionic strength, Cu nanoparticles on DDB may be obtained with different morphologies and it was important for defining the desired properties. (author)

  8. 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.

  9. Electroanalysis of Hydrogen Peroxide at Boron Doped Diamond Electrode Modified by Silver Nanoparticles and Haemoglobin

    International Nuclear Information System (INIS)

    The electrochemical detection of H2O2 using boron doped diamond electrode modified by silver nanoparticles and haemoglobin is reported. Silver nanoparticle obtained from electrodeposition in the presence of cetyl hexadecylthmoniom bromide (CTAB) surfactant shows the best combination of detection limit, sensitivity and reproducibility. The presence of Ag nanoparticles helps bind haemoglobin to the electrode in an active form, leading to a significantly further increase of electrode response to H2O2. Detection limits below 1 μM are achieved by a synergistic effect of both modifiers, and a good linear signal response is seen up to 8 mM. Interferences from glucose, uric acid, ascorbic acid and dopamine at typical physiological levels are shown to be negligible

  10. Continuous electrooxdiation of sulfuric acid on boron-doped diamond electrodes

    International Nuclear Information System (INIS)

    Highlights: • highly concentrated sulfuric acid was electrochemically oxidized to peroxosulfuric compounds • Diachem® boron-doped diamond electrodes were used both as anode and cathode to oxidize the sulfuric acid • a manufactured cation selective membrane was used in an unconventional electrolyte circuit • concentrations equivalent to a common SPM bath were reached • an alternative setup was applied using only one electrolyte circuit - ABSTRACT: This study reports on the electrochemical oxidation of highly concentrated sulfuric acid by Diachem® boron-doped diamond electrodes. The scope of this work was to evaluate a proposed continuous electrooxidation process in order to prepare a resist removal bath that contains equivalent amounts of peroxosulfuric compounds as a common SPM (sulfuric acid and hydrogen peroxide mixture) bath. The electrochemical processes at the electrode surface were investigated by cyclic voltammetry and by titration of the reaction products under real working conditions (> 80 wt% H2SO4). Furthermore, an alternative electrolysis test cell setup, exhibiting a thin and mechanically stable ion exchange membrane will be used. For this process only one electrolyte circuit is performed. The initial electrolysis product H2S2O8 immediately undergoes hydrolysis and forms H2SO5. The obtained concentration of H2SO5 was similar to a reference SPM bath (> 0.14 mol l−1 H2SO5 in 90 wt% H2SO4), even though the current efficiency was lower than for more diluted solutions. This can be attributed to a complex interplay of side and consumption reactions of peroxosulfuric compounds. This electrolysis bath has the potential to be a very promising alternative to standard SPM baths, as it operates as a continuous and sustainable process

  11. 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.

  12. 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.

  13. 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.

  14. Boron Doped Diamond Electrode: Spectro/Photo/Electrochemistry and Prospective Application in Dye-Sensitized Solar Cell

    Czech Academy of Sciences Publication Activity Database

    Kavan, Ladislav; Vlčková Živcová, Zuzana; Krýsová, Hana; Petrák, Václav; Bartoň, Jan; Cígler, Petr; Nesládek, M.

    Angra dos Reis: International Society of Electrochemistry , 2015. 97. [Topical Meeting of the International Society of Electrochemistry . Electrochemical Properties and Applications of Advanced Carbon Materials /16./. 22.03.2015-26.03.2015, Angra dos Reis] R&D Projects: GA ČR GA13-31783S Institutional support: RVO:61388955 ; RVO:68378271 ; RVO:61388963 Keywords : boron doped diamond electrode * electrochemistry * dye-sensitized solar cell Subject RIV: CG - Electrochemistry

  15. Resistance to protein adsorption and adhesion of fibroblasts on nanocrystalline diamond films: the role of topography and boron doping

    Czech Academy of Sciences Publication Activity Database

    Alcaide, M.; Papaioannou, S.; Taylor, Andrew; Fekete, Ladislav; Gurevich, L.; Zachar, V.; Pennisi, C.P.

    2016-01-01

    Roč. 27, č. 5 (2016), s. 90. ISSN 0957-4530 Grant ostatní: FUNBIO(XE) CZ.2.16/3.1.00/21568; FUNBIO(XE) CZ.2.16/3.1.00/21568 Institutional support: RVO:68378271 Keywords : protein adsorption * fibroblasts adhesion * nanocrystalline diamond * boron doping * topography Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.587, year: 2014

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

    OpenAIRE

    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 wi...

  17. Electrochemistry and in situ Raman spectroelectrochemistry of low and high quality boron doped diamond layers in aqueous electrolyte solution

    Czech Academy of Sciences Publication Activity Database

    Vlčková Živcová, Zuzana; Frank, Otakar; Petrák, Václav; Tarábková, Hana; Vacík, Jiří; Nesládek, M.; Kavan, Ladislav

    2013-01-01

    Roč. 87, JAN 2013 (2013), s. 518-525. ISSN 0013-4686 R&D Projects: GA AV ČR IAA400400804; GA AV ČR KAN200100801 Grant ostatní: European Commission CORDIS(XE) FP7-ENERGY-2010-FET, projekt 256617 Institutional support: RVO:61389005 ; RVO:61388955 ; RVO:68378271 Keywords : boron doped diamond * electrochemistry * aqueous electrolyte solution Subject RIV: CG - Electrochemistry Impact factor: 4.086, year: 2013

  18. 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

  19. Amperometric Determination of Sulfite by Gas Diffusion- Sequential Injection with Boron-Doped Diamond Electrode

    Directory of Open Access Journals (Sweden)

    Orawon Chailapakul

    2008-03-01

    Full Text Available A gas diffusion sequential injection system with amperometric detection using aboron-doped diamond electrode was developed for the determination of sulfite. A gasdiffusion unit (GDU was used to prevent interference from sample matrices for theelectrochemical measurement. The sample was mixed with an acid solution to generategaseous sulfur dioxide prior to its passage through the donor channel of the GDU. Thesulfur dioxide diffused through the PTFE hydrophobic membrane into a carrier solution of 0.1 M phosphate buffer (pH 8/0.1% sodium dodecyl sulfate in the acceptor channel of theGDU and turned to sulfite. Then the sulfite was carried to the electrochemical flow cell anddetected directly by amperometry using the boron-doped diamond electrode at 0.95 V(versus Ag/AgCl. Sodium dodecyl sulfate was added to the carrier solution to preventelectrode fouling. This method was applicable in the concentration range of 0.2-20 mgSO32−/L and a detection limit (S/N = 3 of 0.05 mg SO32−/L was achieved. This method wassuccessfully applied to the determination of sulfite in wines and the analytical resultsagreed well with those obtained by iodimetric titration. The relative standard deviations forthe analysis of sulfite in wines were in the range of 1.0-4.1 %. The sampling frequency was65 h−1.

  20. Optoelectronic surface-related properties in boron-doped and irradiated diamond thin films

    Science.gov (United States)

    Nemashkalo, A.; Chapagain, P. R.; Peters, R. M.; Farmer, J.; Gupta, S.; Strzhemechny, Y. M.

    2012-01-01

    Elucidation of microscopic properties of synthetic diamond films, such as formation and evolution of bulk and surface defects, chemistry of dopants, is necessary for a reliable quality control and reproducibility in applications. Surface photovoltage (SPV) spectroscopy and photoluminescence (PL) spectroscopy were employed to study diamond thin films grown on silicon by microwave plasma-assisted chemical vapor deposition and hot-filament chemical vapor deposition with different levels of boron doping in conjunction with gamma irradiation. SPV experiments showed that while the increase of boron concentration leads to a semiconductor-metal transition, subsequent gamma irradiation reverts quasi-metallic samples back to a semiconducting state by compensating electrical activity of boron possibly via hydrogen. One of the most pronounced common transitions observed at ˜3.1-3.2 eV in the SPV spectra was also present in all of the PL spectra. It is likely that this is a signature of the sp2-hybridized carbon clusters in or in the vicinity of grain boundaries.

  1. Optoelectronic surface-related properties in boron-doped and irradiated diamond thin films

    International Nuclear Information System (INIS)

    Elucidation of microscopic properties of synthetic diamond films, such as formation and evolution of bulk and surface defects, chemistry of dopants, is necessary for a reliable quality control and reproducibility in applications. Surface photovoltage (SPV) spectroscopy and photoluminescence (PL) spectroscopy were employed to study diamond thin films grown on silicon by microwave plasma-assisted chemical vapor deposition and hot-filament chemical vapor deposition with different levels of boron doping in conjunction with gamma irradiation. SPV experiments showed that while the increase of boron concentration leads to a semiconductor-metal transition, subsequent gamma irradiation reverts quasi-metallic samples back to a semiconducting state by compensating electrical activity of boron possibly via hydrogen. One of the most pronounced common transitions observed at ∼3.1-3.2 eV in the SPV spectra was also present in all of the PL spectra. It is likely that this is a signature of the sp2-hybridized carbon clusters in or in the vicinity of grain boundaries.

  2. Energy consumption of electrooxidation systems with boron-doped diamond electrodes in the pulse current mode

    Science.gov (United States)

    Wei, Jun-jun; Gao, Xu-hui; Hei, Li-fu; Askari, Jawaid; Li, Cheng-ming

    2013-01-01

    A pulse current technique was conducted in a boron-doped diamond (BDD) anode system for electrochemical wastewater treatment. Due to the strong generation and weak absorption of hydroxyl radicals on the diamond surface, the BDD electrode possesses a powerful capability of electrochemical oxidation of organic compounds, especially in the pulse current mode. The influences of pulse current parameters such as current density, pulse duty cycle, and frequency were investigated in terms of chemical oxygen demand (COD) removal, average current efficiency, and specific energy consumption. The results demonstrated that the relatively high COD removal and low specific energy consumption were obtained simultaneously only if the current density or pulse duty cycle was adjusted to a reasonable value. Increasing the frequency slightly enhanced the COD removal and average current efficiency. A pulse-BDD anode system showed a stronger energy saving ability than a constant-BDD anode system when the electrochemical oxidation of phenol of the two systems was compared. The results prove that the pulse current technique is more cost-effective and more suitable for a BDD anode system for real wastewater treatment. A kinetic analysis was presented to explain the above results.

  3. 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

  4. Assessment of Electrodes Prepared from Wafers of Boron-doped Diamond for the Electrochemical Oxidation of Waste Lubricants

    International Nuclear Information System (INIS)

    Electrochemical oxidation using boron-doped diamond electrodes is being investigated as a treatment process for radioactively contaminated oily wastes. Previously, it was shown that electrodes coated with a thin film of diamond were able to oxidise a cutting oil but not a mineral oil. These tests were inconclusive, because the electrodes lost their diamond coating during operation. Accordingly, an electrode prepared from a 'solid' wafer of boron-doped diamond is being investigated to determine whether it will oxidise mineral oils. The electrode has been tested with sucrose, a cutting oil and an emulsified mineral oil. Before and after each test, the state of the electrode was assessed by cyclic voltammetry with the ferro/ferricyanide redox couple. Analysis of the cyclic voltammogram suggested that material accumulated on the surface of the electrode during the tests. The magnitude of the effect was in the order: - emulsified mineral oil > cutting oil > sucrose. Despite this, the results indicated that the electrode was capable of oxidising the emulsified mineral oil. Confirmatory tests were undertaken in the presence of alkali to trap the carbon dioxide, but they had to be abandoned when the adhesive holding the diamond in the electrode was attacked by the alkali. Etching of the diamond wafer was also observed at the end of the tests. Surface corrosion is now regarded as an intrinsic part of the electrochemical oxidation on diamond, and it is expected that the rate of attack will determine the service life of the electrodes. (authors)

  5. 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

  6. HPHT Synthesis of Micron Grade Boron-Doped Diamond Single Crystal in Fe-Ni-C-B Systems

    International Nuclear Information System (INIS)

    Micron grade boron-doped diamond crystals with octahedral morphology are successfully synthesized in a Fe—Ni—C—B system under high pressure and high temperature (HPHT). The effects of the additive boron on synthesis conditions, nucleation and growth, crystal morphology of diamond are studied. The synthesized micron grade diamond crystals were characterized by optical microscope (OM), scanning electron microscope (SEM), x-ray diffraction (XRD) and Raman spectroscopy. The research results show that the V-shaped section of synthetic diamond moves downwards to the utmost extent due to 0.3a wt% (a is a constant.) boron added in the synthesis system. The crystal colour is black, and the average crystal size is about 25 μm. The crystal faces of synthetic diamond are mainly {111} face. The synthesis of this kind of diamond is few reported, and it will have important and widely applications. (cross-disciplinary physics and related areas of science and technology)

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. Degradation of microcystin-RR using boron-doped diamond electrode

    International Nuclear Information System (INIS)

    Microcystins (MCs), produced by blue-green algae, are one of the most common naturally occurring toxins found in natural environment. The presence of MCs in drinking water sources poses a great threat to people's health. In this study, the degradation behavior of microcystin-RR on boron-doped diamond (BDD) electrode was investigated under galvanostatic conditions. Such parameters as reaction time, supporting electrolyte and applied current density were varied in order to determine their effects on this oxidation process. The experimental results revealed the suitability of electrochemical processes employing BDD electrode for removing MC-RR from the solution. However, the efficient removal of MC-RR only occurred in the presence of sodium chloride that acted as redox mediators and the reaction was mainly affected by the chloride concentration (cNaCl) and applied current density (Iappl). Full and quick removal of 0.50 μg/ml MC-RR in solution was achieved when the operating conditions of cNaCl and Iappl were 20 mM and 46.3 mA/cm2, or 35 mM and 18.2 mA/cm2 respectively. The kinetics for MC-RR degradation followed a pesudo-first order reaction in most cases, indicating the process was under mass transfer control. As a result of its excellent performance, the BDD technology could be considered as a promising alternative to promote the degradation of MC-RR than chlorination in drinking water supplies.

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

    International Nuclear Information System (INIS)

    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/cm2), electrolyte concentration (0.1–0.5 M HClO4), initial solution pH (1–12.3) and temperature (22–43 °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.

  17. 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.

  18. Determination of trace amounts of uranium by stripping voltammetry using a boron-doped diamond electrode

    International Nuclear Information System (INIS)

    Stripping voltammetry using a boron-doped diamond (BDD)-electrode is described for the determination of uranium. A uranium solution adjusted to pH 3 was supplied to the surface of an electrode continuously by a carrier solution at 0.10 mL min-1, and uranium in the solution was accumulated. An accumulation potential of -2.5 V (vs. Ag/AgCl) was applied to the BDD-electrode. After the accumulation step, the flow of the carrier solution was stopped and the stripping voltammogram, ranging from -2.5 V to 1.0 V (vs. Ag/AgCl), was recorded. A linear relationship between the stripping peak current and the uranium concentration existed in the range from 0 to 1270 ng mL-1, and the relative standard deviation of five repeated analyses was approximately 5% for 0.50 mL of an uranium standard solution of 127 ng mL-1. The method was applied to the determination of uranium in low active liquid wastes from a spent nuclear-fuel reprocessing plant. (author)

  19. 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

  20. Anodic oxidation of 1,4-dioxane on boron-doped diamond electrodes for wastewater treatment

    International Nuclear Information System (INIS)

    A study of the anodic oxidation of 1,4-dioxane, a refractory water pollutant, by boron-doped diamond (BDD) electrodes was carried out under a range of major system variables: initial concentration, current density, temperature, pH, and electrolyte concentration. The 1,4-dioxane removal behavior was monitored by chemical oxygen demand (COD), and the results were compared with theoretical models for the electrochemical incineration of organic compounds. The removal efficiency of COD was shown to be greater than 95% in most cases, and no electrode fouling was observed during the reaction. Experimental degradation behavior agreed well with the theoretical models, implying that system variables can be predicted, even when the process is applied at pilot scale. Processes conducted at lower initial concentrations and higher temperatures yielded better energy consumption efficiency. Conditions of higher current density yielded faster degradation but need greater quantities of charge loading into the system. Therefore, a compromise between treatment time and energy consumption is required to achieve the desired efficiency. Meanwhile, pH and electrolyte concentrations did not affect reaction efficiency, suggesting that pH adjustment prior to wastewater treatment is not necessary. Thus, anodic oxidation of 1,4-dioxane by BDD electrodes promises to be both an economical and an efficient in wastewater treatment process.

  1. 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

  2. H-terminated polycrystalline boron doped diamond electrode for geochemical sensing into underground components of nuclear repositories

    International Nuclear Information System (INIS)

    Document available in extended abstract form only. 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 management of long-term safety, reversibility and retrievability. Among the chemical parameters, the most significant are pH, conductivity and redox potential. Wide band gap semiconductors are favored materials for chemical sensing because of their high stability to many chemical agents. Among the wide band gap materials, Chemical Vapor Deposition (CVD) boron doped diamond (BDD) benefits from a large band gap, which gives rise to a wide electrochemical potential window. It is moreover described as a radiation, corrosion and bio-corrosion resistant. These remarkable properties, in addition to a low double layer capacity and a low residual current, make BDD a promising material for geochemical sensor elaboration. This work aimed to investigate BDD- based electrodes coated with p-type polycrystalline BDD-hydrogen- terminated surfaces (1 cm2) for pH and/or redox measurements into the underground components of nuclear repositories. The boron-doped p-type channel was grown in a microwave plasma reactor (BJS 150). The boron-doped channel was hydrogen terminated by a hydrogen plasma treatment in the CVD reactor, resulting in full saturation of the surface carbon bonds with hydrogen atoms. Scanning Electron Microscopy (SEM) of the polycrystalline BDD coating with a Bore/Carbon ratio of 500 ppm shows the typical columnar growth of the polycrystalline CVD diamond. A homogeneous surface was observed concerning the crystallite size which average

  3. Sulfate-mediated electrooxidation of X-ray contrast media on boron-doped diamond anode.

    Science.gov (United States)

    Radjenovic, Jelena; Petrovic, Mira

    2016-05-01

    Recently, electrochemical activation of sulfate ions to sulfate radical species and nonradically activated persulfate has been demonstrated at boron-doped diamond (BDD) anode, which enhanced the electrooxidation kinetics of several persistent contaminants. In this study, we investigated the transformation pathways of two X-ray contrast media (ICM), diatrizoate and iopromide, in electrooxidation at BDD anode using sulfate and inert nitrate anolyte. Sulfate anolyte yielded a seven-fold increase in apparent rate constants for ICM oxidation compared to inert nitrate anolyte, and a two-fold increase for the removal of organic carbon. Higher iodine release was observed in electrooxidation of diatrizoate compared to iopromide. In the case of diatrizoate, around 80% of deiodination efficiency was achieved in both anolytes. Deiodination efficiency of iopromide was somewhat lower in nitrate anolyte (≤75%) and significantly reduced in sulfate anolyte (≤46%) due to a larger steric hindrance of alkyl side chains. Moreover, a considerable lag phase of iopromide deiodination was observed in sulfate anolyte, indicating that initial oxidation reactions took place almost exclusively at the alkyl side chains. Several transformation products (TPs) of ICM were identified in electrooxidation in sulfate anolyte, and only three TPs in the case of nitrate anolyte. The main mechanistic steps in the oxidation of iopromide were H-abstraction and bond cleavage in the alkyl side chains. Diatrizoate was mainly transformed through oxidative cleavage of iodine substituent and inter-molecular cyclization. Two hydroxylamine derivatives of iopromide and a nitro-derivative of diatrizoate were observed in sulfate anolyte. These products have not been reported previously for hydroxyl radical-mediated oxidation of ICM. Given that electron-transfer mechanism is more typical for sulfate than for hydroxyl radicals, formation of hydroxylamine and nitro-derivatives of ICM was assigned to one

  4. Degradation of perfluorinated compounds on a boron-doped diamond electrode

    International Nuclear Information System (INIS)

    Highlights: ► The first order kinetic constants of PFCs depend on chain length. ► BDD has good electrochemical performances and high current efficiency at 0.59 mA cm−2. ► The intermediate products of PFCs decomposition were short chain PFCAs. - Abstract: Perfluorinated compounds (PFCs) are persistent in environments due to the high energy of C-F bond. Electrochemical oxidation of seven PFCs in aqueous solution on a boron doped diamond (BDD) anode was studied in this study. The kinetics results show that the pseudo-first order kinetic constants of perfluoroalkyl carboxyates and sulfonates increased with the increase of carbon chain length. PFCs decomposition began with a direct one electron transfer from carboxyl or sulfonate group to BDD, and the formed PFCs radicals were decarboxylated or desulfonated to yield the perfluoroalkyl radical which permitted a defluorination reaction between perfluoroalkyl radical and hydroxyl radical. The effects of potential, current density, initial pH, and perfluorooctanoate (PFOA) concentration on the removal of PFOA were investigated. The anodic potential played an important role in the decomposition, and the oxidation potential of PFOA was 2.76 vs. SCE/V (saturated calomel electrode). When the current density increased slightly from 0.12 to 0.59 mA cm−2, PFOA removal was greatly enhanced from 0 to 97.48%. PFOA decomposition was higher in acidic solution compared to that in the alkaline solution. The pseudo-first order kinetic constants of PFOA decomposition increased with the increase of initial concentration.

  5. 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

  6. 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.

  7. Semiconducting to metallic-like boron doping of nanocrystalline diamond films and its effect on osteoblastic cells

    Czech Academy of Sciences Publication Activity Database

    Kromka, Alexander; Grausová, Ľubica; Bačáková, Lucie; Vacík, Jiří; Rezek, Bohuslav; Vaněček, Milan; Williams, O.A.; Haenen, K.

    2010-01-01

    Roč. 19, 2-3 (2010), s. 190-195. ISSN 0925-9635 R&D Projects: GA AV ČR KAN400100701; GA AV ČR(CZ) KAN400480701; GA MŠk LC510; GA AV ČR(CZ) IAAX00100902 Institutional research plan: CEZ:AV0Z10100521; CEZ:AV0Z50110509; CEZ:AV0Z10480505 Keywords : nanocrystalline diamond * boron doping * atomic force microscopy * tissue engineering Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.825, year: 2010

  8. Monitoring of peptide induced disruption of artificial lipid membrane constructed on boron-doped nanocrystalline diamond by electrochemical impedance spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Petrák, V.; Grieten, L.; Taylor, Andrew; Fendrych, František; Ledvina, Miroslav; Janssens, S. D.; Nesládek, M.; Haenen, K.; Wagner, P.

    2011-01-01

    Roč. 208, č. 9 (2011), s. 2099-2103. ISSN 1862-6300 R&D Projects: GA AV ČR KAN200100801; GA AV ČR(CZ) KAN400480701; GA MŠk(CZ) LD11076 Grant ostatní: European RD projects(XE) 238201-MATCON Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z10100520 Keywords : biosensor * boron-doped nanocrystalline diamond * electrochemical impedance spectroscopy Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.463, year: 2011

  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. 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.

  11. Indirect Voltammetric Sensing Platforms For Fluoride Detection on Boron-Doped Diamond Electrode Mediated via [FeF6]3− and [CeF6]2− Complexes Formation

    International Nuclear Information System (INIS)

    Very simple and sensitive electroanalytical technique based on synergistic combination of reaction electrochemistry (specificity) and bare boron-doped diamond electrode (sensitivity) for the detection of fluorides in drinking water was developed as variant based on dynamic electrochemistry to ISE analysis. It is based on the formation of electroinactive fluoride complexes with Fe(III) and Ce(IV) ions decreasing such diffusion current of free metal on boron-doped diamond electrode. Due to low background signal of boron-doped diamond electrode reasonably low detection limits of the order of 10−6 mol L−1 for linear sweep voltammetric method using formation of [FeF6]3− and 10−7 mol L−1 in a square-wave variant of this technique have been achieved. This is approximately 1–2 orders lower than in the case of platinum comb-shaped interdigitated microelectrode array. Linear sweep voltammetric method based on [CeF6]2− complex formation has lower sensitivity and may be suitable for samples with higher content of fluoride and not to analysis of drinking water

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

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

    International Nuclear Information System (INIS)

    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-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 μmol L-1 in a BR buffer solution (pH 2.0), with a detection limit of 0.90 μmol L-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)

  19. 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

  20. 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

  1. 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...

  2. 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.

  3. 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.

  4. 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...

  5. Large area deposition of boron doped nano-crystalline diamond films at low temperatures using microwave plasma enhanced chemical vapour deposition with linear antenna delivery

    Czech Academy of Sciences Publication Activity Database

    Taylor, Andrew; Fekete, Ladislav; Hubík, Pavel; Jäger, Aleš; Janíček, P.; Mortet, Vincent; Mistrík, J.; Vacík, Jiří

    2014-01-01

    Roč. 47, AUG (2014), s. 27-34. ISSN 0925-9635 R&D Projects: GA MŠk(CZ) LM2011026; GA MŠk(XE) LM2011019 Institutional support: RVO:68378271 ; RVO:61389005 Keywords : large area * low temperature * boron doped nano-crystalline diamond * linear antenna MW PE CVD Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.919, year: 2014

  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. 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.

  8. 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.

  9. 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...

  10. 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...

  11. Electrochemical degradation of a real textile effluent using boron-doped diamond or β-PbO2 as anode

    International Nuclear Information System (INIS)

    Highlights: · Diamond anode enables total abatement of a real textile effluent COD with low energy consumption. · Use of diamond anode enables excellent decolorization rate of effluent in the presence of Cl- ions. · Diamond anode might be an excellent option for electrochemical treatment of real textile effluents. · PbO2 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/β-PbO2 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-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/β-PbO2 anode, at any experimental condition. The best conditions are j = 5 mA cm-2 and 55 oC, 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 (Qap) of only about 2 kA h m-3. Practically total abatement of the effluent COD is attained with the Nb/BDD anode using a Qap value of only 7 kA h m-3, with an energy consumption of about 30 kW h m-3. This result allows to conclude that the Nb/BDD electrode might be an excellent option for the remediation of textile effluents.

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

    International Nuclear Information System (INIS)

    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 <10−3 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 sp3 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

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

    International Nuclear Information System (INIS)

    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-1 H2SO4 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-1 (r2 = 0.999), with a detection limit of 7.1 μmol L-1 for PC and 3.8 μmol L-1 for IB. The addition-recovery studies in samples were about 100% and the results were validated by chromatographic methods. (author)

  14. 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

  15. 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)

  16. Application of electrochemical technology for removing petroleum hydrocarbons from produced water using lead dioxide and boron-doped diamond electrodes.

    Science.gov (United States)

    Gargouri, Boutheina; Gargouri, Olfa Dridi; Gargouri, Bochra; Trabelsi, Souhel Kallel; Abdelhedi, Ridha; Bouaziz, Mohamed

    2014-12-01

    Although diverse methods exist for treating polluted water, the most promising and innovating technology is the electrochemical remediation process. This paper presents the anodic oxidation of real produced water (PW), generated by the petroleum exploration of the Petrobras plant-Tunisia. Experiments were conducted at different current densities (30, 50 and 100 mA cm(-2)) using the lead dioxide supported on tantalum (Ta/PbO2) and boron-doped diamond (BDD) anodes in an electrolytic batch cell. The electrolytic process was monitored by the chemical oxygen demand (COD) and the residual total petroleum hydrocarbon [TPH] in order to know the feasibility of electrochemical treatment. The characterization and quantification of petroleum wastewater components were performed by gas chromatography mass spectrometry. The COD removal was approximately 85% and 96% using PbO2 and BDD reached after 11 and 7h, respectively. Compared with PbO2, the BDD anode showed a better performance to remove petroleum hydrocarbons compounds from produced water. It provided a higher oxidation rate and it consumed lower energy. However, the energy consumption and process time make useless anodic oxidation for the complete elimination of pollutants from PW. Cytotoxicity has shown that electrochemical oxidation using BDD could be efficiently used to reduce more than 90% of hydrocarbons compounds. All results suggest that electrochemical oxidation could be an effective approach to treat highly concentrated organic pollutants present in the industrial petrochemical wastewater and significantly reduce the cost and time of treatment. PMID:25129707

  17. 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.

  18. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    Murugananthan, M., E-mail: muruga.chem@gmail.com [National Metallurgical Laboratory Madras Centre, CSIR Madras Complex, Taramani, Chennai 600 113 (India); Latha, S.S.; Bhaskar Raju, G. [National Metallurgical Laboratory Madras Centre, CSIR Madras Complex, Taramani, Chennai 600 113 (India); Yoshihara, S. [Department of Advanced Interdisciplinary Science, Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585 (Japan)

    2010-08-15

    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 ({center_dot}OH), peroxodisulfate (S{sub 2}O{sub 8}{sup 2-}), and active chlorine species (Cl{sub 2}, HOCl, OCl{sup -}). The physisorbed {center_dot}OH on BDD was observed to trigger the combustion of KP in to CO{sub 2} and H{sub 2}O. 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 Na{sub 2}SO{sub 4} as supporting electrolyte.

  20. 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. PMID:18585340

  1. Flow-injection determination of iodide ion in nuclear emergency tablets, using boron-doped diamond thin film electrode

    International Nuclear Information System (INIS)

    The electrochemical determination of iodide was studied at boron-doped diamond thin film electrodes (BDD) using cyclic voltammetry (CV) and flow-injection (FI) analysis, with amperometric detection. Cyclic voltammetry of iodide was conducted in a phosphate buffer pH 5. Experiments were performed using glassy carbon (GC) electrode as a comparison. Well-defined oxidation waves of the quasi-reversible cyclic voltammograms were observed at both electrodes. Voltammetric signal-to-background ratios (S/B) were comparable. However, the GC electrode gives much greater in the background current as usual. The potential sweep rate dependence exhibited that the peak current of iodide oxidation at 1mM varied linearly (r2 = 0.998) with the square root of the scan rate, from 0.01 to 0.30Vs-1. This result indicates that the reaction is a diffusion-controlled process with negligible adsorption on BDD surface, at this iodide concentration. Results of the flow-injection analysis show a highly reproducible amperometric response. The linear working range was observed up to 200μM (r2 = 0.999). The detection limit, as low as 0.01μM (3σ of blank), was obtained. This method was successfully applied for quantification of iodide contents in nuclear emergency tablets

  2. 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.

  3. Determination of vanillin in commercial food product by adsorptive stripping voltammetry using a boron-doped diamond electrode.

    Science.gov (United States)

    Yardım, Yavuz; Gülcan, Mehmet; Şentürk, Zühre

    2013-12-01

    A method for the determination of food additive vanillin was developed by adsorptive stripping voltammetry. Its determination was carried out at the anodically pre-treated boron-doped diamond electrode in aqueous solutions. Using square-wave stripping mode, the compound yielded a well-defined voltammetric response in phosphate buffer, pH 2.5 at +1.14 V (vs. Ag/AgCl) (a pre-concentration step being carried out at open-circuit condition for 60s). A linear calibration graph was obtained in the concentration range of 0.5-15.0 μg mL(-1) (3.3×10(-6)-9.8×10(-5) mol L(-1)) with a detection limit of 0.024 μg mL(-1) (1.6×10(-7) mol L(-1)). As an example, the practical applicability of the proposed method was tested for the determination of this flavouring agent in commercial pudding powder of Keshkule (Turkish milk pudding with almond flour). PMID:23870896

  4. 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

  5. Improving the electrochemical properties of nanosized LiFePO4-based electrode by boron doping

    International Nuclear Information System (INIS)

    Highlights: • Thermal treatment of boron phosphate with LiFePO4 provides electrode materials with high performance in lithium half-cells: 160 mAh·g-1 (90% of theoretical capacity) under C/5 rate • The products are composites containing boron-modified LiFePO4, FePO4 and an amorphous phase with ionic diffusion properties • The boron treatment affects textural, conductive and lithium diffusivity of the electrode material leading to higher performance • A limited boron-doping of the phospholivine structure is observed - Abstract: Electrode materials with homogeneous distribution of boron were obtained by heating mixtures of nanosized carbon-coated lithium iron phosphate and BPO4 in 3-9% weight at 700 °C. The materials can be described as nanocomposites containing i) LiFePO4, possibly doped with a low amount of boron, ii) FePO4 and iii) an amorphous layer based on Li4P2O7-derived material that surrounds the phosphate particles. The thermal treatment with BPO4 also triggered changes in the carbon coating graphitic order. Galvanostatic and voltammetric studies in lithium half-cells showed smaller polarisation, higher capacity and better cycle life for the boron-doped composites. For instance, one of the solids, called B6-LiFePO4, provided close to 150 and 140 mAhg-1 (87% and 81% of theoretical capacity, respectively) under C/2.5 and C regimes after several cycles. Improved specific surface area, carbon graphitization, conductivity and lithium ion diffusivity in the boron-doped phospholivine network account for this excellent rate performance. The properties of an amorphous layer surrounding the phosphate particles also account for such higher performance

  6. 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.

  7. Effect of boron doping on optical properties of sol–gel based nanostructured zinc oxide films on glass

    International Nuclear Information System (INIS)

    Graphical abstract: Room temperature fine structured UV–vis PL emissions (a) as phonon replicas in 1 at.% boron doped film originated from LO phonon evidenced from Near Grazing Incidence Angle (NGIA) IR spectral study (b). Highlights: ► Sol–gel based boron doped nanostructured ZnO thin films deposited on pure silica glass using crystalline boric acid as boron source. ► Observed first time, room temperature fine structured PL emissions in 1 at.% doped film as phonon replicas originated from LO phonon (both IR and Raman active). ► Boron doping controls the LO phonon energy in addition to visible reflection, band gap and grain size. ► The films possessed mixed crystal phases with hexagonal as major phase. -- Abstract: Boron doped zinc oxide thin films (∼80 nm) were deposited onto pure silica glass by sol–gel dip coating technique from the precursor sol/solution of 4.0 wt.% equivalent oxide content. The boron concentration was varied from 0 to 2 at.% w.r.t. Zn using crystalline boric acid. The nanostructured feature of the films was visualized by FESEM images and the largest cluster size of ZnO was found in 1 at.% boron doped film (B1ZO). The presence of mixed crystal phases with hexagonal as major phase was identified from XRD reflections of the films. Particle size, optical band gap, visible specular reflection, room temperature photoluminescence (PL) emissions (3.24–2.28 eV), infra-red (IR) and Raman active longitudinal optical (LO) phonon vibration were found to be dependent on dopant concentration. For the first time, we report the room temperature fine structured PL emissions as phonon replicas originated from the LO phonon (both IR and Raman active) in 1 at.% boron doped zinc oxide film.

  8. 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)

  9. 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)

  10. 10B and 11B high-resolution NMR studies on boron-doped diamond

    Science.gov (United States)

    Murakami, M.; Shimizu, T.; Tansho, M.; Takano, Y.; Ishii, S.; Ekimov, E. A.; Sidorov, V. A.; Takegoshi, K.

    2010-12-01

    11B magic-angle spinning (MAS) NMR experiments are applied to B-doped diamond samples prepared by high-pressure and high-temperature methods. From the spectrum, we show that there are at least four boron signal components and the one at 28.5 ppm is ascribed to the substitutional boron in the diamond structure providing the carriers responsible for conductivity. We further apply two-dimensional (2D) NMR to examine 1H dipolar broadening and 11B-11B boron spin diffusion, and candidates purported so far for the excess boron, that is, a boron + hydrogen complex and -B-B- and/or -B-C-B- clusters are negated. Furthermore, we show that 10B MAS NMR is useful to selectively observe the substitutional boron in the diamond structure appearing at 28.5 ppm, whose quadrupolar coupling is much smaller than that of the excess boron at 65.5 ppm.

  11. Simultaneous determination of paracetamol and penicillin V by square-wave voltammetry at a bare boron-doped diamond electrode

    International Nuclear Information System (INIS)

    Highlights: ► Unmodified BDD electrode = sensitive electrochemical sensor for drugs determination. ► No special pretreatment of samples except simple dilution. ► Selective method, common compounds present in urine do not interfere in high excess. ► Simultaneous determination of PAR and PEN has yet not been published in literature. - Abstract: A simple, sensitive and selective square-wave voltammetry method for simultaneous determination of paracetamol and penicillin V on a bare (unmodified) boron-doped diamond electrode has been developed. The good potential separation of about 0.35 V between the oxidation peak potentials of both drugs present in mixture was found. It was found by cyclic voltammetry that paracetamol gave quasireversible wave and penicillin V provided irreversible oxidation peak. The effect of supporting electrolyte, pH and scan rate on voltammetric response of both drugs was studied to select the optimum experimental conditions. The optimal conditions for quantitative simultaneous determination were obtained in acetate buffer solution at pH 5.0. The oxidation peak of paracetamol and penicillin V showed a systematic increase in peak currents with increase of their concentration. The calibration curves for the simultaneous determination of paracetamol and penicillin V exhibited the good linear responses within the concentration range from 0.4 to 100 μM for both drugs. The detection limit was established to 0.21 and 0.32 μM for paracetamol and penicillin V, respectively. The method proved the good sensitivity, repeatability (RSD of 1.5 and 2.1% for mixture solution of 10 μM PCM and PEN) and selectivity when influence of interferents commonly existing in human urine was negligible. The practical analytical utility of proposed method was demonstrated by simultaneous determination of paracetamol and penicillin V in human urine samples, with results similar to those obtained using a high-performance liquid chromatography method as an

  12. Electrochemical degradation of Novacron Yellow C-RG using boron-doped diamond and platinum anodes: Direct and Indirect oxidation

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Nature of electrode material decides the electrocatalytic mechanism followed. • Electrogenerated strong oxidants on BDD surface improve the color and organic load removal. • Chlorine active species act in solution cage oxidizing organic matter. - Abstract: The present study discusses the electrochemical degradation process of a textile dye, Novacron Yellow C-RG (NY), dissolved in synthetic wastewaters, via direct and indirect oxidation. Experiments were conducted using boron-doped diamond (BDD) and platinum supported on Ti (Pt/Ti) electrodes in the absence and presence of NaCl in the solution. The direct process for removing color is relatively similar for both anodes, while the electrochemical degradation is significantly accelerated by the presence of halogen salt in the solution. Interestingly, it does not depend on applied current density, but rather on NaCl concentration. Therefore, the electrochemical processes (direct/indirect) favor specific oxidation pathways depending on electrocatalytic material. Whereas, the Pt/Ti anode favors preferentially color removal by direct and indirect oxidation (100% of color removal) due to the fragmentation of the azo dye group; BDD electrode favors color and organic load removals in both processes (95% and up to 87%, respectively), due to the rupture of dye in different parts of its chemical structure. Parameters of removal efficiency and energy consumption for the electrochemical process were estimated. Finally, an explanation has been attempted for the role of halide, in relation with the oxygen evolution reaction, concomitant with the electrochemical incineration as well as electrocatalytic mechanisms, for each one of the electrodes used

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. The acceptor concentration of the polycrystalline boron doped diamond films determined using different techniques

    Czech Academy of Sciences Publication Activity Database

    Vlčková Živcová, Zuzana; Petrák, Václav; Frank, Otakar; Nesladek, M.; Kavan, Ladislav

    Hasselt: Hasselt University, 2015. s. 92-92. [Hasselt Diamond Workshop 2015, SBDD XX. 25.02.2015-27.02.2015, Hasselt] R&D Projects: GA ČR GA13-31783S Institutional support: RVO:61388955 ; RVO:68378271 Keywords : polycrystalline boron * electrochemistry Subject RIV: CG - Electrochemistry

  18. Determination of dopamine on a nanostructured boron-doped diamond electrode

    Czech Academy of Sciences Publication Activity Database

    Vojs, Marian; Behul, M.; Michniak, P.; Řeháček, V.; Redhammer, R.; Ižák, Tibor; Kromka, Alexander

    Kirchberg : Kirchberg, 2013 - (Machon, M.; Herziger, F.). s. 176-176 [International Winterschool on Electronic Properties of Novel Materials /27./. 02.03.2013-09.03.2013, Kirchberg] R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:68378271 Keywords : diamond electrode * electrochemistry * dopamin Subject RIV: BM - Solid Matter Physics ; Magnetism

  19. Selected topics related to the transport and superconductivity in boron-doped diamond

    Czech Academy of Sciences Publication Activity Database

    Mareš, Jiří J.; Hubík, Pavel; Krištofik, Jozef; Nesládek, Miloš

    2008-01-01

    Roč. 9, č. 4 (2008), 044101/1-044101/6. ISSN 1468-6996 R&D Projects: GA AV ČR IAA1010404; GA ČR(CZ) GA202/06/0040 Institutional research plan: CEZ:AV0Z10100521 Keywords : nanocrystalline diamond * temperature Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.267, year: 2008

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

    OpenAIRE

    Taylor, A C; Vagaska, B.; Edgington, R.; Hébert, C.; Ferretti, P.; Bergonzo, P.; Jackman, R. B.

    2015-01-01

    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 applica...

  1. 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

  2. Conductivity of boron-doped polycrystalline diamond films: influence of specific boron defects

    Czech Academy of Sciences Publication Activity Database

    Ashcheulov, Petr; Šebera, Jakub; Kovalenko, Alexander; Petrák, Václav; Fendrych, František; Nesládek, M.; Taylor, Andrew; Vlčková Živcová, Zuzana; Frank, Otakar; Kavan, Ladislav; Dračínský, Martin; Hubík, Pavel; Vacík, Jiří; Kraus, I.; Kratochvílová, Irena

    2013-01-01

    Roč. 86, č. 10 (2013), "443-1"-"443-9". ISSN 1434-6028 R&D Projects: GA TA ČR TA01011165; GA ČR(CZ) GAP304/10/1951; GA MŠk(XE) LM2011019; GA ČR GA13-31783S; GA MŠk(CZ) LD11076 Grant ostatní: FP7 ITN(XE) 238201-MATCON Institutional support: RVO:68378271 ; RVO:61388955 ; RVO:61388963 ; RVO:61389005 Keywords : polycrystalline diamond layer * conductivity B doping Subject RIV: BM - Solid Matter Physics ; Magnetism; CG - Electrochemistry (UFCH-W) Impact factor: 1.463, year: 2013

  3. Anodic behavior of sertindole and its voltammetric determination in pharmaceuticals and human serum using glassy carbon and boron-doped diamond electrodes

    International Nuclear Information System (INIS)

    The electrochemical oxidation of sertindole was investigated using cyclic, linear sweep voltammetry at a glassy carbon and boron-doped diamond electrodes. The aim of this study was to determine sertindole levels in serum and pharmaceutical formulations, by means of electrochemical methods. In cyclic voltammetry, depending on pH values, sertindole showed one or two irreversible oxidation responses. These two responses were found related to the different electroactive part of the molecule. Using second and sharp oxidation peak, two voltammetric methods were described for the determination of sertindole by differential pulse and square wave voltammetry at the glassy carbon and boron-doped diamond electrodes. Under optimized conditions, the current showed a linear dependence with concentration in the range between 1 x 10-6 and 1 x 10-4 M in acetate buffer at pH 3.5 and between 4 x 10-6 and 1 x 10-4 M in spiked human serum samples for both methods. The repeatability, reproducibility, selectivity, precision and accuracy of all the methods in all media were investigated and calculated. These methods were successfully applied for the analysis of sertindole pharmaceutical dosage forms and human serum samples. No electroactive interferences from the tablet excipients and endogenous substances from biological material were found

  4. The effects of surface oxidation and fluorination of boron-doped diamond anodes on perchlorate formation and organic compound oxidation

    International Nuclear Information System (INIS)

    This research investigated the effects of surface functional groups on both rates of organic compound oxidation (phenol, p-nitrophenol, benzoquinone, and oxalic acid) and perchlorate (ClO4−) formation at boron-doped diamond (BDD) film anodes at 20 °C. X-ray photoelectron spectroscopy measurements determined that various oxygenated functional groups (e.g., C-OH, C=O, COOH) were incorporated on the BDD surface by applying an anodic ageing process, and fluorine functional groups (e.g., C-F, -CnF2n+1) were incorporated by electrochemical oxidation of aqueous perfluorooctanoic acid solutions. Batch oxidation experiments revealed that ClO4− formation via the oxidation of ClO3− was highly variable during anodic ageing, which was attributed to changes in oxygenated functional groups, while organic compound oxidation rates were not significantly affected. The fluorinated electrode showed a lower ClO4− formation rate (19 ± 4 μmoles m−2 min−1) compared to the oxygenated electrode (436 ± 26 μmoles m−2 min−1) indicating the fluorinated surface limits ClO4− production. Measurement of the electrode response to the Fe(CN)63−/4− redox couple using cyclic voltammetry and electrochemical impedance spectroscopy indicated that lower ClO4− formation on the fluorinated electrode was likely a result of dipole-dipole interactions between the negatively charged F atoms and ClO3− and steric hindrance caused by the perfluorocarbon chains. This effect along with the hydrophobicity of the fluorinated electrode resulted in significantly lower ClO4− formation (96% decrease) while slightly enhancing measured oxidation rates of hydrophobic organic compounds. The use of benzoquinone as OH· probe confirmed that the fluorination process did not inhibit OH· production. The rate of benzoquinone oxidation was 2212 ± 183 μmoles m−2 min−1 on the oxygenated electrode and 2926 ± 201 μmoles m−2 min−1 on the fluorinated electrode. Density functional theory

  5. Application of a boron doped diamond (BDD) electrode as an anode for the electrolytic reduction of UO{sub 2} in Li{sub 2}O-LiCl-KCl molten salt

    Energy Technology Data Exchange (ETDEWEB)

    Park, Wooshin, E-mail: wooshin@kaeri.re.kr [Nuclear Fuel Cycle Process Development Division, Korea Atomic Energy Research Institute (KAERI), 111, 989 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Kim, Jong-Kook; Hur, Jin-Mok; Choi, Eun-Young; Im, Hun Suk; Hong, Sun-Seok [Nuclear Fuel Cycle Process Development Division, Korea Atomic Energy Research Institute (KAERI), 111, 989 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)

    2013-01-15

    A boron doped diamond thin film electrode was employed as an inert anode to replace a platinum electrode in a conventional electrolytic reduction process for UO{sub 2} reduction in Li{sub 2}O-LiCl molten salt at 650 Degree-Sign C. The molten salt was changed into Li{sub 2}O-LiCl-KCl to decrease the operation temperature to 550 Degree-Sign C at which the boron doped diamond was chemically stable. The potential for oxygen evolution on the boron doped diamond electrode was determined to be approximately 2.2 V vs. a Li-Pb reference electrode whereas that for Li deposition was around -0.58 V. The density of the anodic current was low compared to that of the cathodic current. Thus the potential of the cathode might not reach the potential for Li deposition if the surface area of the cathode is too wide compared to that of the anode. Therefore, the ratio of the surface areas of the cathode and anode should be precisely controlled. Because the reduction of UO{sub 2} is dependent on the reaction with Li, the deposition of Li is a prerequisite in the reduction process. In a consecutive reduction run, it was proved that the boron doped diamond could be employed as an inert anode.

  6. Boron-Doped Nanocrystalline Diamond Films as Functionalisation Platform for Light-Harvesting Molecular Wires

    Czech Academy of Sciences Publication Activity Database

    Yeap, W. S.; Liu, X.; Bevk, D.; Krýsová, Hana; Pasquarelli, A.; Lutsen, L.; Kavan, Ladislav; Fahlman, M.; Maes, W.; Haenen, K.

    San Francisco: Material Research Society, 2015. [2015 MRS Spring Meeting & Exhibit. Symposium F—Biohybrid Solar Cells─Photosynthesis-Based Photovoltaics and Photocatalytic Solar Cells. 06.04.2015-10.04.2015, San Francisco] Institutional support: RVO:61388955 Keywords : indium tin oxide * solar cells * electrochemistry Subject RIV: CG - Electrochemistry

  7. Dye-sensitization of boron-doped diamond foam: champion photoelectrochemical performance of diamond electrodes under solar light illumination

    Czech Academy of Sciences Publication Activity Database

    Krýsová, Hana; Kavan, Ladislav; Vlčková Živcová, Zuzana; Yeap, W. S.; Verstappen, P.; Maes, W.; Haenen, K.; Gao, F.; Nebel, C. E.

    2015-01-01

    Roč. 5, č. 99 (2015), s. 81069-81077. ISSN 2046-2069 R&D Projects: GA ČR GA13-31783S Institutional support: RVO:61388955 Keywords : dye-sensitized solar cells * electrochemistry * diamonds Subject RIV: CG - Electrochemistry Impact factor: 3.840, year: 2014

  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. 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

  10. 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.

  11. Electrolyte influence on the Cu nanoparticles electrodeposition onto boron doped diamond electrode; Influencia do eletrolito na eletrodeposicao de nanoparticulas de Cu sobre eletrodo de diamante dopado com boro

    Energy Technology Data Exchange (ETDEWEB)

    Matsushima, Jorge Tadao; Santos, Laura Camila Diniz; Couto, Andrea Boldarini; Baldan, Mauricio Ribeiro; Ferreira, Neidenei Gomes [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil)

    2012-07-01

    This paper presents the electrolyte influence on deposition and dissolution processes of Cu nanoparticles on boron doped diamond electrodes (DDB). Morphological, structural and electrochemical analysis showed BDD films with good reproducibility, quality and reversible in a specific redox system. Electrodeposition of Cu nanoparticles on DDB electrodes in three different solutions was influenced by pH and ionic strength of the electrolytic medium. Analyzing the process as function of the scan rate, it was verified a better efficiency in 0,5 mol L{sup -1} Na{sub 2}SO{sub 4} solution. Under the influence of the pH and ionic strength, Cu nanoparticles on DDB may be obtained with different morphologies and it was important for defining the desired properties. (author)

  12. 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)

  13. 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

  14. 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

  15. 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.

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

    International Nuclear Information System (INIS)

    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.

  17. 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

  18. Methanol and ethanol electro-oxidation on Pt-SnO2 and Pt-Ta2O5 sol-gel-modified boron-doped diamond surfaces

    International Nuclear Information System (INIS)

    The search for more efficient anode catalyst than platinum to be used in direct alcohol fuel cell systems is an important challenge. In this study, boron-doped diamond film surfaces were modified with Pt, Pt-SnO2 and Pt-Ta2O5 nano-crystalline deposits by the sol-gel method to study the methanol and ethanol electro-oxidation reactions in acidic medium. Electrochemical experiments carried out in steady-state conditions demonstrate that the addition of SnO2 to Pt produces a very reactive electrocatalyst that possibly adsorbs and/or dissociate ethanol more efficiently than pure Pt changing the onset potential of the reaction by 190 mV toward less positive potentials. Furthermore, the addition of Ta2O5 to Pt enhances the catalytic activity toward the methanol oxidation resulting in a negative shift of the onset potential of 170 mV. These synergic effects indicate that the addition of these co-catalysts inhibits the poisoning effect caused by strongly adsorbed intermediary species. Since the SnO2 catalyst was more efficient for ethanol oxidation, it could probably facilitate the cleavage of the C-C bond of the adsorbed intermediate fragments of the reaction.

  19. 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)

  20. 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

  1. 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.

  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. 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

  4. Photoassisted electrochemical recirculation system with boron-doped diamond anode and carbon nanotubes containing cathode for degradation of a model azo dye

    International Nuclear Information System (INIS)

    In this research work, a photoassisted electrochemical system under recirculation mode and with UV irradiation was designed for treatment of C.I. Acid Blue 92 (AB92) as a model anionic azo dye in aqueous solution. Degradation experiments were carried out with boron-doped diamond (BDD) anode and carbon nanotubes-polytetrafluoroethylene (CNTs-PTFE) cathode in the presence of sulfate as an electrolyte. A comparative study of AB92 degradation by photolysis, electrochemical oxidation and photoassisted electrochemical processes after 45 min of treatment demonstrated that degradation efficiency was 27.89, 37.65 and 95.86%, respectively. Experimental data revealed that the degradation rate of AB92 in all of the processes obeyed pseudo-first-order kinetics and application of photoassisted electrochemical system reduced electrical energy per order (EEO), considerably. Degradation efficiency of photoassisted electrochemical process enhanced by increasing applied current and flow rate values, but vice versa trend was observed for initial dye concentration and an optimum amount of 6 was obtained for initial pH. The TOC measurement results demonstrated that 93.24% of organic substrates were mineralized after 120 min of photoassisted electrochemical process and GC–Mass analysis was performed for identification of degradation intermediates

  5. 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.

  6. 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)

  7. Mineralization of salicylic acid in acidic aqueous medium by electrochemical advanced oxidation processes using platinum and boron-doped diamond as anode and cathodically generated hydrogen peroxide.

    Science.gov (United States)

    Guinea, Elena; Arias, Conchita; Cabot, Pere Lluís; Garrido, José Antonio; Rodríguez, Rosa María; Centellas, Francesc; Brillas, Enric

    2008-01-01

    Solutions containing 164 mg L(-1) salicylic acid of pH 3.0 have been degraded by electrochemical advanced oxidation processes such as anodic oxidation, anodic oxidation with electrogenerated H(2)O(2), electro-Fenton, photoelectro-Fenton and solar photoelectro-Fenton at constant current density. Their oxidation power has been comparatively studied in a one-compartment cell with a Pt or boron-doped diamond (BDD) anode and a graphite or O(2)-diffusion cathode. In the three latter procedures, 0.5mM Fe(2+) is added to the solution to form hydroxyl radical (()OH) from Fenton's reaction between Fe(2+) and H(2)O(2) generated at the O(2)-diffusion cathode. Total mineralization is attained for all methods with BDD and for photoelectro-Fenton and solar photoelectro-Fenton with Pt. The poor decontamination achieved in anodic oxidation and electro-Fenton with Pt is explained by the slow removal of most pollutants by ()OH formed from water oxidation at the Pt anode in comparison to their quick destruction with ()OH produced at BDD. ()OH generated from Fenton's reaction oxidizes rapidly all aromatic pollutants, but it cannot destroy final Fe(III)-oxalate complexes. Solar photoelectro-Fenton treatments always yield quicker degradation rate due to the very fast photodecarboxylation of these complexes by UVA irradiation supplied by solar light. The effect of current density on the degradation rate, efficiency and energy cost of all methods is examined. The salicylic acid decay always follows a pseudo-first-order kinetics. 2,3-Dihydroxybenzoic, 2,5-dihydroxybenzoic, 2,6-dihydroxybenzoic, alpha-ketoglutaric, glycolic, glyoxylic, maleic, fumaric, malic, tartronic and oxalic acids are detected as oxidation products. A general reaction sequence for salicylic acid mineralization considering all these intermediates is proposed. PMID:17692891

  8. Degradation of amaranth dye in alkaline medium by ultrasonic cavitation coupled with electrochemical oxidation using a boron-doped diamond anode

    International Nuclear Information System (INIS)

    Amaranth dye is used widely in the processing of paper, textiles, foods, cosmetics, beverages and medicines, and effluents contaminated with this compound are discharged daily into the environment. Recent studies have shown that azo dyes, especially those such as amaranth dye that have been classified as endocrine disruptors, may cause adverse effects to animal and human health. This paper describes the application of electrochemical oxidation (with a boron-doped diamond BDD thin-film anode) coupled with ultrasound sonolysis (20 kHz and 523 W cm−2) to the removal of amaranth dye from dilute alkaline solution. The electrochemical and sonoelectrochemical processes (ECh and SECh, respectively) were carried out at constant current density (10 to 50 mA cm−2) in a single compartment cylindrical cell. Sonolysis was virtually less useful for the decolorization and degradation of amaranth dye, whilst ECh and SECh were more effective in degrading the dye with almost complete removal (90 - 95%) attained after 90 min of experiment at an applied current density of 50 mA cm−2. Degradation of the dye followed pseudo first-order kinetics in both processes, but the rate of reaction was faster with the SECh treatment confirming a synergistic effect between the cavitation process and the electrochemical system. Additionally, at low applied current densities (10 and 25 mA cm−2), SECh was considerably more effective than ECh for the amaranth dye mineralization. Although at 35 and 50 mA cm−2, the two processes showed the respective removal of total organic carbon values: (i) 85% for the ECh and 90% for the SECh at 35 mA cm−2; (ii) 96% for the ECh and 98% for the SECh at 50 mA cm−2. It is concluded that SECh presented the most favorable results for the decontamination of wastewaters containing azo dye compounds

  9. 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

  10. 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

  11. Rapid and sensitive electrochemical determination of codeine in pharmaceutical formulations and human urine using a boron-doped diamond film electrode

    International Nuclear Information System (INIS)

    Highlights: ► Novel electrochemical sensor for the determination of codeine is presented. ► Codeine provided a single oxidation peak at +1.0 V vs. Ag/AgCl in BRBS at pH 7. ► Detection limit of 0.08 μM was achieved without electrode surface modification. ► Benefits of method: rapidity, low cost, low elaborateness and high repeatability. ► Possibility for drug quality control and drug analysis of biological samples. - Abstract: An unmodified boron-doped diamond film electrode was used for the first time as a sensitive and selective electrochemical sensor for the determination of codeine by the use of differential pulse voltammetry. Codeine provided a single well-defined oxidation peak at +1.0 V vs. Ag/AgCl in Britton-Robinson buffer solution at pH 7.0. Using the optimal differential pulse voltammetric conditions (modulation amplitude of 50 mV, modulation time of 40 ms and scan rate of 50 mV s−1), the detection limit of 0.08 μM, the linear response of peak current on codeine concentration in the range from 0.1 to 60 μM (R2 = 0.998, n = 6) and relative standard deviation of 0.9% at 10 μM concentration level (n = 10) were achieved without any electrode surface modification. The influence of potential interfering agents on the current response was also studied and the results indicated that the proposed method was sufficiently selective. The method was successfully applied in the determination of codeine in real samples including pharmaceutical tablets and human urine with results similar to those declared by manufacturer and obtained by reference high-performance liquid chromatography method, respectively. The typical benefits of the method may be summarized as: rapidity (20 determinations per hour), sensitivity and selectivity, low cost and elaborateness, simplicity, wide linear concentration range, low detection limit and excellent repeatability. It might also represent the competitive alternative to the existing analytical methods in monitoring of

  12. On the performances of lead dioxide and boron-doped diamond electrodes in the anodic oxidation of simulated wastewater containing the Reactive Orange 16 dye

    International Nuclear Information System (INIS)

    The performances of the Ti-Pt/β-PbO2 and boron-doped diamond (BDD) electrodes in the electrooxidation of simulated wastewaters containing 85 mg L-1 of the Reactive Orange 16 dye were investigated using a filter-press reactor. The electrolyses were carried out at the flow rate of 7 L min-1, at different current densities (10-70 mA cm-2), and in the absence or presence of chloride ions (10-70 mM NaCl). In the absence of NaCl, total decolourisation of the simulated dye wastewater was attained independently of the electrode used. However, the performance of the BDD electrode was better than that of the Ti-Pt/β-PbO2 electrode; the total decolourisations were achieved by applying only 1.0 A h L-1 and 2.0 A h L-1, respectively. In the presence of NaCl, with the electrogeneration of active chlorine, the times needed for total colour removal were markedly decreased; the addition of 50 mM Cl- or 35 mM Cl- (for Ti-Pt/β-PbO2 or BDD, respectively) to the supporting electrolyte led to a 90% decrease of these times (at 50 mA cm-2). On the other hand, total mineralization of the dye in the presence of NaCl was attained only when using the BDD electrode (for 1.0 A h L-1); for the Ti-Pt/β-PbO2 electrode, a maximum mineralization of 85% was attained (for 2.0 A h L-1). For total decolourisation of the simulated dye wastewater, the energy consumption per unit mass of dye oxidized was only 4.4 kWh kg-1 or 1.9 kWh kg-1 using the Ti-Pt/β-PbO2 or BDD electrode, respectively. Clearly the BDD electrode proved to be the best anode for the electrooxidative degradation of the dye, either in the presence or absence of chloride ions

  13. Diamond-based molecular platform for photoelectrochemistry

    Czech Academy of Sciences Publication Activity Database

    Zhong, Y.L.; Midya, A.; Ng, Z.; Chen, Z.; Daenen, M.; Nesládek, Miloš; Loh, K.P.

    2008-01-01

    Roč. 130, č. 51 (2008), s. 17218-17219. ISSN 0002-7863 Institutional research plan: CEZ:AV0Z10100520 Keywords : boron doped diamond thin film * photocurrent conversion * organic /diamond interface Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 8.091, year: 2008

  14. 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

  15. 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.

  16. Boron-doped graphene quantum dots for selective glucose sensing based on the "abnormal" aggregation-induced photoluminescence enhancement.

    Science.gov (United States)

    Zhang, Li; Zhang, Zhi-Yi; Liang, Ru-Ping; Li, Ya-Hua; Qiu, Jian-Ding

    2014-05-01

    A hydrothermal approach for the cutting of boron-doped graphene (BG) into boron-doped graphene quantum dots (BGQDs) has been proposed. Various characterizations reveal that the boron atoms have been successfully doped into graphene structures with the atomic percentage of 3.45%. The generation of boronic acid groups on the BGQDs surfaces facilitates their application as a new photoluminescence (PL) probe for label free glucose sensing. It is postulated that the reaction of the two cis-diol units in glucose with the two boronic acid groups on the BGQDs surfaces creates structurally rigid BGQDs-glucose aggregates, restricting the intramolecular rotations and thus resulting in a great boost in the PL intensity. The present unusual "aggregation-induced PL increasing" sensing process excludes any saccharide with only one cis-diol unit, as manifested by the high specificity of BGQDs for glucose over its close isomeric cousins fructose, galactose, and mannose. It is believed that the doping of boron can introduce the GQDs to a new kind of surface state and offer great scientific insights to the PL enhancement mechanism with treatment of glucose. PMID:24708154

  17. 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)

  18. 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.

  19. Piezoelectric actuated micro-resonators based on the growth of diamond on aluminum nitride thin films

    International Nuclear Information System (INIS)

    Unimorph heterostructures based on piezoelectric aluminum nitride (AlN) and diamond thin films are highly desirable for applications in micro- and nanoelectromechanical systems. In this paper, we present a new approach to combine thin conductive boron-doped as well as insulating nanocrystalline diamond (NCD) with sputtered AlN films without the need for any buffer layers between AlN and NCD or polishing steps. The zeta potentials of differently treated nanodiamond (ND) particles in aqueous colloids are adjusted to the zeta potential of AlN in water. Thereby, the nucleation density for the initial growth of diamond on AlN can be varied from very low (108 cm−2), in the case of hydrogen-treated ND seeding particles, to very high values of 1011 cm−2 for oxidized ND particles. Our approach yielding high nucleation densities allows the growth of very thin NCD films on AlN with thicknesses as low as 40 nm for applications such as microelectromechanical beam resonators. Fabricated piezo-actuated micro-resonators exhibit enhanced mechanical properties due to the incorporation of boron-doped NCD films. Highly boron-doped NCD thin films which replace the metal top electrode offer Young’s moduli of more than 1000 GPa. (paper)

  20. 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

  1. 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.

  2. 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

  3. Textured surface boron-doped ZnO transparent conductive oxides on polyethylene terephthalate substrates for Si-based thin film solar cells

    International Nuclear Information System (INIS)

    Textured surface boron-doped zinc oxide (ZnO:B) thin films were directly grown via low pressure metal organic chemical vapor deposition (LP-MOCVD) on polyethylene terephthalate (PET) flexible substrates at low temperatures and high-efficiency flexible polymer silicon (Si) based thin film solar cells were obtained. High purity diethylzinc and water vapors were used as source materials, and diborane was used as an n-type dopant gas. P-i-n silicon layers were fabricated at ∼ 398 K by plasma enhanced chemical vapor deposition. These textured surface ZnO:B thin films on PET substrates (PET/ZnO:B) exhibit rough pyramid-like morphology with high transparencies (T ∼ 80%) and excellent electrical properties (Rs ∼ 10 Ω at d ∼ 1500 nm). Finally, the PET/ZnO:B thin films were applied in flexible p-i-n type silicon thin film solar cells (device structure: PET/ZnO:B/p-i-n a-Si:H/Al) with a high conversion efficiency of 6.32% (short-circuit current density JSC = 10.62 mA/cm2, open-circuit voltage VOC = 0.93 V and fill factor = 64%).

  4. 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.

  5. 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.

  6. 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

  7. Enhanced diffusion of oxygen depending on Fermi level position in heavily boron-doped silicon

    Energy Technology Data Exchange (ETDEWEB)

    Torigoe, Kazuhisa, E-mail: ktorigoe@sumcosi.com; Fujise, Jun; Ono, Toshiaki [Technology Division, Advanced Evaluation and Technology Development Department, SUMCO Corporation, 1-52 Kubara, Yamashiro-cho, Imari, Saga 849-4256 (Japan); Nakamura, Kozo [Department of Communication Engineering, Okayama Prefectural University, 111 Kuboki, Soja, Okayama 719-1197 (Japan)

    2014-11-21

    The enhanced diffusivity of oxygen in heavily boron doped silicon was obtained by analyzing oxygen out-diffusion profile changes found at the interface between a lightly boron-doped silicon epitaxial layer and a heavily boron-doped silicon substrate by secondary ion mass spectrometry. It was found that the diffusivity is proportional to the square root of boron concentration in the range of 10{sup 18 }cm{sup −3}–10{sup 19 }cm{sup −3} at temperatures from 750 °C to 950 °C. The model based on the diffusion of oxygen dimers in double positive charge state could explain the enhanced diffusion. We have concluded that oxygen diffusion enhanced in heavily boron-doped silicon is attributed to oxygen dimers ionized depending on Fermi level position.

  8. Enhanced diffusion of oxygen depending on Fermi level position in heavily boron-doped silicon

    International Nuclear Information System (INIS)

    The enhanced diffusivity of oxygen in heavily boron doped silicon was obtained by analyzing oxygen out-diffusion profile changes found at the interface between a lightly boron-doped silicon epitaxial layer and a heavily boron-doped silicon substrate by secondary ion mass spectrometry. It was found that the diffusivity is proportional to the square root of boron concentration in the range of 1018 cm−3–1019 cm−3 at temperatures from 750 °C to 950 °C. The model based on the diffusion of oxygen dimers in double positive charge state could explain the enhanced diffusion. We have concluded that oxygen diffusion enhanced in heavily boron-doped silicon is attributed to oxygen dimers ionized depending on Fermi level position

  9. Ultrasensitive gas detection of large-area boron-doped graphene

    OpenAIRE

    Lv, Ruitao; Chen, Gugang; Li, Qing; McCreary, Amber; Botello-Méndez, Andrés; Morozov, S. V.; Liang, Liangbo; Declerck, Xavier; Perea-López, Nestor; David A. Cullen; Feng, Simin; Elías, Ana Laura; Cruz-Silva, Rodolfo; Fujisawa, Kazunori; Endo, Morinobu

    2015-01-01

    The gas-sensing performance of graphene could be remarkably enhanced by incorporating dopants into its lattice based on theoretical calculations. However, to date, experimental progress on boron-doped graphene (BG) is still very scarce. Here, we achieved the controlled growth of large-area, high-crystallinity BG sheets and shed light on their electronic features associated with boron dopants at the atomic scale. As a proof-of-concept, it is demonstrated that boron doping in graphene could lea...

  10. 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.

  11. Diamond-based electrodes for organic photovoltaic devices

    Czech Academy of Sciences Publication Activity Database

    Kovalenko, Alexander; Ashcheulov, Petr; Guerrero, A.; Heinrichová, P.; Fekete, Ladislav; Vala, M.; Weiter, M.; Kratochvílová, Irena; Garcia-Belmonte, G.

    2015-01-01

    Roč. 134, Mar (2015), s. 73-79. ISSN 0927-0248 R&D Projects: GA TA ČR TA04020156 Institutional support: RVO:68378271 Keywords : organic photovoltaics * boron doped diamond * chemical vapor deposition Subject RIV: JI - Composite Materials Impact factor: 5.337, year: 2014

  12. 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

  13. Design and fabrication of piezoresistive strain gauges based on nanocrystalline diamond layers

    Czech Academy of Sciences Publication Activity Database

    Kulha, P.; Kromka, Alexander; Babchenko, Oleg; Husák, M.; Haenen, K.

    Brno: Tribun EU s.r.o., 2010 - (Vesely, M.; Vincze, A.; Vavra, I.). s. 138 ISBN 978-80-7399-969-8. [Joint Vacuum Conference /13./. 20.06.2010-24.06.2010, Strbske Pleso] Institutional research plan: CEZ:AV0Z10100521 Keywords : piezo-resistive strain sensor * lithography * boron-doped diamond Subject RIV: BM - Solid Matter Physics ; Magnetism

  14. 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。

  15. 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

  16. 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-.

  17. 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

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

    International Nuclear Information System (INIS)

    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-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 (B4C), 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 ∼310 mA h g-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.

  19. 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.

  20. Boron-doped MnO2/carbon fiber composite electrode for supercapacitor

    International Nuclear Information System (INIS)

    Highlights: • Interstitial ion in MnO2 lattice. • Porous film composed by interlocking worm-like nanostructure. • Boron-doped birnessite-type MnO2/carbon fiber composite electrode. • Enhanced capacitive properties through nonmetal element doping. - Abstract: The boron-doped MnO2/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 MnO2 crystal and the formation of worm-like nanostructure. Based on the analysis of binding energy, element boron incorporates into the MnO2 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 MnO2 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 Mn2+ and the absence of active site on the outer surface

  1. 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.

  2. 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.

  3. Effect of boron doping on the rectification effect and photovoltaic performance of CdS/Si heterostructure based on Si nanoporous pillar array

    International Nuclear Information System (INIS)

    A series of CdS/Si heterostructures were prepared through growing B-doped CdS thin films on silicon nanoporous pillar array (Si-NPA) by a chemical bath deposition (CBD) method. The experimental data show that B-doping concentration of CdS thin films could be tuned effectively through controlling the mole ratio of [B]/[Cd] of the initial CBD solution without causing obvious variation of the crystal phase and surface morphology of CdS/Si-NPA. Both the electrical rectification and photovoltaic parameters of CdS/Si-NPA show strong dependence upon B-doping concentration, and the optimal characteristics are achieved for the samples prepared with [B]/[Cd] = 0.01. Compared with CdS/Si-NPA solar cells without B-doping, an increment over 300 times for energy conversion efficiency is realized. The mechanism for the efficiency increment is analyzed based on the effect of B-doping on the band structure of CdS/Si-NPA. These results indicate that B-doping might be an effective path for promoting the device performance of solar cells based on CdS/Si-NPA. (paper)

  4. Diamond based photonic crystal microcavities.

    Science.gov (United States)

    Tomljenovic-Hanic, S; Steel, M J; de Sterke, C Martijn; Salzman, J

    2006-04-17

    Diamond based technologies offer a material platform for the implementation of qubits for quantum computing. The photonic crystal architecture provides the route for a scalable and controllable implementation of high quality factor (Q) nanocavities, operating in the strong coupling regime for cavity quantum electrodynamics. Here we compute the photonic band structures and quality factors of microcavities in photonic crystal slabs in diamond, and compare the results with those of the more commonly-used silicon platform. We find that, in spite of the lower index contrast, diamond based photonic crystal microcavities can exhibit quality factors of Q=3.0x10(4), sufficient for proof of principle demonstrations in the quantum regime. PMID:19516502

  5. 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.

  6. High-pressure high-temperature phase diagram of gadolinium studied using a boron-doped heater anvil

    Science.gov (United States)

    Montgomery, J. M.; Samudrala, G. K.; Velisavljevic, N.; Vohra, Y. K.

    2016-04-01

    A boron-doped designer heater anvil is used in conjunction with powder x-ray diffraction to collect structural information on a sample of quasi-hydrostatically loaded gadolinium metal up to pressures above 8 GPa and 600 K. The heater anvil consists of a natural diamond anvil that has been surface modified with a homoepitaxially grown chemical-vapor-deposited layer of conducting boron-doped diamond, and is used as a DC heating element. Internally insulating both diamond anvils with sapphire support seats allows for heating and cooling of the high-pressure area on the order of a few tens of seconds. This device is then used to scan the phase diagram of the sample by oscillating the temperature while continuously increasing the externally applied pressure and collecting in situ time-resolved powder diffraction images. In the pressure-temperature range covered in this experiment, the gadolinium sample is observed in its hcp, αSm, and dhcp phases. Under this temperature cycling, the hcp → αSm transition proceeds in discontinuous steps at points along the expected phase boundary. From these measurements (representing only one hour of synchrotron x-ray collection time), a single-experiment equation of state and phase diagram of each phase of gadolinium is presented for the range of 0-10 GPa and 300-650 K.

  7. 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.

  8. Boron-doped nanocrystalline diamond electrodes for neural interfaces

    DEFF Research Database (Denmark)

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

    2016-01-01

    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...

  9. 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.

  10. 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 .

  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. 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

    2016-01-01

    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. PMID:27109361

  14. 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.

  15. Ultrasensitive gas detection of large-area boron-doped graphene

    Science.gov (United States)

    Lv, Ruitao; Chen, Gugang; Li, Qing; McCreary, Amber; Botello-Méndez, Andrés; Morozov, S. V.; Declerck, Xavier; Perea-López, Nestor; Cullen, David A.; Feng, Simin; Elías, Ana Laura; Cruz-Silva, Rodolfo; Fujisawa, Kazunori; Endo, Morinobu; Kang, Feiyu; Charlier, Jean-Christophe; Meunier, Vincent; Pan, Minghu; Harutyunyan, Avetik R.; Novoselov, Konstantin S.; Terrones, Mauricio

    2015-01-01

    Heteroatom doping is an efficient way to modify the chemical and electronic properties of graphene. In particular, boron doping is expected to induce a p-type (boron)-conducting behavior to pristine (nondoped) graphene, which could lead to diverse applications. However, the experimental progress on atomic scale visualization and sensing properties of large-area boron-doped graphene (BG) sheets is still very scarce. This work describes the controlled growth of centimeter size, high-crystallinity BG sheets. Scanning tunneling microscopy and spectroscopy are used to visualize the atomic structure and the local density of states around boron dopants. It is confirmed that BG behaves as a p-type conductor and a unique croissant-like feature is frequently observed within the BG lattice, which is caused by the presence of boron-carbon trimers embedded within the hexagonal lattice. More interestingly, it is demonstrated for the first time that BG exhibits unique sensing capabilities when detecting toxic gases, such as NO2 and NH3, being able to detect extremely low concentrations (e.g., parts per trillion, parts per billion). This work envisions that other attractive applications could now be explored based on as-synthesized BG. PMID:26575621

  16. Influence of boron doped carbon nanotubes on electric and electromagnetic properties of phosphate composite materials

    International Nuclear Information System (INIS)

    The work presents a study of the possibility to develop the multifunctional composite materials based on the electromagnetically absorbing nonfired, mechanically strong and heat-resistant phosphate ceramics. The potentialities of using pure and boron doped multiwalled carbon nanotubes (MWCNTs and B-MWCNTs, respectively) as functional additives to the phosphate matrix were investigated. It was found that a length of MWCNT is the determining factor for the electrical conductivity and high-frequency conductivity of the composite. Growth of the intrinsic conductivity of boron-containing MWCNTs, compared to their undoped counterparts, has no significant influence on the possible resistance decrease of the composite on their basis in the static mode and also on its ability to electromagnetic shielding. This is due to a small length of B-MWCNTs and hence much greater concentrations required to achieve the percolation threshold than those studied (up to 1,5 wt. %). On the contrary, the use of long pure MWCNTs in small concentrations has a tremendous impact on the electromagnetic properties of the phosphate composite: on introduction of 1,5 wt. % of MWCNTs one can observe increase in the conductivity by 13 orders of magnitude, and the composite MWCNTs/phosphate 1 mm thick is opaque to microwave radiation. Taking into account the interest in using the boron-doped MWNT also as neutron-absorbing materials, it is essential to improve the synthesis methods of B-MWCNTs with the aim of increasing their length. (authors)

  17. Meissner effect in films of ropes of boron-doped single-walled carbon nanotubes; Correlation with applied pressure and boron-doped multi-walled nanotubes

    International Nuclear Information System (INIS)

    Superconductivity in carbon nanotubes (CNTs) is attracting considerable attention. Recently, we have reported successful boron doping into single-walled CNTs (SWNTs) and also revealed its correlation with superconductivity. In the present study, we report results of pressure-applied magnetization measurements in films consisting of ropes of boron-doped SWNTs. It reveals that Tc and magnitude for Meissner effect is mostly independent of applied pressure, while magnitude of graphite diamagnetism drastically increases as pressure increases. We also report result of resistance measurements in the samples and also correlation of boron doped SWNTs with multi-walled CNTs, in which we reported superconductivity previously.

  18. Thick porous electrochemical diamond electrodes: novel fabrication method and properties

    Czech Academy of Sciences Publication Activity Database

    Petrák, V.; Vlčková Živcová, Zuzana; Krýsová, Hana; Frank, Otakar; Zukal, Arnošt; Klimša, Ladislav; Kopeček, Jaromír; Taylor, A.; Kavan, Ladislav; Mortet, Vincent

    Hasselt: The Hasselt Diamond Workshop Committees, 201 6. Č. 146, 153. [Hasselt Diamond Workshop 2016. SBDD XXI. 09.03.2016-11.03.2016, Hasselt] R&D Projects: GA ČR GA13-31783S Institutional support: RVO:61388955 ; RVO:68378271 Keywords : electrochemistry * boron-doped diamond * electrodes Subject RIV: CG - Electrochemistry

  19. Technology for diamond based electronics

    OpenAIRE

    Kubovic, Michal

    2009-01-01

    The superior electrical and thermal properties of diamond predestine this material to become an important semiconductor. In this thesis, diamond field effect transistors and diodes were fabricated and evaluated. The progress in fabrication technology enabled DC, small and large signal measurements on FETs employing a hydrogen-induced p-type channel. Operation of such FETs at microwave frequencies showed high cut-off frequencies and first power measurements on diamond FETs have been performed ...

  20. 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

  1. Modeling and simulation of boron-doped nanocrystalline silicon carbide thin film by a field theory.

    Science.gov (United States)

    Xiong, Liming; Chen, Youping; Lee, James D

    2009-02-01

    This paper presents the application of a multiscale field theory in modeling and simulation of boron-doped nanocrystalline silicon carbide (B-SiC). The multiscale field theory was briefly introduced. Based on the field theory, numerical simulations show that intergranular glassy amorphous films (IGFs) and nano-sized pores exist in triple junctions of the grains for nanocrystalline B-SiC. Residual tensile stress in the SiC grains and compressive stress on the grain boundaries (GBs) were observed. Under tensile loading, it has been found that mechanical response of 5 wt% boron-SiC exhibits five characteristic regimes. Deformation mechanism at atomic scale has been revealed. Tensile strength and Young's modulus of nanocrystalline SiC were accurately reproduced. PMID:19441448

  2. 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.

  3. 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

  4. 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

  5. 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

  6. Effect of boron concentration on physicochemical properties of boron-doped carbon nanotubes

    International Nuclear Information System (INIS)

    Boron-doped carbon nanotubes (B-CNTs) were synthesized using chemical vapour deposition (CVD) floating catalyst method. Toluene was used as the carbon source, triphenylborane as boron as well as the carbon source while ferrocene was used as the catalyst. The amount of triphenylborane used was varied in a solution of toluene and ferrocene. Ferrocene was kept constant at 2.5 wt.%. while a maximum temperature of 900 °C was used for the synthesis of the shaped carbon nanomaterial (SCNMs). SCNMs obtained were characterized by the use of transmission electron microscope (TEM), scanning electron microscope (SEM), high resolution-electron microscope, electron dispersive X-ay spectroscopy (EDX), Raman spectroscopy, inductively coupled plasma-optical emission spectroscopy (ICP-OES), vibrating sample magnetometer (VSM), nitrogen adsorption at 77 K, and inverse gas chromatography. TEM and SEM analysis confirmed SCNMs obtained were a mixture of B-CNTs and carbon nanofibres (B-CNF). EDX and ICP-OES results showed that boron was successively incorporated into the carbon hexagonal network of CNTs and its concentration was dependent on the amount of triphenylborane used. From the VSM results, the boron doping within the CNTs introduced ferromagnetic properties, and as the percentage of boron increased the magnetic coactivity and squareness changed. In addition, boron doping changed the conductivity and the surface energy among other physicochemical properties of B-CNTs. - Highlights: • Boron-doping of carbon nanotubes (CNTs) changes their physiochemical properties. • Amount of boron-doping was dependent on the wt.% of boron precursor used. • Boron-doping changed CNTs surfaces and the distribution of dispersive energy sites. • Boron-doping affected the conductivity and ferromagnetic properties. • Increased boron-doping results in a more favourable interaction with polar probes

  7. Effect of boron-doping on thermoelectric properties of rutile-type titanium dioxide sintered materials

    International Nuclear Information System (INIS)

    Research highlights: → Boron-doped rutile-type TiO2 was prepared by pulsed current sintering method. → The B and TiB2 addition was effective for boron-doping of RTO. → Both electrical resistivity and thermal conductivity decreased using B or TiB2 as a additive. The thermoelectric figure of merit was enhanced by boron-doping. - Abstract: The electrical and thermal transport properties of boron-doped rutile-type TiO2 were investigated. The rutile-type TiO2 powder was mixed with B2O3, TiB2 or B and the mixtures were sintered using the pulse current sintering method at 1473 K. Secondary ion mass spectroscopy (SIMS) and X-ray diffraction (XRD) measurements showed that B or TiB2 addition was effective for boron-doping. The boron was well distributed in the sintered materials and the unit cell volume of rutile increased as the amounts of added B or TiB2 increased. The electrical resistivity and Seebeck coefficient at 300 K decreased with an increase in the unit cell volume indicating that boron addition leads to an increase in the electron concentration. Thermal conductivity at room temperature also decreased with an increase in unit cell volume and as a result the thermoelectric figure of merit for rutile-type TiO2 was enhanced by boron-doping.

  8. 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.

  9. 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.

  10. Properties of boron-doped thin films of polycrystalline silicon

    Energy Technology Data Exchange (ETDEWEB)

    Merabet, Souad [Electronic Department, Faculty of Science and Technology, University of Jijel, Cité Ouled-Aissa B. P. 98 Jijel, 18 000 Jijel (Algeria)

    2013-12-16

    The properties of polycrystalline-silicon films deposited by low pressure chemical vapor deposition and doped heavily in situ boron-doped with concentration level of around 2×10{sup 20}cm{sup −3} has been studied. Their properties are analyzed using electrical and structural characterization means by four points probe resistivity measurements and X-ray diffraction spectra. The thermal-oxidation process are performed on sub-micron layers of 200nm/c-Si and 200nm/SiO{sub 2} deposited at temperatures T{sub d} ranged between 520°C and 605°C and thermally-oxidized in dry oxygen ambient at 945°C. Compared to the as-grown resistivity with silicon wafers is known to be in the following sequence <ρ{sub 200nm/c−Si}> < <ρ{sub 200nm/SiO2}> and <ρ{sub 520}> < <ρ{sub 605}>. The measure X-ray spectra is shown, that the Bragg peaks are marked according to the crystal orientation in the film deposited on bare substrates (poly/c-Si), for the second series of films deposited on bare oxidized substrates (poly/SiO{sub 2}) are clearly different.

  11. Properties of boron-doped thin films of polycrystalline silicon

    International Nuclear Information System (INIS)

    The properties of polycrystalline-silicon films deposited by low pressure chemical vapor deposition and doped heavily in situ boron-doped with concentration level of around 2×1020cm−3 has been studied. Their properties are analyzed using electrical and structural characterization means by four points probe resistivity measurements and X-ray diffraction spectra. The thermal-oxidation process are performed on sub-micron layers of 200nm/c-Si and 200nm/SiO2 deposited at temperatures Td ranged between 520°C and 605°C and thermally-oxidized in dry oxygen ambient at 945°C. Compared to the as-grown resistivity with silicon wafers is known to be in the following sequence 200nm/c−Si> 200nm/SiO2> and 520> 605>. The measure X-ray spectra is shown, that the Bragg peaks are marked according to the crystal orientation in the film deposited on bare substrates (poly/c-Si), for the second series of films deposited on bare oxidized substrates (poly/SiO2) are clearly different

  12. 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

  13. Improved electrochemical performance of boron-doped SiO negative electrode materials in lithium-ion batteries

    Science.gov (United States)

    Woo, Jihoon; Baek, Seong-Ho; Park, Jung-Soo; Jeong, Young-Min; Kim, Jae Hyun

    2015-12-01

    We introduce a one-step process that consists of thermal disproportionation and impurity doping to enhance the reversible capacity and electrical conductivity of silicon monoxide (SiO)-based negative electrode materials in Li-ion batteries. Transmission electron microscope (TEM) results reveal that thermally treated SiO at 900 °C (H-SiO) consists of uniformly dispersed nano-crystalline Si (nc-Si) in an amorphous silicon oxide (SiOx) matrix. Compared to that of prinstine SiO, the electrochemical performance of H-SiO shows improved specific capacity, due mainly to the increased reversible capacity by nc-Si and to the reduced volume expansion by thermally disproportionated SiOx matrix. Further electrochemical improvements can be obtained by boron-doping on SiO (HB-SiO) using solution dopant during thermal disproportionation. HB-SiO electrode without carbon coating exhibits significantly enhanced specific capacity superior to that of undoped H-SiO electrode, having 947 mAh g-1 at 0.5C rate and excellent capacity retention of 93.3% over 100 cycles. Electrochemical impedance spectroscopy (EIS) measurement reveals that the internal resistance of the HB-SiO electrode is significantly reduced by boron doping.

  14. Structure and electrochemical applications of boron-doped graphitized carbon nanofibers

    Science.gov (United States)

    Yeo, Jae-Seong; Jang, Sang-Min; Miyawaki, Jin; An, Bai; Mochida, Isao; Rhee, Choong Kyun; Yoon, Seong-Ho

    2012-08-01

    Boron-doped graphitized carbon nanofibers (CNFs) were prepared by optimizing CNFs preparation, surface treatment, graphitization and boron-added graphitization. The interlayer spacing (d002) of the boron-doped graphitized CNFs reached 3.356 Å, similar to that of single-crystal graphite. Special platelet CNFs (PCNFs), for which d002 is less than 3.400 Å, were selected for further heat treatment. The first heat treatment of PCNFs at 2800 °C yielded a d002 between 3.357 and 3.365 Å. Successive nitric acid treatment and a second heat treatment with boric acid reduced d002 to 3.356 Å. The resulting boron-doped PCNFs exhibited a high discharge capacity of 338 mAh g-1 between 0 and 0.5 V versus Li/Li+ and 368 mAh g-1 between 0 and 1.5 V versus Li/Li+. The first-cycle Coulombic efficiency was also enhanced to 71-80%. Such capacity is comparable to that of natural graphite under the same charge/discharge conditions. The boron-doped PCNFs also exhibited improved rate performance with twice the capacity of boron-doped natural graphite at a discharge rate of 5 C.

  15. Structure and electrochemical applications of boron-doped graphitized carbon nanofibers

    International Nuclear Information System (INIS)

    Boron-doped graphitized carbon nanofibers (CNFs) were prepared by optimizing CNFs preparation, surface treatment, graphitization and boron-added graphitization. The interlayer spacing (d002) of the boron-doped graphitized CNFs reached 3.356 Å, similar to that of single-crystal graphite. Special platelet CNFs (PCNFs), for which d002 is less than 3.400 Å, were selected for further heat treatment. The first heat treatment of PCNFs at 2800 °C yielded a d002 between 3.357 and 3.365 Å. Successive nitric acid treatment and a second heat treatment with boric acid reduced d002 to 3.356 Å. The resulting boron-doped PCNFs exhibited a high discharge capacity of 338 mAh g−1 between 0 and 0.5 V versus Li/Li+ and 368 mAh g−1 between 0 and 1.5 V versus Li/Li+. The first-cycle Coulombic efficiency was also enhanced to 71–80%. Such capacity is comparable to that of natural graphite under the same charge/discharge conditions. The boron-doped PCNFs also exhibited improved rate performance with twice the capacity of boron-doped natural graphite at a discharge rate of 5 C. (paper)

  16. Critical components for diamond-based quantum coherent devices

    International Nuclear Information System (INIS)

    The necessary elements for practical devices exploiting quantum coherence in diamond materials are summarized, and progress towards their realization documented. A brief review of future prospects for diamond-based devices is also provided

  17. Diamond-based single-photon emitters

    International Nuclear Information System (INIS)

    The exploitation of emerging quantum technologies requires efficient fabrication of key building blocks. Sources of single photons are extremely important across many applications as they can serve as vectors for quantum information-thereby allowing long-range (perhaps even global-scale) quantum states to be made and manipulated for tasks such as quantum communication or distributed quantum computation. At the single-emitter level, quantum sources also afford new possibilities in terms of nanoscopy and bio-marking. Color centers in diamond are prominent candidates to generate and manipulate quantum states of light, as they are a photostable solid-state source of single photons at room temperature. In this review, we discuss the state of the art of diamond-based single-photon emitters and highlight their fabrication methodologies. We present the experimental techniques used to characterize the quantum emitters and discuss their photophysical properties. We outline a number of applications including quantum key distribution, bio-marking and sub-diffraction imaging, where diamond-based single emitters are playing a crucial role. We conclude with a discussion of the main challenges and perspectives for employing diamond emitters in quantum information processing.

  18. Energy-band diagram configuration of Al2O3/oxygen-terminated p-diamond metal-oxide-semiconductor

    Science.gov (United States)

    Maréchal, A.; Aoukar, M.; Vallée, C.; Rivière, C.; Eon, D.; Pernot, J.; Gheeraert, E.

    2015-10-01

    Diamond metal-oxide-semiconductor capacitors were prepared using atomic layer deposition at 250 °C of Al2O3 on oxygen-terminated boron doped (001) diamond. Their electrical properties were investigated in terms of capacitance and current versus voltage measurements. Performing X-ray photoelectron spectroscopy based on the measured core level energies and valence band maxima, the interfacial energy band diagram configuration of the Al2O3/O-diamond is established. The band diagram alignment is concluded to be of type I with valence band offset Δ E v of 1.34 ± 0.2 eV and conduction band offset Δ E c of 0.56 ± 0.2 eV considering an Al2O3 energy band gap of 7.4 eV. The agreement with electrical measurement and the ability to perform a MOS transistor are discussed.

  19. 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.

  20. Application and film characterization of boron-doped PECVD TEOS for intermetal dielectric

    International Nuclear Information System (INIS)

    An interlayer dielectric (ILD) appropriate for multilevel wiring in submicron geometries has been developed based on TEOS chemistry. The application of a boron-doped plasma CVD TEOS (BSG) has proven to be capable of filling gaps with the aspect ratio up to 1:5:1. The film properties of BSG are studied as a function of process variables. Various analytical tools were employed in film characterization, consisting of : FTIR, for boron incorporation and moisture pick-up sensitivity; stress measurements as a function of time and temperature (hysteresis); wet etch rate in HF acid as an indirect measure of film density; thin film breakdown voltage (BVG) integrity. The dehydration cycle applied to different films indicates the presence of more moisture in the film deposited at lower RF powers. The C-V study of thin oxides (800-1000 A degrees) shows the existence of large trapped negative charges in the oxide leading to positive flatband voltage shift (5 volts). The device electrical characteristics and film's physical properties are correlated

  1. 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

  2. Highly conductive boron doped micro/nanocrystalline silicon thin films deposited by VHF-PECVD for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Juneja, Sucheta; Sudhakar, S., E-mail: sudhakars@nplindia.org; Gope, Jhuma; Lodhi, Kalpana; Sharma, Mansi; Kumar, Sushil

    2015-09-15

    Graphical abstract: AFM images of boron doped micro/nanocrystalline silicon films at different diborane gas flow. - Highlights: • High deposition rate of 10 Å/s was achieved for boron doped silicon films. • Wide range of optical band gap from 1.32 eV to 1.84 eV observed for the deposited films. - Abstract: Boron doped hydrogenated micro/nanocrystalline silicon (μc/nc-Si:H) thin films have been deposited by plasma enhanced chemical vapor deposition technique (PECVD) using silane (SiH{sub 4}) diluted in argon. Diborane (B{sub 2}H{sub 6}) was used as the dopant gas and deposition was carried out at substrate temperature of 200 °C. The diborane flow (F{sub B}) varied in the range 0.00–0.30. Here, we report the effects of B{sub 2}H{sub 6} doping on electronic, optical and structural properties of hydrogenated micro/nanocrystalline silicon films. The structural properties were analyzed by atomic force microscopy (AFM) and X-ray diffraction (XRD). The doped micro/nano crystalline silicon films presented a crystallographic orientation preferentially in the (1 1 1) and (2 2 0) plane. We resolve the deposition parameters that lead to the formation of p-type micro/nanocrystalline silicon thin films with very high value of conductivity and lower optical band gap. Correlations between structural and electrical properties were also studied. Based on temperature dependent conductivity measurements, it has been observed that the room temperature dark conductivity varies in the range 1.45 × 10{sup −4} Ω{sup −1} cm{sup −1} to 2.02 Ω{sup −1} cm{sup −1} for the B-doped films. Meanwhile, the corresponding value of activation energies decreased to 0.06 eV for the B-doped films, which indicates the doped μc/nc-Si films with high conductivity can be achieved and these films prove to be a very good candidate for application in amorphous and micro/nano crystalline silicon solar cells as a p-type window layer.

  3. 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.

  4. 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.

  5. 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...

  6. 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)

  7. 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.

  8. 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

  9. 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.

  10. Pyrolytic synthesis of boron-doped graphene and its application as electrode material for supercapacitors

    International Nuclear Information System (INIS)

    Highlights: • Boron-doped graphene was prepared by pyrolysis of graphene oxide with boric acid at 900 °C under an argon atmosphere. • The boron doping content reached the highest value of 4.7% after 3 h of pyrolysis at 900 °C. • The BG-900-3h electrode exhibited the highest specific capacitance of 172.5 F g−1 at 0.5 A g−1 and maintained 96.5% of initial capacity after a continuous of 5000 times cycling. -- Abstract: Chemical doping with foreign atoms is an effective approach to intrinsically modify the properties of the carbon materials. Herein, boron-doped graphene (BG) was prepared through pyrolysis of graphene oxide (GO) with boric acid (H3BO3) in an argon atmosphere at 900 °C. Both boron-doping and reduction of GO to graphene were simultaneously achieved under the thermal treatment processing. Namely, at high temperature condition, H3BO3 was converted into boron oxide (B2O3) accompanied by diffusing B2O3 vapor into the graphene nanosheets, then boron atoms can replace the carbon atoms inside the graphene layers and thereby substitutionally doped into the graphene lattice. The boron content in BG increased with prolonging the reaction time and reached the highest value of 4.7% after 3 h of pyrolysis, which in turn affected their electrochemical properties. The as-prepared electrode of BG-900-3h exhibits the highest capacitive behavior (172.5 F g−1, 0.5 A g−1) and superior cycling stability (maintaining 96.5% of initial capacity after 5000 times of cycling). Remarkably, the boron-doping increased the capacitance of BG-900-3h by about 80% compared to pristine graphene. These results imply that the doping of boron into graphene lattice induces remarkable performance enhancement, and thus make the doped materials superior to those of pristine graphene as electrode materials for supercapacitors

  11. Fabrication of Diamond Based Sensors for Use in Extreme Environments

    Directory of Open Access Journals (Sweden)

    Gopi K. Samudrala

    2015-04-01

    Full Text Available Electrical and magnetic sensors can be lithographically fabricated on top of diamond substrates and encapsulated in a protective layer of chemical vapor deposited single crystalline diamond. This process when carried out on single crystal diamond anvils employed in high pressure research is termed as designer diamond anvil fabrication. These designer diamond anvils allow researchers to study electrical and magnetic properties of materials under extreme conditions without any possibility of damaging the sensing elements. We describe a novel method for the fabrication of designer diamond anvils with the use of maskless lithography and chemical vapor deposition in this paper. This method can be utilized to produce diamond based sensors which can function in extreme environments of high pressures, high and low temperatures, corrosive and high radiation conditions. We demonstrate applicability of these diamonds under extreme environments by performing electrical resistance measurements during superconducting transition in rare earth doped iron-based compounds under high pressures to 12 GPa and low temperatures to 10 K.

  12. Anodic oxidation with doped diamond electrodes: a new advanced oxidation process

    International Nuclear Information System (INIS)

    Boron-doped diamond anodes allow to directly produce OH· radicals from water electrolysis with very high current efficiencies. This has been explained by the very high overvoltage for oxygen production and many other anodic electrode processes on diamond anodes. Additionally, the boron-doped diamond electrodes exhibit a high mechanical and chemical stability. Anodic oxidation with diamond anodes is a new advanced oxidation process (AOP) with many advantages compared to other known chemical and photochemical AOPs. The present work reports on the use of diamond anodes for the chemical oxygen demand (COD) removal from several industrial wastewaters and from two synthetic wastewaters with malic acid and ethylenediaminetetraacetic (EDTA) acid. Current efficiencies for the COD removal between 85 and 100% have been found. The formation and subsequent removal of by-products of the COD oxidation has been investigated for the first time. Economical considerations of this new AOP are included

  13. Electrochemical treatment of reverse osmosis concentrate on boron-doped electrodes in undivided and divided cell configurations

    International Nuclear Information System (INIS)

    Highlights: • 100% of COD and ∼70% of DOC was removed in both cell configurations. • ∼21.7 mg L−1 of AOCl and ∼2.3 mg L−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−1, and generally remaining near the initial baseline-toxicity equivalent concentration (TEQ) of the raw concentrate (i.e., ∼2 mg L−1). The exception was a high range toxicity measure in the undivided cell (i.e., TEQ = 11 mg L−1 at 2.4 Ah L−1), which rapidly decreased to 4 mg L−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−1 and 0.34 kWh gCOD−1, respectively, yet it did not demonstrate any improvement regarding by-products formation

  14. 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.

  15. 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.

  16. Thermodynamic and kinetic study on interfacial reaction and diamond graphitization of Cu-Fe-based diamond composite

    Institute of Scientific and Technical Information of China (English)

    Li Wen-Sheng; Zhang Jie; Dong Hong-Feng; Chu Ke; Wang Shun-Cai; Liu Yi; Li Ya-Ming

    2013-01-01

    Cu-Fe based diamond composites used for saw-blade segments are directly fabricated by vacuum and pressureassisted sintering.The carbide forming elements Cr and Ti are added to improve interfacial bonding between diamond and the Cu-Fe matrix.The interfacial reactions between diamond/graphite and Cr or Ti,and diamond graphitization are investigated by thermodynamics/kinetics analyses and experimental methods.The results show that interfacial reactions and graphitization of diamond can automatically proceed thermodynamically.The Cr3C2,Cr7C3,Cr23C6,and TiC are formed at the interfaces of composites by reactions between diamond and Cr or Ti; diamond graphitization does not occur because of the kinetic difficulty at 1093 K under the pressure of 13 MPa.

  17. 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.

  18. 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

  19. Electrochemical oxidation of phenol at boron-doped diamond electrode in pulse current mode

    International Nuclear Information System (INIS)

    Highlights: → A pulse current supply was first conducted to the BDD anode system to minimize the energy consumption. → A response surface methodology (RSM) was introduced to investigate the influence the operative parameters on the performance of the pulse-BDD anode system. → By the comparison with constant current mode, we evaluated the superiority of pulse current mode in energy saving and discussed the mechansim. - Abstract: In this study, a pulse current supply was initially used in a BDD anode system (pulse-BDD anode system) for electrochemical oxidation of phenol. The influences of operative parameters (current density, retention time, pulse duty cycle, power frequency) on the system performances were exmamined by response surface methodology (RSM). As for COD degradation efficiency (DCOD) and specific energy consumption (Es), the influence of retention time was more important than current density and pulse duty cycle, while power frequency hardly presented significant influence. By the comparison with constant current mode, an obvious specific energy consumption reduction was achieved in the pulse-BDD anode system, though the DCOD was slightly lower. The significant Es decrease might be attributed to the reduction of side reactions and concentration polarization in pulse current mode. The pulse-BDD anode system demonstrated an efficient technology to simultaneously obtain high pollutant degradation efficiency and low energy consumption.

  20. 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...

  1. 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.

  2. Density functional theory prediction for diffusion of lithium on boron-doped graphene surface

    International Nuclear Information System (INIS)

    The density functional theory (DFT) investigation shows that graphene has changed from semimetal to semiconductor with the increasing number of doped boron atoms. Lithium and boron atoms acted as charge contributors and recipients, which attracted to each other. Further investigations show that, the potential barrier for lithium diffusion on boron-doped graphene is higher than that of intrinsic graphene. The potential barrier is up to 0.22 eV when six boron atoms doped (B6C26), which is the lowest potential barrier in all the doped graphene. The potential barrier is dramatically affected by the surface structure of graphene.

  3. Porous structure variation of boron-doped graphite during neutron irradiation

    International Nuclear Information System (INIS)

    Dynamics of porous structure variation of graphite during neutron irradiation was studied with the use of recrystallized boron-doped graphite as model material. It was shown that specific volume of open pores grew but density of RG-B graphite decreased at low temperature irradiation (320-340 K). Thermal annealing at 2100 K of irradiated samples partially reduces their elongation and leads to additional increase of volume of open pores. Linear relation (in semilogarithmic coordinates) of decrease of coefficient of elasticity with growth of volume of open pores was established for irradiated and annealed samples

  4. PECVD diamond-based high performance power diodes

    OpenAIRE

    Gürbüz, Yaşar; Gurbuz, Yasar; Kang, Weng Poo; Davidson, Jimmy L.; Kerns, David V.; Zhou, Q.

    2005-01-01

    In this study, we have designed, fabricated, characterized, and analyzed plasma-enhanced chemical vapor deposition (PECVD) diamond-based Schottky diodes for high power electronics applications. We have elaborated four critical issues in the synthetic-diamond semiconductor technology: 1) growth, 2) doping, 3) Schottky contact, and 4) different device structures in order to achieve better performance parameters. We have obtained 500 V of breakdown voltage on one device and 100 A/cm/sup 2/ of cu...

  5. Particle and radiation detectors based on diamond

    Energy Technology Data Exchange (ETDEWEB)

    Bergonzo, P.; Tromson, D.; Mer, C.; Guizard, B.; Foulon, F.; Brambilla, A. [LIST/DIMRI/SIAR, CEA/Saclay, Gif-sur-Yvette (France)

    2001-05-16

    CVD diamond is a remarkable material for the fabrication of particle and photon radiation detectors. The improvement of the electronic properties of the material has been under intensive investigations and led to the development of a few applications that are addressing specific industrial needs. In particular, we have used diamond layers for industrial applications where it exhibits attractive characteristics as compared with other materials: e.g., radiation and corrosion hardness for {alpha}-counters or high gamma-meters at high fluxes; high transparency to low energy X-rays for synchrotron beam line monitoring devices, etc. These specific properties can motivate the use of diamond even though the detection properties remain relatively poor. Indeed, one inherent problem with diamond is the presence of defect levels that are altering the detection characteristics. These are observed in all CVD materials but also in very high quality natural diamonds. They result in unstable responses and carrier losses. Also, it has been observed that high sensitivities may result from the progressive filling of deep levels, e.g. pumping effects, with a detrimental effect on the stability and the response time. Also, the polycrystalline nature is somewhat detrimental as it induces significant non-uniformities of the device response with respect to the position of interaction. We have investigated these features by imaging the response of CVD diamond using a micrometer size focused X-ray beam. The comparison with the grain structure showed that it has a strong influence on the field distribution. We present here recent developments studied at CEA in Saclay for the optimisation of the material with respect to the specific requirements of several applications. They include radiation hard counters; X-ray intensity, shape and beam position monitors, solar blind photodetectors, and high dose rate gamma-meters. (orig.)

  6. Fabrication of Pt nanoparticles-decorated CVD diamond electrode for biosensor applications.

    Science.gov (United States)

    Song, Min-Jung; Kim, Jong-Hoon; Lee, Seung-Koo; Lim, Dae-Soon

    2011-01-01

    An electrochemical biosensor was developed using boron-doped diamond (BDD) as an electrode material. To enhance the electrical performance of the electrode, the BDD electrode was decorated with Pt-nanoparticles (Pt-NPs) by electrochemical deposition. Their morphology according to the applied potentials for the synthesis of Pt-NPs was characterized by SEM. To identify the performance of the electrode modified with Pt-NPs, glucose detection was used as a sample sensing process, and the results were compared with those of a gold electrode and a bare BDD electrode. The electrochemical characteristics of the modified electrode were examined by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The BDD electrode with the Pt-NPs showed higher sensitivity and a lower detection limit than the Au electrode and BDD electrode. The proposed biosensor based on the Pt-NPs decorated BDD electrode showed high sensitivity, a low detection limit, fast direct electron transfer and good stability. PMID:21985922

  7. Proceedings of the conference on electrochemistry of carbon allotropes: Graphite, fullerenes and diamond

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, K. [ed.] [Lawrence Berkeley National Lab., CA (United States); Scherson, D. [ed.] [Case Western Reserve Univ., Cleveland, OH (United States)

    1998-02-01

    This conference provided an opportunity for electrochemists, physicists, materials scientists and engineers to meet and exchange information on different carbon allotropes. The presentations and discussion among the participants provided a forum to develop recommendations on research and development which are relevant to the electrochemistry of carbon allotropes. The following topics which are relevant to the electrochemistry of carbon allotropes were addressed: Graphitized and disordered carbons, as Li-ion intercalation anodes for high-energy-density, high-power-density Li-based secondary batteries; Carbons as substrate materials for catalysis and electrocatalysis; Boron-doped diamond film electrodes; and Electrochemical characterization and electrosynthesis of fullerenes and fullerene-type materials. Abstracts of the presentations are presented.

  8. 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.

  9. Application of diamond based beam loss monitors

    International Nuclear Information System (INIS)

    The LHC has an operational stored energy of 130MJ per beam. Only a small percentage of beam losses in the LHC equipment can damage material or lead to magnet quenches. Therefore, it is important to monitor different types of beam losses, e.g. scattering on residual gas particles, UFOs, collisions and injection losses. A detailed understanding of beam loss mechanisms is necessary to reduce them and ensure save operation. Two different beam loss monitors are installed in the LHC tunnel: ionization chambers and diamond sensors. Ionization chambers trigger a beam dump if beam losses exceed a certain threshold. They have a time resolution of 40um (half LHC turn) which is not sufficient to resolve bunch-by-bunch beam losses. Diamond sensors have a nanosecond time resolution and can therefore detect bunch-by-bunch beam losses. This time resolution allows an analysis of various types of beam losses and an understanding of the mechanisms. For the first time beam loss intensities were measured bunch-by-bunch caused by different origins of losses. Beam loss measurements using diamond sensors will be presented. The results are compared to simulations and good qualitative agreement was found. The potential of diamond sensors for LHC and experiment applications are discussed.

  10. Application of diamond based beam loss monitors

    Energy Technology Data Exchange (ETDEWEB)

    Hempel, Maria [Brandenburgische Technische Univ. Cottbus (Germany); DESY, Zeuthen (Germany); CERN, Geneva (Switzerland); Baer, Tobias [CERN, Geneva (Switzerland); Hamburg Univ. (Germany); Castro Carballo, Elena Maria [DESY, Zeuthen (Germany); Lohmann, Wolfgang [Brandenburgische Technische Univ. Cottbus (Germany); DESY, Zeuthen (Germany); Schmidt, Ruediger [CERN, Geneva (Switzerland)

    2013-07-01

    The LHC has an operational stored energy of 130MJ per beam. Only a small percentage of beam losses in the LHC equipment can damage material or lead to magnet quenches. Therefore, it is important to monitor different types of beam losses, e.g. scattering on residual gas particles, UFOs, collisions and injection losses. A detailed understanding of beam loss mechanisms is necessary to reduce them and ensure save operation. Two different beam loss monitors are installed in the LHC tunnel: ionization chambers and diamond sensors. Ionization chambers trigger a beam dump if beam losses exceed a certain threshold. They have a time resolution of 40um (half LHC turn) which is not sufficient to resolve bunch-by-bunch beam losses. Diamond sensors have a nanosecond time resolution and can therefore detect bunch-by-bunch beam losses. This time resolution allows an analysis of various types of beam losses and an understanding of the mechanisms. For the first time beam loss intensities were measured bunch-by-bunch caused by different origins of losses. Beam loss measurements using diamond sensors will be presented. The results are compared to simulations and good qualitative agreement was found. The potential of diamond sensors for LHC and experiment applications are discussed.

  11. Quantum sensors based on single diamond defects

    International Nuclear Information System (INIS)

    NV centers in diamond are promising sensors able to detect electric and magnetic fields at nanoscale. Here we report on the detection of biomolecules using magnetic noise induced by their electron and nuclear spins. Presented results show first steps towards establishing novel sensing technology for visualizing single proteins and study of their dynamics. (author)

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

    International Nuclear Information System (INIS)

    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 (Deff) 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 (CuI+) migrated to the surface region when a continuous charge of electrons showered on the oxidized silicon wafer, which was also bombarded by primary O2+ ions. The CuI+ ions at the surface region diffused back to the bulk when the electron showering stopped. The D-SIMS recorded the real-time distribution of CuI+ 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 Deff values, and compared with other measurement techniques

  13. 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.

  14. 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.

  15. Boron-Doped Strontium-Stabilized Bismuth Cobalt Oxide Thermoelectric Nanocrystalline Ceramic Powders Synthesized via Electrospinning

    Science.gov (United States)

    Koçyiğit, Serhat; Aytimur, Arda; Çınar, Emre; Uslu, İbrahim; Akdemir, Ahmet

    2014-01-01

    Boron-doped strontium-stabilized bismuth cobalt oxide thermoelectric nanocrystalline ceramic powders were produced by using a polymeric precursor technique. The powders were characterized by using x-ray diffraction (XRD), scanning electron microscopy (SEM), and physical properties measurement system (PPMS) techniques. The XRD results showed that these patterns have a two-phase mixture. The phases are face-centered cubic (fcc) and body-centered cubic (bcc). Values of the crystallite size, dislocation density, and microstrain were calculated by using the Scherrer equation. The lattice parameters were calculated for fcc and bcc phases. The SEM results showed that needle-like grains are formed in boron-undoped composite materials, but the needle-like grains changed to the plate-like grains with the addition of boron. The distribution of the nanofiber diameters was calculated and the average diameter of the boron-doped sample is smaller than the boron-undoped one. PPMS values showed that the electrical resistivity values decreased, but the thermal conductivity values, the Seebeck coefficients, and figure of merit ( ZT) increased with increasing temperature for the two samples.

  16. 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)

  17. 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.

  18. 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.

  19. 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).

  20. 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.

  1. 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

  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. Diamond Nanowires: A Novel Platform for Electrochemistry and Matrix-Free Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Sabine Szunerits

    2015-05-01

    Full Text Available Over the last decades, carbon-based nanostructures have generated a huge interest from both fundamental and technological viewpoints owing to their physicochemical characteristics, markedly different from their corresponding bulk states. Among these nanostructured materials, carbon nanotubes (CNTs, and more recently graphene and its derivatives, hold a central position. The large amount of work devoted to these materials is driven not only by their unique mechanical and electrical properties, but also by the advances made in synthetic methods to produce these materials in large quantities with reasonably controllable morphologies. While much less studied than CNTs and graphene, diamond nanowires, the diamond analogue of CNTs, hold promise for several important applications. Diamond nanowires display several advantages such as chemical inertness, high mechanical strength, high thermal and electrical conductivity, together with proven biocompatibility and existence of various strategies to functionalize their surface. The unique physicochemical properties of diamond nanowires have generated wide interest for their use as fillers in nanocomposites, as light detectors and emitters, as substrates for nanoelectronic devices, as tips for scanning probe microscopy as well as for sensing applications. In the past few years, studies on boron-doped diamond nanowires (BDD NWs focused on increasing their electrochemical active surface area to achieve higher sensitivity and selectivity compared to planar diamond interfaces. The first part of the present review article will cover the promising applications of BDD NWS for label-free sensing. Then, the potential use of diamond nanowires as inorganic substrates for matrix-free laser desorption/ionization mass spectrometry, a powerful label-free approach for quantification and identification of small compounds, will be discussed.

  4. 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.

  5. 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

  6. A multiple quantum NMR (MQNMR) study of hydrogen microstructure in boron doped a-Si:H

    International Nuclear Information System (INIS)

    In this paper, an IR and multiple quantum NMR (MQNMR) study of hydrogen microstructure in three boron doped a-Si:H is discussed. The total Si-bonded H content of all films was 6.5 ± 1.0 at. % as determined by the 640 cm-1 IR wagging mode, but their boron content, which was determined by secondary ion mass spectrometry, ranged from 0.02 to 0.3 at %. The number of correlated hydrogen, as measured at a preparation time of 600 μs, was found to be more weakly dependent on the boron content than previously observed in phosphorous-doped glow-discharge films. Upon annealing at 220 degrees C the MQNMR spectrum show a moderate increase in the number of correlated hydrogen in all three samples

  7. Selective detector of cosmic particles based on diamond sensitive elements

    Science.gov (United States)

    Altukhov, A. A.; Zaharchenko, K. V.; Kolyubin, V. A.; Lvov, S. A.; Nedosekin, P. G.; Tyurin, E. M.; Ibragimov, R. F.; Kadilin, V. V.; Nikolaev, I. V.

    2016-02-01

    The article describes the device for selective registration of electrons, protons and heavy ions fluxes from the solar and galactic cosmic rays in the twelve energy ranges, built on a base of diamond detector. The use of the diamond detectors allowed for the creation a device for registration of cosmic particles fluxes at the external spacecraft surface with the resource not less than 20 years. Selective detector is aimed for continuous monitoring of radiation situation on board the spacecrafts, in order to predict the residual life of their work and prompt measures to actively protect the spacecraft when the flow of cosmic particles is sharply increased.

  8. 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.

  9. Batch fabrication of mesoporous boron-doped nickel oxide nanoflowers for electrochemical capacitors

    International Nuclear Information System (INIS)

    Highlights: • A new facile liquid-phase method has been employed for synthesis boron-doped NiO nanoflowers. • The specific surface area of NiO is as high as 200 m2 g−1. • NiO nanoflowers exhibit a high specific capacitance of ∼1309 F g−1 at a charge and discharge current density of 3 A g−1. • NiO nanoflowers have excellent cycling ability and even after 2500 cycles there is no significant reduction in specific capacitance. - Abstract: Boron-doped nickel oxide (B-NiO) nanoflowers are prepared by simple thermal decomposition of nickel hydroxide. B-NiO is porous sphere with a diameter of about 400 nm. B-NiO nanoflowers are composed of approximately 30 nm nanoplates and the thickness of the nanosheets is approximately 3 nm. The specific surface area of the material is as high as 200 m2 g−1 and the pore size distribution curves of B-NiO has three typical peaks in the range of mesoporous (5 nm, 13 nm and 18 nm). As an electrode for supercapacitors, the crystalline B-NiO nanoflowers have favorable characteristics, for instance, a specific capacitance of 1309 F g−1 at a current density of 3 A g−1 and no significant reduction in Coulombic efficiency after 2500 cycles at 37.5 A g−1. This remarkable electrochemical performance will make B-NiO nanoflowers a promising electrode material for high performance supercapacitors

  10. The growth environments of sloan diamonds: inferences based on their carbon isotope composition

    International Nuclear Information System (INIS)

    Carbon isotope compositions have been determined from the Sloan diatremes of the Colorado-Wyoming State Line kimberlite district (North America). The diamonds were previously broken for a study of their mineral inclusions. Based on mineral inclusion composition, the Sloan diamonds are divided into the broad peridotitic and eclogitic categories found for diamonds worldwide. Group I is comprised entirely of peridotitic diamonds whereas most of the diamonds in Group II and Group III are of eclogitic affinity. Differences in diamond morphology and mass are found between the three groups. Significant variation in δ13C was documented within single diamonds. Carbon isotope modelling of the Sloan diamond data suggests that the ranges in δ13C found for Group I and Group II diamonds at Sloan could have been produced from relatively homogeneous carbon reservoirs undergoing Rayleigh fractionation. The Group III diamonds were probably not produced from a single, isotopically homogeneous carbon reservoir. It is possible that the wide range of δ13C values for Group III diamonds was formed from an initially inhomogeneous (primordial or recycled) carbon source. Alternatively, the Group III diamonds may have crystallized from a less inhomogeneous, 13C-depleted fraction remaining after crystallization of Group I and Group II diamonds. The latter posibility suggests that the full range of δ13C values found for Sloan diamonds could have been produced in stages from an initially homogeneous carbon source. 2 figs., 3 refs

  11. Molecularly Imprinted Polypyrrole Based Impedimentric Sensor for Theophylline Determination

    International Nuclear Information System (INIS)

    Highlights: • Sensor based on polypyrrole imprinted by theophylline (MIP) deposited on oxygen terminated boron-doped nanocrystalline diamond was developed. • This structure was applied as impedimetric sensor sensitive for theophylline. • Optimal polymer formation conditions suitable for MIP formation were elaborated. • Some analytical parameters were determined and evaluated. - Abstract: In this study development of impedimetric sensor based on oxygen terminated boron-doped nanocrystalline diamond (B:NCD:O) modified with theophylline imprinted polypyrrole is described. Hydrogen peroxide induced chemical formation of polypyrrole molecularly imprinted by theophylline was applied for the modification of conducting silicon substrate covered by B:NCD:O film. Non-imprinted polypyrrole layer was formed on similar substrate in order to prove efficiency of imprinted polypyrrole. Electrochemical impedance spectroscopy was applied for the evaluation of analyte-induced changes in electrochemical capacitance/resistance. The impact of polymerization duration on the capacitance of impedimetric sensor was estimated. A different impedance behavior was observed at different ratio of polymerized monomer and template molecule in the polymerization media. The influence of ethanol as additive to polymerization media on registered changes in capacitance/resistance was evaluated. Degradation of sensor stored in buffer solution was evaluated

  12. 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

  13. 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.

  14. Sensitivity of diamond-capped impedance transducer to Troger's base derivatives

    Czech Academy of Sciences Publication Activity Database

    Stehlík, Štěpán; Ižák, Tibor; Kromka, Alexander; Dolenský, B.; Havlík, M.; Rezek, Bohuslav

    Hasselt : SBDD XVII, 2012. s. 110-110. [Hasselt Diamond Workshop 2012 - SBDD XVII. 14.03.2012 - 16.03. 2012, Hasselt] Institutional research plan: CEZ:AV0Z10100521 Keywords : Troger's base derivatives * nanocrystalline diamond * molecular receptors * sensors * diamond-capped impedance transducer Subject RIV: BM - Solid Matter Physics ; Magnetism

  15. 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

  16. 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.

  17. 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.

  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. 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

  20. 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

  1. Focus on diamond-based photonics and spintronics

    International Nuclear Information System (INIS)

    The ability to control the state of individual atoms is a new challenge for science and technology in the 21st century. Currently, experiments on individual quantum systems such as trapped ions, single molecules, quantum dots, superconducting qubits and photons are crucial for the rapidly growing field of quantum information processing and communication. In general, solid state systems are preferable for scaling and the choice of material plays a crucial role; for example, in classical electronic devices continual performance enhancement and miniaturization is strongly linked to the success of silicon-based technology. For quantum applications, diamond has the potential to become the material of choice, because its large bandgap enables the control of optically active impurities and higher operation temperature. This focus issue collates original research contributions from some of the leading groups in the field as a showcase for the very latest developments in diamond-based quantum technologies. (editorial)

  2. Focus on diamond-based photonics and spintronics

    Science.gov (United States)

    Jelezko, Fedor; Wrachtrup, Jörg

    2012-10-01

    The ability to control the state of individual atoms is a new challenge for science and technology in the 21st century. Currently, experiments on individual quantum systems such as trapped ions, single molecules, quantum dots, superconducting qubits and photons are crucial for the rapidly growing field of quantum information processing and communication. In general, solid state systems are preferable for scaling and the choice of material plays a crucial role; for example, in classical electronic devices continual performance enhancement and miniaturization is strongly linked to the success of silicon-based technology. For quantum applications, diamond has the potential to become the material of choice, because its large bandgap enables the control of optically active impurities and higher operation temperature. This focus issue collates original research contributions from some of the leading groups in the field as a showcase for the very latest developments in diamond-based quantum technologies.

  3. Cluster Development of Zhengzhou Urban Agriculture Based on Diamond Model

    OpenAIRE

    Wu, De-hui

    2012-01-01

    Based on basic theory of Diamond Model, this paper analyzes the competitive power of Zhengzhou urban agriculture from production factors, demand conditions, related and supporting industries, business strategies and structure, and horizontal competition. In line with these situations, it introduces that the cluster development is an effective approach to lifting competitive power of Zhengzhou urban agriculture. Finally, it presents following countermeasures and suggestions: optimize spatial d...

  4. First principles study of Fe in diamond: A diamond-based half metallic dilute magnetic semiconductor

    International Nuclear Information System (INIS)

    Half-metallic ferromagnetic ordering in semiconductors, essential in the emerging field of spintronics for injection and transport of highly spin polarised currents, has up to now been considered mainly in III–V and II–VI materials. However, low Curie temperatures have limited implementation in room temperature device applications. We report ab initio Density Functional Theory calculations on the properties of Fe in diamond, considering the effects of lattice site, charge state, and Fermi level position. We show that the lattice sites and induced magnetic moments of Fe in diamond depend strongly on the Fermi level position and type of diamond co-doping, with Fe being energetically most favorable at the substitutional site in p-type and intrinsic diamond, while it is most stable at a divacancy site in n-type diamond. Fe induces spin polarized bands in the band gap, with strong hybridization between Fe-3d and C-2s,2p bands. We further consider Fe-Fe spin interactions in diamond and show that substitutional Fe+1 in p-type diamond exhibits a half-metallic character, with a magnetic moment of 1.0 μB per Fe atom and a large ferromagnetic stabilization energy of 33 meV, an order of magnitude larger than in other semiconductors, with correspondingly high Curie temperatures. These results, combined with diamond's unique properties, demonstrate that Fe doped p-type diamond is likely to be a highly suitable candidate material for spintronics applications

  5. 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.

  6. Temperature dependence of the conductivity in large-grained boron-doped ZnO films

    Energy Technology Data Exchange (ETDEWEB)

    Myong, Seung Yeop; Steinhauser, Jerome; Schluechter, Romain; Fay, Sylvie; Vallat-Sauvain, Evelyne; Shah, Arvind; Ballif, Christophe [Institute of Microtechnology (IMT), University of Neuchatel, Rue A.-L. Breguet 2, CH-2000 Neuchatel (Switzerland); Ruefenacht, Alain [Institute of Physics, University of Neuchatel, CH-2000 Neuchatel (Switzerland)

    2007-09-06

    The temperature dependence of the conductivity is investigated as a function of boron doping in large-grained, degenerate polycrystalline ZnO films prepared by low-pressure chemical vapor deposition. Carrier transport in undoped and lightly doped films is mainly controlled by the grain boundary; field emission through grain boundaries limits the conductivity below 90 K, while thermally activated thermoionic-field emission leads to an increase in the conductivity with the temperature near room temperature. In contrast, carrier transport in highly doped films is mainly governed by intra-grain scattering, which does not depend on the temperature for degenerate electron gases, limits the mobility below 120 K, whereas a metallic behavior (decrease in conductivity with increasing temperature) is observed at room temperature, which is linked to the ionized impurity scattering. The transition between the ''semiconductor''-like and metallic-like behavior at room temperature takes place for a film with carrier concentration between 6 x 10{sup 19} and 9 x 10{sup 19} cm{sup -3}. (author)

  7. 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.

  8. Hydrogen passivation of interstitial iron in boron-doped multicrystalline silicon during annealing

    International Nuclear Information System (INIS)

    Effective hydrogenation of interstitial iron in boron-doped multicrystalline silicon wafers is reported. The multicrystalline silicon wafers were annealed with plasma-enhanced chemical vapour deposited silicon nitride films, at temperatures of 400 °C – 900 °C and for times from minutes to hours. At low temperatures where a combined effect of hydrogenation and precipitation of dissolved Fe is expected, results show that the hydrogenation process dominates the effect of precipitation. The concentrations of dissolved interstitial iron reduce by more than 90% after a 30-min anneal at temperatures between 600 and 900 °C. The most effective reduction occurs at 700 °C, where 99% of the initial dissolved iron is hydrogenated after 30 min. The results show that the observed reductions in interstitial Fe concentrations are not caused by the internal gettering of Fe at structural defects or by an enhanced diffusivity of Fe due to the presence of hydrogen. The hydrogenation process is conjectured to be the pairing of positively charged iron with negatively charged hydrogen, forming less recombination active Fe-H complexes in silicon

  9. 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.

  10. Structural modification of boron-doped ZnO layers caused by hydrogen outgassing

    Science.gov (United States)

    Lovics, R.; Csik, A.; 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 SiO2 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.

  11. Nanocrystalline diamond on Si solar cells for direct photoelectrochemical water splitting

    Czech Academy of Sciences Publication Activity Database

    Ashcheulov, Petr; Kusko, M.; Fendrych, František; Poruba, A.; Taylor, Andrew; Jäger, Aleš; Fekete, Ladislav; Kraus, I.; Kratochvílová, Irena

    2014-01-01

    Roč. 211, č. 10 (2014), s. 2347-2352. ISSN 1862-6300 R&D Projects: GA ČR GA13-31783S; GA MŠk(CZ) LM2011026 Grant ostatní: FP7-ITN MATCON(XE) 238201 Institutional support: RVO:68378271 Keywords : boron-doped diamond * solar cell * heterostructure * water splitting Subject RIV: CG - Electrochemistry Impact factor: 1.616, year: 2014

  12. Diamond-based heat spreaders for power electronic packaging applications

    Science.gov (United States)

    Guillemet, Thomas

    As any semiconductor-based devices, power electronic packages are driven by the constant increase of operating speed (higher frequency), integration level (higher power), and decrease in feature size (higher packing density). Although research and innovation efforts have kept these trends continuous for now more than fifty years, the electronic packaging technology is currently facing a challenge that must be addressed in order to move toward any further improvements in terms of performances or miniaturization: thermal management. Thermal issues in high-power packages strongly affect their reliability and lifetime and have now become one of the major limiting factors of power modules development. Thus, there is a strong need for materials that can sustain higher heat flux levels while safely integrating into the electronic package architecture. In such context, diamond is an attractive candidate because of its outstanding thermal conductivity, low thermal expansion, and high electrical resistivity. Its low heat capacity relative to metals such as aluminum or copper makes it however preferable for heat spreading applications (as a heat-spreader) rather than for dissipating the heat flux itself (as a heat sink). In this study, a dual diamond-based heat-spreading solution is proposed. Polycrystalline diamond films were grown through laser-assisted combustion synthesis on electronic substrates (in the U.S) while, in parallel, diamond-reinforced copper-matrix composite films were fabricated through tape casting and hot pressing (in France). These two types of diamond-based heat-spreading films were characterized and their microstructure and chemical composition were related to their thermal performances. Particular emphasize was put on the influence of interfaces on the thermal properties of the materials, either inside a single material (grain boundaries) or between dissimilar materials (film/substrate interface, matrix/reinforcement interface). Finally, the packaging

  13. QA programme based on clinical dosimeter with diamond detector

    International Nuclear Information System (INIS)

    The devices with ionizing chambers as the primary converters are traditionally used for dosimetry of the ionizing radiation in medicine and beam therapy. The application of the semiconductor detectors based on silicon is limited due to the high energy dependence of detection sensitivity, small radiation resource, dependence of the sensitivity on ambient temperature. Among the solid detectors, the diamond detectors are the most similar to the ionizing chambers as the carbon atomic number is close to the effective atomic number of air and biological tissue. The clinical dosimeter DKDa-01-'IPTP' based on the natural diamond detector was developed at the Institute in Physical and Technical Problems with the purpose of absolute and relative measurements in radiotherapy beams. The known properties of natural diamond detector provide high registration sensitivity, high radiation resistance and independence of the sensitivity on temperature, pressure. The small sensitive volume of the detector (1-6 mm3) allows measuring relative dose distributions with high spatial resolution. If calibrated in terms of absorbed dose to water in a Co-60 beam, the clinical dosimeter DKDa-01-'IPTP' provides determination of the absorbed dose to water of photon and electron beams in the radiotherapy dose rate and energy ranges without any additive corrections usually required during the ionizing chamber measurement. The relative error of these dose determinations is within ±2% that includes inherent features of the natural diamond detector (small energy dependence and dose rate dependence). The clinical dosimeter DKDa-01-'IPTP' was tested for the absolute measurements of proton radiation dose rate in the medical phasotron beam at the Joint Institute for Nuclear Research (JINR, Dubna). At the beginning, the dosimeter was calibrated in terms of absorbed dose to water against the secondary standard of gamma radiation absorbed dose to water (Co-60). The measurements were carried out at different

  14. Facile Synthesis of Boron-doped Graphene Nanosheets with Hierarchical Microstructure at Atmosphere Pressure for Metal-free Electrochemical Detection of Hydrogen Peroxide

    International Nuclear Information System (INIS)

    Graphical abstract: Display Omitted -- Highlights: • B-doped graphene nanosheets (BGNs) were used as a catalyst for sensing H2O2. • BGNs were synthesized by an atmospheric-pressure carbothermal reaction. • BGNs with hierarchical microstructure provide more electron transport pathways. • B atoms act as the active sites by transferring charges to neighboring C atoms. • Electrocatalytic ability of BGNs was characterized by a rotating disk electrode. -- Abstract: Hydrogen peroxide (H2O2) is an essential mediator for most of the oxidative biological reactions in enzyme-based biosensor systems, such as glucose oxidase, cholesterol oxidase, and alcohol oxidase. Synthesis of new catalysts to detect the concentration of H2O2 more precisely is indispensable for enzyme-based electrochemical biosensors. In this study, boron-doped graphene nanosheets (BGNs) with 2.2 atomic percentage (at%) boron doping level and a hierarchical microstructure were synthesized by an atmospheric-pressure carbothermal reaction as a noble-metal free catalyst for sensing H2O2. The isolated boron atoms on the BGNs surface act as the electrocatalytic sites by transferring charges to neighbor carbon atoms, and the hierarchical microstructure provides multidimensional electron transport pathways for charge transfer and therefore enhances the electrocatalytic ability. BGNs possess a higher reduction current in the cyclic voltammetry (CV) measurement than that of pristine graphene nanosheets (GNs) over the detection range of 0.0 to 10.0 mM at −0.4 V (vs. Ag/AgCl). The BGNs modified electrochemical sensor shows a linear range from 1.0 to 20.0 mM of H2O2 with a sensitivity of 266.7 ± 3.8 μA mM−1 cm−2 and limit of detection (LOD) of 3.8 μM at a signal-to-noise (S/N) ratio of 3. The beneficial hierarchical microstructure and the synergetic effects arising from doping boron in GNs accomplish the better performance of the BGNs modified electrochemical sensor

  15. 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.

  16. Cluster Development of Zhengzhou Urban Agriculture Based on Diamond Model

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Based on basic theory of Diamond Model,this paper analyzes the competitive power of Zhengzhou urban agriculture from production factors,demand conditions,related and supporting industries,business strategies and structure,and horizontal competition.In line with these situations,it introduces that the cluster development is an effective approach to lifting competitive power of Zhengzhou urban agriculture.Finally,it presents following countermeasures and suggestions:optimize spatial distribution for cluster development of urban agriculture;cultivate leading enterprises and optimize organizational form of urban agriculture;energetically develop low-carbon agriculture to create favorable ecological environment for cluster development of urban agriculture.

  17. 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...

  18. 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...

  19. 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. PMID:26544917

  20. Application of diamond based beam loss monitors at LHC

    International Nuclear Information System (INIS)

    collimators. Ionization chambers have a time resolution of 40 s that is a half LHC turn and in case of a large beam loss, they request a beam dump. Another type of beam loss monitors are diamond sensors because of a time resolution of about one nanosecond and high radiation hardness. One diamond detector system is located in the cleaning region of the LHC and is able to detect various types of beam losses. Another diamond detector system (BCM1F) is installed inside the CMS detector to protect the CMS from adverse beam conditions. BCM1F monitors also the luminosity during collisions and delivers important beam parameters. Additional condition monitors, based on the BCM1F system, are located next to CMS, near to LHCb and ALICE to measure large beam losses in the LHC ring. The process of a beam loss due to dust particles is explained, and additional simulations were done to understand these process in more detail. The result of the simulation are also given. Beam loss data recorded by the diamond sensors in the cleaning region and the BCM1F diamonds are presented.

  1. Application of diamond based beam loss monitors at LHC

    Energy Technology Data Exchange (ETDEWEB)

    Hempel, Maria

    2013-04-15

    the LHC, especially near each quadrupole and next to collimators. Ionization chambers have a time resolution of 40 s that is a half LHC turn and in case of a large beam loss, they request a beam dump. Another type of beam loss monitors are diamond sensors because of a time resolution of about one nanosecond and high radiation hardness. One diamond detector system is located in the cleaning region of the LHC and is able to detect various types of beam losses. Another diamond detector system (BCM1F) is installed inside the CMS detector to protect the CMS from adverse beam conditions. BCM1F monitors also the luminosity during collisions and delivers important beam parameters. Additional condition monitors, based on the BCM1F system, are located next to CMS, near to LHCb and ALICE to measure large beam losses in the LHC ring. The process of a beam loss due to dust particles is explained, and additional simulations were done to understand these process in more detail. The result of the simulation are also given. Beam loss data recorded by the diamond sensors in the cleaning region and the BCM1F diamonds are presented.

  2. 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).

  3. 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.

  4. PREFACE: Science's gem: diamond science 2009 Science's gem: diamond science 2009

    Science.gov (United States)

    Mainwood, Alison; Newton, Mark E.; Stoneham, Marshall

    2009-09-01

    devices, exploiting excellent quality boron doped p-type material, can be designed [3]. Electrical contacts can be tricky to fabricate, but progress is being made here [3, 27]. Diamond is perceived as unacceptably expensive, but for a high-quality device for an exceptional environment, this is not a problem. Carbon-based electronic materials are strikingly diverse. They include diamond, graphite, nanotubes and buckyball structures, amorphous carbons, and nanodiamond. Add hydrogen and one has a range of diamond-like carbons and the wealth of organics. Such carbon-based materials include small molecules and polymers: impressive insulators, semiconducting and conducting polymers, switchable forms, superconducting and magnetic forms, and some with the highest electrical conductivities of any material. Diamond-like carbons can have controllable mechanical properties from the viscoelastic to the highly rigid. Photochemistry brings opportunities for novel processing methods. Even water-based processing may sometimes be possible (alas, not for diamond), and additional tools like self-organisation of organic molecules on surfaces have been demonstrated. The best carbons have impressive, sometimes supreme, performances, including the mobility and optical properties of diamond, spin-conserving transport in carbon nanotubes, and electron emission. For almost all measures of performance, there is some carbon-based material that performs better than silicon. Might hybrid carbon-based materials be more successful even than silicon [28]? Should we think less about 'diamond' and more about the integration of diamond as one component of carbon electronics? Device fabrication needs lithography optics and resists, and processing at the anticipated smaller scales may well exploit new electronic excitation methods. Alternative dielectrics and interconnect materials introduce new compatibility issues, and there are further varied constraints from displays, spintronic components, electron

  5. Heat treatment induced structural modification of boron-doped ZnO layers

    International Nuclear Information System (INIS)

    Complete text of publication follows. In the case of solar cells, to optimize the properties of photovoltaic (PV) modules one of the important issues is the diffusion of sodium from the glass substrate into the layered structure. There are many discussions about the role of the Na during preparation of PV modules: i) selenisation of Mo interlayer between the ZnO and active layers to obtain a lower series electrical resistance without changing the transmittance of the ZnO layer; ii) the diffusion of Na from glass substrate to a-Si:H/c- Si or Cu(In,Ga)Se2 (CIGS) layer. In certain cases the ZnO layers must be annealed in air or in hydrogen atmosphere to improve electrical conductivity. At the same time, the annealing temperature induces diffusion of Na. Thus, detailed investigation of appropriate layered materials is required. Present work was initiated in the framework of developing the solar cell technology. The goal was to investigate suitable substrates appropriate for desirable Na diffusion. Borondoped ZnO layers were prepared by Low Pressure Chemical Vapour Deposition (LPCVD) method on three different types of substrate: soda-lime windows glass (s1) and Schott AF-45 alkali-free thin glass (s2) were selected for our experiments. Polished Si substrate (s3) was used as a reference sample. After sample preparation procedure, the samples were annealed in air at 300 deg C. As it can seen in Fig.1, significant structural changes occurred at the surface of boron-doped ZnO layers in the form of bubble formation. We experienced that Na diffusion directly connected with hydrogen precipitation. Formation of bubbles observed was most probably due to enhanced hydrogen accumulation from the ZnO:B structure or decomposition of physisorbed precursor. After the annealing, the bubbles on the sample surface were blown up and cracked, i.e. were destroyed on polished Si and Soda-lime glass substrates. However, the samples prepared on AF 45 Schott alkali-free thin glass substrate had

  6. Could one make a diamond-based quantum computer?

    International Nuclear Information System (INIS)

    We assess routes to a diamond-based quantum computer, where we specifically look towards scalable devices, with at least 10 linked quantum gates. Such a computer should satisfy the deVincenzo rules and might be used at convenient temperatures. The specific examples that we examine are based on the optical control of electron spins. For some such devices, nuclear spins give additional advantages. Since there have already been demonstrations of basic initialization and readout, our emphasis is on routes to two-qubit quantum gate operations and the linking of perhaps 10-20 such gates. We analyse the dopant properties necessary, especially centres containing N and P, and give results using simple scoping calculations for the key interactions determining gate performance. Our conclusions are cautiously optimistic: it may be possible to develop a useful quantum information processor that works above cryogenic temperatures.

  7. Enhanced Growth and Osteogenic Differentiation of Human Osteoblast-Like Cells on Boron-Doped Nanocrystalline Diamond Thin Films

    Czech Academy of Sciences Publication Activity Database

    Grausová, Ľubica; Kromka, Alexander; Burdíková, Zuzana; Eckhardt, Adam; Rezek, Bohuslav; Vacík, Jiří; Haenen, K.; Lisá, Věra; Bačáková, Lucie

    2011-01-01

    Roč. 6, č. 6 (2011), e20943. E-ISSN 1932-6203 R&D Projects: GA AV ČR(CZ) KAN400480701; GA AV ČR(CZ) IAAX00100902; GA ČR(CZ) GAP108/11/0794 Grant ostatní: GA AV ČR(CZ) KAN400100701 Institutional research plan: CEZ:AV0Z50110509; CEZ:AV0Z10480505; CEZ:AV0Z10100521 Keywords : osteoblast-like cells * boron * NCD films Subject RIV: EI - Biotechnology ; Bionics Impact factor: 4.092, year: 2011

  8. 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...

  9. Micro-strip sensors based on CVD Diamond

    CERN Document Server

    Adam, W; Bergonzo, P; Bertuccio, G; Bogani, F; Borchi, E; Brambilla, A; Bruzzi, Mara; Colledani, C; Conway, J; D'Angelo, P; Dabrowski, W; Delpierre, P A; Deneuville, A; Dulinski, W; van Eijk, B; Fallou, A; Fizzotti, F; Foulon, F; Friedl, M; Gan, K K; Gheeraert, E; Hallewell, G D; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Kagan, H; Kania, D R; Kaplon, J; Kass, R; Koeth, T W; Krammer, Manfred; Lo Giudice, A; Lü, R; MacLynne, L; Manfredotti, C; Meier, D; Mishina, M; Moroni, L; Oh, A; Pan, L S; Pernicka, Manfred; Peitz, A; Perera, L P; Pirollo, S; Procario, M; Riester, J L; Roe, S; Rousseau, L; Rudge, A; Russ, J; Sala, S; Sampietro, M; Schnetzer, S R; Sciortino, S; Stelzer, H; Stone, R; Suter, B; Tapper, R J; Tesarek, R J; Trischuk, W; Tromson, D; Vittone, E; Walsh, A M; Wedenig, R; Weilhammer, Peter; Wetstein, M; White, C; Zeuner, W; Zoeller, M M

    2000-01-01

    In this article we present the performance of recent chemical vapour deposition (CVD) diamond micro-strip sensors in beam tests. In addition we present the first comparison of a CVD diamond micro-strip sensor before and after proton irradiation.

  10. Micro-strip sensors based on CVD diamond

    Energy Technology Data Exchange (ETDEWEB)

    Adam, W.; Berdermann, E.; Bergonzo, P.; Bertuccio, G.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; D' Angelo, P.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foulon, F.; Friedl, M.; Gan, K.K.; Gheeraert, E.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Koeth, T.; Krammer, M.; Logiudice, A.; Lu, R.; Mac Lynne, L.; Manfredotti, C.; Meier, D. E-mail: dirk.meier@cern.ch; Mishina, M.; Moroni, L.; Oh, A.; Pan, L.S.; Pernicka, M.; Peitz, A.; Perera, L.; Pirollo, S.; Procario, M.; Riester, J.L.; Roe, S.; Rousseau, L.; Rudge, A.; Russ, J.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Suter, B.; Tapper, R.J.; Tesarek, R.; Trischuk, W.; Tromson, D.; Vittone, E.; Walsh, A.M.; Wedenig, R.; Weilhammer, P.; Wetstein, M.; White, C.; Zeuner, W.; Zoeller, M

    2000-10-11

    In this article we present the performance of recent chemical vapour deposition (CVD) diamond micro-strip sensors in beam tests. In addition, we present the first comparison of a CVD diamond micro-strip sensor before and after proton irradiation.

  11. Micro-strip sensors based on CVD diamond

    International Nuclear Information System (INIS)

    In this article we present the performance of recent chemical vapour deposition (CVD) diamond micro-strip sensors in beam tests. In addition, we present the first comparison of a CVD diamond micro-strip sensor before and after proton irradiation

  12. Effects of copper-based alloy on the synthesis of single-crystal diamond

    CERN Document Server

    Chen Li Xue; Ma Hong An; Jia Xiao Peng; Wakatsuki, M; Zou Guang Tian

    2002-01-01

    The catalytic effects of copper-based alloys in diamond growth have been investigated. A single crystal of diamond has been obtained by the temperature gradient method (TGM), using Cu-Mn-Co and Cu-Co alloys as catalysts. It was found that the melted Cu-Mn-Co and Cu-Co alloys show low viscosity. The eutectic temperatures of these two alloys with graphite were between 1130 and 1150 deg. C, and the temperature of the transition to diamond was over 1300 deg. C at 5.5 GPa. High-quality diamond could not be obtained in Cu-Co alloy by the TGM. Our results suggest that adding Cu to a catalyst cannot decrease the reaction temperature for diamond growth.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. Diffusion-driven precipitate growth and ripening of oxygen precipitates in boron doped silicon by dynamical x-ray diffraction

    International Nuclear Information System (INIS)

    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/cm2) 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

  18. 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

  19. 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.

  20. Electrochemically assisted deposition of hydroxyapatite on Ti6Al4V substrates covered by CVD diamond films - Coating characterization and first cell biological results.

    Science.gov (United States)

    Strąkowska, Paulina; Beutner, René; Gnyba, Marcin; Zielinski, Andrzej; Scharnweber, Dieter

    2016-02-01

    Although titanium and its alloys are widely used as implant material for orthopedic and dental applications they show only limited corrosion stability and osseointegration in different cases. The aim of the presented research was to develop and characterize a novel surface modification system from a thin diamond base layer and a hydroxyapatite (HAp) top coating deposited on the alloy Ti6Al4V widely used for implants in contact with bone. This coating system is expected to improve both the long-term corrosion behavior and the biocompatibility and bioactivity of respective surfaces. The diamond base films were obtained by Microwave Plasma Assisted Chemical Vapor Deposition (MW-PACVD); the HAp coatings were formed in aqueous solutions by electrochemically assisted deposition (ECAD) at varying polarization parameters. Scanning electron microscopy (SEM), Raman microscopy, and electrical conductivity measurements were applied to characterize the generated surface states; the calcium phosphate coatings were additionally chemically analyzed for their composition. The biological properties of the coating system were assessed using hMSC cells analyzing for cell adhesion, proliferation, and osteogenic differentiation. Varying MW-PACVD process conditions resulted in composite coatings containing microcrystalline diamond (MCD/Ti-C), nanocrystalline diamond (NCD), and boron-doped nanocrystalline diamond (B-NCD) with the NCD coatings being dense and homogeneous and the B-NCD coatings showing increased electrical conductivity. The ECAD process resulted in calcium phosphate coatings from stoichiometric and non-stoichiometric HAp. The deposition of HAp on the B-NCD films run at lower cathodic potentials and resulted both in the highest coating mass and the most homogenous appearance. Initial cell biological investigations showed an improved cell adhesion in the order B-NCD>HAp/B-NCD>uncoated substrate. Cell proliferation was improved for both investigated coatings whereas ALP

  1. Materials science and fabrication processes for a new MEMS technology based on ultrananocrystalline diamond thin films

    International Nuclear Information System (INIS)

    Most MEMS devices are currently based on silicon because of the available surface machining technology. However, Si has poor mechanical and tribological properties which makes it difficult to produce high performance Si based MEMS devices that could work reliably, particularly in harsh environments; diamond, as a superhard material with high mechanical strength, exceptional chemical inertness, outstanding thermal stability and superior tribological performance, could be an ideal material for MEMS. A key challenge for diamond MEMS is the integration of diamond films with other materials. Conventional CVD thin film deposition methods produce diamond films with large grains, high internal stress, poor intergranular adhesion and very rough surfaces, and are consequently ill-suited for MEMS applications. Diamond-like films offer an alternative, but are deposited using physical vapour deposition methods unsuitable for conformal deposition on high aspect ratio features, and generally they do not exhibit the outstanding mechanical properties of diamond. We describe a new ultrananocrystalline diamond (UNCD) film technology based on a microwave plasma technique using argon plasma chemistries that produce UNCD films with morphological and mechanical properties that are ideally suited for producing reliable MEMS devices. We have developed lithographic techniques for the fabrication of UNCD MEMS components, including cantilevers and multilevel devices, acting as precursors to micro-bearings and gears, making UNCD a promising material for the development of high performance MEMS devices. We also review the mechanical, tribological, electronic transport, chemical and biocompatibility properties of UNCD, which make this an ideal material for reliable, long endurance MEMS device use. (topical review)

  2. Single Crystalline CVD Diamond Based Devices for Power Electronics Applications

    OpenAIRE

    Adrian, Ehrnebo

    2014-01-01

    Chemical vapor deposited single-crystalline diamond has rare material properties such as thermal conductivity five times as high as copper, a wide band gap, a high breakdown field and high carrier mobilities. This makes it a very interesting material for high power, high frequency and high temperature applications. In this thesis work, metal oxide semiconductor (MOS) capacitors of diamond substrate were fabricated and analyzed. The MOS capacitor is a building block of the metal oxide semicond...

  3. Evaluation of the insertion efficiencies of tapered silicon nanoneedles and invasiveness of diamond nanoneedles in manipulations of living single cells.

    Science.gov (United States)

    Han, Sung-Woong; Ryu, Seunghwan; Kitagawa, Taro; Uetsuka, Hiroshi; Fujimori, Naoji; Aoki, Yukihiro; Ota, Ryo; Amemiya, Yosuke; Shimamoto, Nobuo; Nakamura, Chikashi; Miyake, Jun

    2009-01-01

    We have been developing a low invasive cell manipulation technology based on inserting an ultra-thin needle--"nanoneedle"--into a living cell by using an atomic force microscope (AFM). The nanoneedle, made from a silicon AFM tip by focused-ion-beam etching, has a diameter of several hundred nanometers and a length of about 10 microns. Successful insertion of the nanoneedle into the cell can be confirmed by the appearance of a steep relaxation of repulsive force in the force-distance curve as monitored by the AFM system. This technology, termed "cell surgery", can be applied for the detection of intracellular proteins in a living cell or for highly efficient gene transfer. The present study shows that the durability of a tapered nanoneedle is superior to that of a cylindrical nanoneedle, and that a proper aspect ratio for the tapered nanoneedle must be chosen to maintain sufficient insertion efficiency for a particular target cell: tapered nanoneedles of an aspect ratio over 20 showed high insertion efficiency for various kinds of mammalian cells. We then used diamond for the material of the nanoneedle because its specific properties, such as high stiffness, heat conductivity, and electrical conductivity capacitated by boron doping, were deemed useful for the analysis and manipulation of intracellular phenomena. We compared the capability of the diamond nanoneedle in cell manipulation with that of the silicon nanoneedle. Evaluation of the effect of the former on transcription efficiency and localization analysis of p53 expression revealed the low invasiveness for cell manipulation as was also the case for the silicon nanoneedle. We also succeeded in achieving highly efficient plasmid DNA delivery into a mouse fibroblast C3H10T1/2 using the diamond nanoneedle. The diamond nanoneedle is expected to contribute to the versatility of "cell surgery" technology. PMID:21471661

  4. Injection quality measurements with diamond based particle detectors

    CERN Document Server

    Stein, Oliver; CERN. Geneva. ATS Department

    2016-01-01

    During the re-commissioning phase of the LHC after the long shutdown 1 very high beam losses were observed at the TDI during beam injection. The losses reached up to 90% of the dump threshold. To decrease the through beam losses induced stress on the accelerator components these loss levels need to be reduced. Measurements with diamond based particle detectors (dBLMs), which have nano-second time resolution, revealed that the majority of these losses come from recaptured SPS beam surrounding the nominal bunch train. In this MD the injection loss patterns and loss intensities were investigated in greater detail. Performed calibration shots on the TDI (internal beam absorber for injection) gave a conversion factor from impacting particles intensities to signal in the dBLMs (0.1Vs/109 protons). Using the SPS tune kicker for cleaning the recaptured beam in the SPS and changing the LHC injection kicker settings resulted in a reduction of the injection losses. For 144 bunch injections the loss levels were decreased...

  5. Silica based polishing of {100} and {111} single crystal diamond

    International Nuclear Information System (INIS)

    Diamond is one of the hardest and most difficult to polish materials. In this paper, the polishing of {111} and {100} single crystal diamond surfaces by standard chemical mechanical polishing, as used in the silicon industry, is demonstrated. A Logitech Tribo Chemical Mechanical Polishing system with Logitech SF1 Syton and a polyurethane/polyester polishing pad was used. A reduction in roughness from 0.92 to 0.23 nm root mean square and 0.31 to 0.09 nm rms for {100} and {111} samples respectively was observed. (paper)

  6. Stratigraphy of a diamond epitaxial three-dimensional overgrowth using doping superlattices

    Science.gov (United States)

    Lloret, F.; Fiori, A.; Araujo, D.; Eon, D.; Villar, M. P.; Bustarret, E.

    2016-05-01

    The selective doped overgrowth of 3D mesa patterns and trenches has become an essential fabrication step of advanced monolithic diamond-based power devices. The methodology here proposed combines the overgrowth of plasma-etched cylindrical mesa structures with the sequential growth of doping superlattices. The latter involve thin heavily boron doped epilayers separating thicker undoped epilayers in a periodic fashion. Besides the classical shape analysis under the scanning electron microscope relying on the appearance of facets corresponding to the main crystallographic directions and their evolution toward slow growing facets, the doping superlattices were used as markers in oriented cross-sectional lamellas prepared by focused ion beam and observed by transmission electron microscopy. This stratigraphic approach is shown here to be applicable to overgrown structures where faceting was not detectable. Intermediate growth directions were detected at different times of the growth process and the periodicity of the superlattice allowed to calculate the growth rates and parameters, providing an original insight into the planarization mechanism. Different configurations of the growth front were obtained for different sample orientations, illustrating the anisotropy of the 3D growth. Dislocations were also observed along the lateral growth fronts with two types of Burger vector: b 01 1 ¯ = /1 2 [ 01 1 ¯ ] and b 112 = /1 6 [ 112 ] . Moreover, the clustering of these extended defects in specific regions of the overgrowth prompted a proposal of two different dislocation generation mechanisms.

  7. Ammonium hydroxide (NH{sub 4}OH) as etch-stop chemical for highly boron-doped silicon {delta}-layers

    Energy Technology Data Exchange (ETDEWEB)

    Hammer, Oliver; Palitschka, Florian; Lochner, Helmut; Kubot, Tina; Kulaga-Egger, Dorota; Beckmeier, Daniel; Axt, Carolin; Biba, Josef; Schindler, Ronny; Dressler, Marc; Sulima, Torsten; Hansch, Walter [Universitaet der Bundeswehr Muenchen, Institut fuer Physik, Neubiberg (Germany)

    2010-07-01

    The downscaling process in current microelectronics results in smaller devices and thinner layers. A proper etch-stop for such thin layers, e.g. boron-doped {delta}-layer (<10nm) in a vertical device, becomes more and more challenging. Therefore an etchant with an exceedingly high selectivity to boron-doped silicon is needed. Only two wet-chemical silicon etchants, TMAH and the not common NH{sub 4}OH, are capable for CMOS technology and are not too highly toxic. The major advantage of NH{sub 4}OH in comparison to TMAH is its high selectivity of 1:8000 for intrinsic silicon with respect to boron-doped silicon. The disadvantages are formation of hillocks and more pronounced surface roughness compared to TMAH. We optimize etching parameters by variation of the etch temperature, the concentration of NH{sub 4}OH in water and the ratio of 2-propanol in the solution to achieve an etch-stop at a {delta}-layer without breaking it. Recent experiments show that a solution of TMAH and 2-propanol decreases the surface roughness and the formation of hillocks. Due to this we also perform tests with 2-propanol in a NH{sub 4}OH solution. Finally we etch a bulk unipolar device (BUD) to determine the electrical characteristics of the exposed {delta}-layer.

  8. Diamond cutters' grinders

    Science.gov (United States)

    Romanov, B. F.

    1985-03-01

    The development of diamond tool designs is determined by the development of the technology for the synthesis of artificial diamonds. The technology of syntehsizing artificial diamonds involves the production of mono and polycrystalline diamonds and composition diamond-containing materials. High strength and thermally stable monocrystalline diamonds brands AS30 to AS80 in a size of up to 800 micrometers, and polycrystalline diamonds: black diamonds, ballas (Synthetic Fiber) in a size up to 10mm, are manufactured. Production of single-layer and double-layer diamond plates used in cutting tools is organized. The raw materials base with the constant decrease in the use of natural diamonds is the basis for the development of the manufacture of a wide array of diamond tools. New areas of applications for tools using natural diamonds, such as diamond cutters for turning high-precision parts, straightening tools, hardness gages are outlined. Diamond cutters with natural diamonds are used to grind surfaces which have exceptionally high requirements with respect to the reflecting capacity and roughness.

  9. 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.

  10. Fabrication of diamond based quartz crystal microbalance gas sensor

    Czech Academy of Sciences Publication Activity Database

    Varga, Marián; Laposa, A.; Kulha, P.; Davydova, Marina; Kroutil, J.; Husák, M.; Kromka, Alexander

    Vol. 605. Zurich : Trans Tech Publications, 2014 - (Hristoforou, E.; Vlachos, D.), s. 589-592 ISBN 9783038350514. ISSN 1013-9826. [International Conference on Materials and Applications for Sensors and Transducers /3./ (IC-MAST 2013). Praha (CZ), 13.09.2013-17.09.2013] R&D Projects: GA ČR(CZ) GAP108/11/0794 Institutional support: RVO:68378271 Keywords : diamond thin film * low temperature deposition * quartz crystal microbalance * gas sensor Subject RIV: JB - Sensors, Measurment, Regulation

  11. Diamond Based Electronics and Valleytronics : An experimental study

    OpenAIRE

    Kovi, Kiran Kumar

    2014-01-01

    Diamond is a promising semiconductor material for high power, high voltage, high temperature and high frequency applications due to its remarkable material properties: it has the highest thermal conductivity, it is the hardest material, chemically inert, radiation hard and has the widest transparency in the electromagnetic spectrum. It also exhibits excellent electrical properties like high breakdown field, high mobilities and a wide bandgap.  Hence, it may find applications in extreme condit...

  12. 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.

  13. 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.

  14. Excimer Laser Beam Analyzer Based on CVD Diamond

    Science.gov (United States)

    Girolami, Marco; Salvatori, Stefano; Conte, Gennaro

    2010-11-01

    1-D and 2-D detector arrays have been realized on CVD-diamond. The relatively high resistivity of diamond in the dark allowed the fabrication of photoconductive "sandwich" strip (1D) or pixel (2D) detectors: a semitransparent light-receiving back-side contact was used for detector biasing. Cross-talk between pixels was limited by using intermediate guard contacts connected at the same ground potential of the pixels. Each pixel photocurrent was conditioned by a read-out electronics composed by a high sensitive integrator and a Σ-Δ ADC converter. The overall 500 μs conversion time allowed a data acquisition rate up to 2 kSPS. The measured fast photoresponse of the samples in the ns time regime suggests to use the proposed devices for fine tuning feedback of high-power pulsed-laser cavities, whereas solar-blindness guarantees high performance in UV beam diagnostics also under high intensity background illumination. Offering unique properties in terms of thermal conductivity and visible-light transparency, diamond represents one of the most suitable candidate for the detection of high-power UV laser emission. The technology of laser beam profiling is evolving with the increase of excimer lasers applications that span from laser-cutting to VLSI and MEMS technologies. Indeed, to improve emission performances, fine tuning of the laser cavity is required. In such a view, the development of a beam-profiler, able to work in real-time between each laser pulse, is mandatory.

  15. Proton recoil telescope based on diamond detectors for measurement of fusion neutrons

    CERN Document Server

    Caiffi, B; Ripani, M; Pillon, M; Taiuti, M

    2015-01-01

    Diamonds are very promising candidates for the neutron diagnostics in harsh environments such as fusion reactor. In the first place this is because of their radiation hardness, exceeding that of Silicon by an order of magnitude. Also, in comparison to the standard on-line neutron diagnostics (fission chambers, silicon based detectors, scintillators), diamonds are less sensitive to $\\gamma$ rays, which represent a huge background in fusion devices. Finally, their low leakage current at high temperature suppresses the detector intrinsic noise. In this talk a CVD diamond based detector has been proposed for the measurement of the 14 MeV neutrons from D-T fusion reaction. The detector was arranged in a proton recoil telescope configuration, featuring a plastic converter in front of the sensitive volume in order to induce the (n,p) reaction. The segmentation of the sensitive volume, achieved by using two crystals, allowed to perform measurements in coincidence, which suppressed the neutron elastic scattering backg...

  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. Nanocrystalline diamond microelectrode arrays fabricated on sapphire technology for high-time resolution of quantal catecholamine secretion from chromaffin cells.

    Science.gov (United States)

    Carabelli, V; Gosso, S; Marcantoni, A; Xu, Y; Colombo, E; Gao, Z; Vittone, E; Kohn, E; Pasquarelli, A; Carbone, E

    2010-09-15

    The quantal release of oxidizable molecules can be successfully monitored by means of polarized carbon fiber microelectrodes (CFEs) positioned in close proximity to the cell membrane. To partially overcome certain CFE limitations, mainly related to their low spatial resolution and lack of optical transparency, we developed a planar boron-doped nanocrystalline diamond (NCD) prototype, grown on a transparent sapphire wafer. Responsiveness to applied catecholamines as well as the electrochemical and optical properties of the NCD-based device were first characterized by cyclic voltammetry and optical transmittance measurements. By stimulating chromaffin cells positioned on the device with external KCl, well-resolved quantal exocytotic events could be detected either from one NCD microelectrode, or simultaneously from an array of four microelectrodes, indicating that the chip is able to monitor secretory events (amperometric spikes) from a number of isolated chromaffin cells. Spikes detected by the planar NCD device had comparable amplitudes, kinetics and vesicle diameter distributions as those measured by conventional CFEs from the same chromaffin cell. PMID:20570501

  18. Development of wide-ranged diamond-based detector unit for gamma radiation measurement

    Science.gov (United States)

    Baranova, M. A.; Boyko, A. V.; Chebyshev, S. B.; Cherkashin, I. I.; Kireev, V. P.; Petrov, V. I.

    2016-02-01

    In the article the description of wide-ranged diamond-based detector unit is given. Characteristics of the diamond detector were studied in current and in impulse mode. As well it was studied how detector's sensitivity depends on power doze within the limits from 10-3 to 0,4Gy/h (impulse mode) and from 10-1to 2 104Gy/h (current mode). On the basis of the obtained data it is possible to estimate about the possibility of using the detector to prevent emergency accident on a nuclear power plant and for everyday control at a nuclear power plant.

  19. Towards UV imaging sensors based on single-crystal diamond chips for spectroscopic applications

    International Nuclear Information System (INIS)

    The recent improvements achieved in the Homoepitaxial Chemical Vapour Deposition technique have led to the production of high-quality detector-grade single-crystal diamonds. Diamond-based detectors have shown excellent performances in UV and X-ray detection, paving the way for applications of diamond technology to the fields of space astronomy and high-energy photon detection in harsh environments or against strong visible light emission. These applications are possible due to diamond's unique properties such as its chemical inertness and visible blindness, respectively. Actually, the development of linear array detectors represents the main issue for a full exploitation of diamond detectors. Linear arrays are a first step to study bi-dimensional sensors. Such devices allow one to face the problems related to pixel miniaturisation and of signal read-out from many channels. Immediate applications would be in spectroscopy, where such arrays are preferred. This paper reports on the development of imaging detectors made by our groups, starting from the material growth and characterisation, through the design, fabrication and packaging of 2xn pixel arrays, to their electro-optical characterisation in terms of UV sensitivity, uniformity of the response and to the development of an electronic circuit suitable to read-out very low photocurrent signals. The detector and its electronic read-out were then tested using a 2x5 pixel array based on a single-crystal diamond. The results will be discussed in the framework of the development of an imager device for X-UV astronomy applications in space missions

  20. 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

  1. 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).

  2. Ultra-thin nanocrystalline diamond membranes as pressure sensors for harsh environments

    International Nuclear Information System (INIS)

    Glass and diamond are suitable materials for harsh environments. Here, a procedure for fabricating ultra-thin nanocrystalline diamond membranes on glass, acting as an electrically insulating substrate, is presented. In order to investigate the pressure sensing properties of such membranes, a circular, highly conductive boron-doped nanocrystalline diamond membrane with a resistivity of 38 mΩ cm, a thickness of 150 nm, and a diameter of 555 μm is fabricated in the middle of a Hall bar structure. During the application of a positive differential pressure under the membrane (0–0.7 bar), four point piezoresistive effect measurements are performed. From these measurements, it can be concluded that the resistance response of the membrane, as a function of differential pressure, is highly linear and sensitive

  3. Competitiveness Analysis of Processing Industry Cluster of Livestock Products in Inner Mongolia Based on "Diamond Model"

    OpenAIRE

    Yang, Xing-long; Ren, Ya-tong

    2012-01-01

    Using Michael Porter's "diamond model", based on regional development characteristics, we conduct analysis of the competitiveness of processing industry cluster of livestock products in Inner Mongolia from six aspects (the factor conditions, demand conditions, corporate strategy, structure and competition, related and supporting industries, government and opportunities). And we put forward the following rational recommendations for improving the competitiveness of processing industry cluster ...

  4. Polycrystalline diamond based detector for Z-pinch diagnosis

    International Nuclear Information System (INIS)

    Full text of publication follows: Z-pinch is a self-constricted plasma configuration, as well as a high efficient X-ray simulator with energy transfer coefficient in the range of 0.8% - 23% [1-4]. Characteristics of the X-ray from Z-pinch are very important for researches focusing on the physical processes of plasma [5-6]. A chemical vapour deposition (CVD) derived polycrystalline diamond film detector has been developed as the X-ray detector on Z-pinch at a high powerful pulsed electron beam accelerator named Qiangguang-I (current 1.4-2.1 MA, rising time 80-100 ns) in Northwest Institute of Nuclear Technology in P. R. China. This detector is 16 mm in diameter and 300 μm in thickness with gold electrodes on both sides. The dark current of the detector is lower than 60 pA with the electric field intensity of 3 V/μm. The charge collection efficiency is 60.8% with the electric field intensity of 1.67 V/μm. The energy response and the time response have been studied by both experiments and theoretical calculation. The spectral response to X-ray is flat over the range of 3-5 keV. The rising time of response pulse is 2-3 ns. This diamond detector acquires good experimental data which are in good agreement with the results got from the X-ray Diodes (XRDs) [7] on Z-pinch diagnosis at Qiangguang-I facility. These results show that the device we developed offers a good choice for Z-pinch diagnosis at high power electron beam accelerator. References: [1] R. B. Spielman, C. Deeney and G. A. Chandler, Phys of Plasmas 5, 5 (1998); [2] Proceedings of 10. IEEE International Pulsed Power Conference 1995, 1-2; [3] Proceedings of 11. IEEE International Pulsed Power Conference 1997, 23-36; [4] A. Qiu, Engineering Science 2, 9(2000); [5] A. Qiu, B. Kuai and Z. Zeng, Acta Physica Sinica 55, 11 (2006); [6] W. Wang, D. He and A. Qiu, High Power Laser and Particle Beams 15, 184(2003); [7] G. A. Chandler, C. Deeney and M. Cuneo, Review of Scientific Instruments 70, 1(1999). (authors)

  5. Hydrogen passivation effects on carbon dangling bond defects accompanying a nearby hydrogen atom in p-type Cd diamond

    Energy Technology Data Exchange (ETDEWEB)

    Mizuochi, N. [Graduate School of Library, Information and Media Studies, University of Tsukuba, 1-2 Kasuga, Tsukuba-City, Ibaraki 305-8550 (Japan) and Diamond Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan) and CREST JST - Japan Science and Technology (Japan)]. E-mail: mizuochi@slis.tsukuba.ac.jp; Ogura, M. [Diamond Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); CREST JST (Japan Science and Technology) (Japan); Isoya, J. [Graduate School of Library, Information and Media Studies, University of Tsukuba, 1-2 Kasuga, Tsukuba-City, Ibaraki 305-8550 (Japan); Diamond Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Okushi, H. [Diamond Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); CREST JST (Japan Science and Technology) (Japan); Yamasaki, S. [Diamond Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); CREST JST (Japan Science and Technology) (Japan); Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8577 (Japan)

    2006-04-01

    Hydrogen (deuterium) passivation effects on carbon dangling bond defects accompanying a nearby hydrogen atom (H1') in boron-doped Cd homoepitaxial diamond films were investigated by electron paramagnetic resonance (EPR). Deuterium was incorporated into the films using microwave deuterium plasma at 673 K for 22 h. Incorporation of deuterium was confirmed by the passivation of boron acceptors. From the comparison of the EPR signal intensity before and after the deuterium plasma exposure, it was revealed that H1' could not be passivated by the present condition. From these, the high stability of H1' was indicated.

  6. 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

  7. Comparative study of the photocatalytic performance of boron-iron Co-doped and boron-doped TiO2 nanoparticles

    International Nuclear Information System (INIS)

    A series of nanosized boron-doped and boron-iron co-doped anatase TiO2 represented as Bx,Fey-TiO2 (x = 1, 3, 5, y = 0, 0.5, 1, 3, 5 in wt%) were synthesized by a modified sol-gel method, and characterized by various spectroscopic and analytical techniques. The presence of boron and/or iron causes a red shift in the absorption band of TiO2. The Bx,Fey-TiO2 systems are very effective catalysts for the degradation of toluene under UV or visible light. All reactions follow pseudo-first-order kinetics with the rate being a function of either the dopants or the light source (UV or visible light). The relative quantity and most importantly the position occupied by dopant were found to be the crucial factors in co-doping with respect to the properties and activity of the final product. In general, boron-doping enhances the reactivity while iron-doping works in an opposite manner, thus to show the following order of reactivity regardless of the light source: Bx-TiO2 > TiO2 > Bx,Fey-TiO2. Under the visible light, however, a reversal in this trend is made depending on the relative amount of iron. Thus, for instance, when y ≤ 5, the trend becomes as follows: Bx-TiO2 > Bx,Fey-TiO2 > TiO2

  8. 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

  9. Thin layer of ordered boron-doped TiO2 nanotubes fabricated in a novel type of electrolyte and characterized by remarkably improved photoactivity

    Science.gov (United States)

    Siuzdak, Katarzyna; Szkoda, Mariusz; Lisowska-Oleksiak, Anna; Grochowska, Katarzyna; Karczewski, Jakub; Ryl, Jacek

    2015-12-01

    This paper reports a novel method of boron doped titania nanotube arrays preparation by electrochemical anodization in electrolyte containing boron precursor - boron trifluoride diethyl etherate (BF3 C4H10O), simultaneously acting as an anodizing agent. A pure, ordered TiO2 nanotubes array, as a reference sample, was also prepared in solution containing a standard etching compound: ammonium fluoride. The doped and pure titania were characterized by scanning electron microscopy, UV-vis spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, photoluminescence emission spectroscopy and by means of electrochemical methods. The B-doping decidedly shifts the absorption edge of TiO2 nanotubes towards the visible light region and significantly inhibits the radiative recombination processes. Despite the fact that the doped sample is characterized by 4.6 lower real surface area when compared to pure titania, it leads to the decomposition of methylene blue in 93%, that is over 2.3 times higher than the degradation efficiency exhibited by the undoped material. The formation rate of hydroxyl radicals (rad OH) upon illumination significantly favours boron doped titania as a photocatalytic material. Moreover, the simple doping of TiO2 nanotubes array results in the enhancement of generated photocurrent from 120 μA/cm2 to 350 μA/cm2 registered for undoped and doped electrode, respectively.

  10. 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.

  11. Effect of deposition temperature on boron-doped carbon coatings deposited from a BCl3-C3H6-H2 mixture using low pressure chemical vapor deposition

    International Nuclear Information System (INIS)

    A mixture of propylene, hydrogen and boron trichloride was used to fabricate boron-doped carbon coatings by using low pressure chemical vapor deposition (LPCVD) technique. Effect of deposition temperature on deposition rate, morphologies, compositions and bonding states of boron-doped carbon coatings was investigated. Below 1273 K, the deposition rate is controlled by reaction dynamics. The deposition rate increases with increasing deposition temperature. The activation energy is 208.74 kJ/mol. Above 1273 K, the deposition rate decreases due to smaller critical radius rc and higher nuclei formation rate J with increasing temperature. Scanning electron microscopy shows that the structure changes from glass-like to nano-laminates with increasing deposition temperature. The boron concentration decreases with increasing deposition temperature, corresponding with increasing carbon concentration. The five types of bonding states are B-C, B-sub-C, BC2O, BCO2 and B-O. B-sub-C and BC2O are the main bonding states. The reactions are dominant at all temperatures, in which the B-sub-C and PyC are formed.

  12. 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.

  13. Diamond bio electronics.

    Science.gov (United States)

    Linares, Robert; Doering, Patrick; Linares, Bryant

    2009-01-01

    The use of diamond for advanced applications has been the dream of mankind for centuries. Until recently this dream has been realized only in the use of diamond for gemstones and abrasive applications where tons of diamonds are used on an annual basis. Diamond is the material system of choice for many applications, but its use has historically been limited due to the small size, high cost, and inconsistent (and typically poor) quality of available diamond materials until recently. The recent development of high quality, single crystal diamond crystal growth via the Chemical Vapor Deposition (CVD) process has allowed physcists and increasingly scientists in the life science area to think beyond these limitations and envision how diamond may be used in advanced applications ranging from quantum computing, to power generation and molecular imaging, and eventually even diamond nano-bots. Because of diamond's unique properties as a bio-compatible material, better understanding of diamond's quantum effects and a convergence of mass production, semiconductor-like fabrication process, diamond now promises a unique and powerful key to the realization of the bio-electronic devices being envisioned for the new era of medical science. The combination of robust in-the-body diamond based sensors, coupled with smart bio-functionalized diamond devices may lead to diamond being the platform of choice for bio-electronics. This generation of diamond based bio-electronic devices would contribute substantially to ushering in a paradigm shift for medical science, leading to vastly improved patient diagnosis, decrease of drug development costs and risks, and improved effectiveness of drug delivery and gene therapy programs through better timed and more customized solutions. PMID:19745488

  14. Heterogeneous distribution of exocytotic microdomains in adrenal chromaffin cells resolved by high-density diamond ultra-microelectrode arrays.

    Science.gov (United States)

    Gosso, Sara; Turturici, Marco; Franchino, Claudio; Colombo, Elisabetta; Pasquarelli, Alberto; Carbone, Emilio; Carabelli, Valentina

    2014-08-01

    Here we describe the ability of a high-density diamond microelectrode array targeted to resolve multi-site detection of fast exocytotic events from single cells. The array consists of nine boron-doped nanocrystalline diamond ultra-microelectrodes (9-Ch NCD-UMEA) radially distributed within a circular area of the dimensions of a single cell. The device can be operated in voltammetric or chronoamperometric configuration. Sensitivity to catecholamines, tested by dose-response calibrations, set the lowest detectable concentration of adrenaline to ∼5 μm. Catecholamine release from bovine or mouse chromaffin cells could be triggered by electrical stimulation or external KCl-enriched solutions. Spikes detected from the cell apex using carbon fibre microelectrodes showed an excellent correspondence with events measured at the bottom of the cell by the 9-Ch NCD-UMEA, confirming the ability of the array to resolve single quantal secretory events. Subcellular localization of exocytosis was provided by assigning each quantal event to one of the nine channels based on its location. The resulting mapping highlights the heterogeneous distribution of secretory activity in cell microdomains of 12-27 μm2. In bovine chromaffin cells, secretion was highly heterogeneous with zones of high and medium activity in 54% of the cell surface and zones of low or no activity in the remainder. The 'non-active' ('silent') zones covered 24% of the total and persisted for 6-8 min, indicating stable location. The 9-Ch NCD-UMEA therefore appears suitable for investigating the microdomain organization of neurosecretion with high spatial resolution. PMID:24879870

  15. 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

  16. Fast Block-match Motion Estimation Based on Multilevel Adaptive Diamond Search

    Science.gov (United States)

    Li, Shan; Yi, Qing-Ming; Shi, Min

    In this paper, a novel fast block-match algorithm called MADS based on multilevel adaptive diamond search is proposed. The algorithm adaptively estimates the frame-level motion complexity with the reference frame texture information and the macro-block residual value at first, and then estimates the block-level motion complexity according to the spatial-temporal correlation of the vector field. The threshold is applied to stop the stationary block from searching. The initial search point and different diamond search modes are adaptively selected based on motion type for non-stationary block. Experimental results show that MADS algorithm has better performance than other popular fast algorithms for a wide range of video sequences.

  17. Gas electron multiplier based on laser-perforated CVD diamond film: First tests

    CERN Document Server

    Franchino, S; Bolshakov, A; Ashkinazi, E; Kalkan, Y; Popovich, A; Komlenok, M; Sosnovtsev, V; Ralchenko, V

    2016-01-01

    Gas electron multiplier (GEM) is widely used in modern gas detectors of ionizing radiation in experiments on high-energy physics at accelerators and in other fields of science. Typically the GEM devices are based on a dielectric foil with holes and electrodes on both sides. GEMs made by radiation-hard dielectrics or wide band-gap semiconductors are desirable for some applications. The results of the first tests of the gas electron multiplier made of radiation-hard materials, such as polycrystalline CVD diamond with a thickness of 100 microns is described. Here we report on fabrication of GEM based on free-standing polycrystalline CVD diamond film and its first test.

  18. 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.

  19. On the recombination behaviour of iron in moderately boron-doped p-type silicon

    Science.gov (United States)

    Walz, D.; Joly, J.-P.; Kamarinos, G.

    1996-04-01

    The recombination lifetime and diffusion length of intentionally iron-contaminated samples were measured by the Surface Photo Voltage (SPV) and the Elymat technique. The lifetime results from these techniques for intentionally iron-contaminated samples were analysed, in particular for the aspect of the injection-level dependency of recombination lifetime. Based on theoretical considerations, a method for the analysis of deep-level parameters combining constant photon flux SPV and Elymat measurements has been developed. This method is based on a detailed numerical analysis of the Elymat technique, including the Dember electric field, the characteristics of the laser beam, the transport parameters of the semiconductor and multilevel Shockley-Read-Hall (SRH) recombination kinetics. The results of the numerical simulation are applied to the analysis of recombination lifetime measurements on intentionally iron-contaminated samples. We compared numerical simulations and experimental results from SPV and Elymat for p-type samples using the classical acceptor level at E v +0.1 eV and the donor level of FeB pairs at E c -0.3 eV as recombination centre. Better consistency in the interpretation of the results has been found in the doping range 1014 1016 cm-3 supposing the E c -0.3 eV level as predominant recombination centre. An attempt to extract the electron and hole capture cross-sections for this defect is made.

  20. Sensitivity of diamond-capped impedance transducer to Tröger’s base derivatives

    Czech Academy of Sciences Publication Activity Database

    Stehlík, Štěpán; Ižák, Tibor; Kromka, Alexander; Dolenský, B.; Havlík, M.; Rezek, Bohuslav

    2012-01-01

    Roč. 4, č. 8 (2012), s. 3860-3865. ISSN 1944-8244 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional research plan: CEZ:AV0Z10100521 Keywords : Tröger’s base derivative * nanocrystalline diamond * chemical sensor * impedance spectroscopy * surface conductivity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 5.008, year: 2012

  1. Competitive advantage of German renewable energy firms in Russsia: An empirical study based on Porter's diamond

    OpenAIRE

    Dögl, Corinna; Holtbrügge, Dirk

    2010-01-01

    This article analyzes the competitive advantage of German renewable energy firms in Russia. Based on Porter's diamond model of competitiveness, we examine the demand for renewable energy in Russia and German firms' ability to meet this demand. While the overall demand for renewable energy in Russia is still low, the study reveals formidable opportunities in the fields of biomass, solar and wind energy. Our findings are meant to address managers in the renewable energy industry and to aid poli...

  2. Wavelet-based fast time-resolved magnetic sensing with electronic spins in diamond

    OpenAIRE

    Xu, Nanyang; Jiang, Fengjian; Tian, Yu(School of Physics, University of Chinese Academy of Sciences, Beijing, 100049, China); Ye, Jianfeng; Shi, Fazhan; Lv, Haijiang; Wang, Ya; Wrachtrup, Jorg; Du, Jiangfeng

    2015-01-01

    Time-resolved magnetic sensing is of great importance from fundamental studies to applications in physical and biological sciences. Recently the nitrogen-vacancy (NV) defect center in diamond has been developed as a promising sensor of magnetic field under ambient conditions. However the methods to reconstruct time-resolved magnetic field with high sensitivity are not yet fully developed. Here, we propose and demonstrate a novel sensing method based on spin echo, and Haar wavelet transform. O...

  3. Anodic oxidation of benzoquinone using diamond anode.

    Science.gov (United States)

    Panizza, Marco

    2014-01-01

    The anodic degradation of 1,4-benzoquinone (BQ), one of the most toxic xenobiotic, was investigated by electrochemical oxidation at boron-doped diamond anode. The electrolyses have been performed in a single-compartment flow cell in galvanostatic conditions. The influence of applied current (0.5-2 A), BQ concentration (1-2 g dm(-3)), temperature (20-45 °C) and flow rate (100-300 dm(3) h(-1)) has been studied. BQ decay kinetic, the evolution of its oxidation intermediates and the mineralization of the aqueous solutions were monitored during the electrolysis by high-performance liquid chromatograph (HPLC) and chemical oxygen demand (COD) measurements. The results obtained show that the use of diamond anode leads to total mineralization of BQ in any experimental conditions due to the production of oxidant hydroxyl radicals electrogenerated from water discharge. The decay kinetics of BQ removal follows a pseudo-first-order reaction, and the rate constant increases with rising current density. The COD removal rate was favoured by increasing of applied current, recirculating flow rate and it is almost unaffected by solution temperature. PMID:24710725

  4. 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.

  5. Electroless oxidation of diamond surfaces in ceric and ferricyanide solutions: An easy way to produce 'C-O' functional groups

    International Nuclear Information System (INIS)

    Despite many works are devoted to oxidation of diamond surfaces, it is still a challenge, to successfully produce well defined 'C-O' functions, particularly for functionalization purposes. In this paper we describe and compare, for the first time, the 'electroless' oxidation of as-deposited polycrystalline boron-doped diamond (BDD) films in ceric and ferricyanide solutions at room temperature. Both reactions efficiently generate oxygen functionalities on BDD surface. While a higher amount of 'C-O' moieties is produced with Ce4+ as oxidizing agent, the use of ferricyanide specie seems the most interesting to specifically generate hydroxyl groups. Additionally, this easy to perform oxidative method appears not damaging for diamond surfaces and adapted to conductive or non-conductive materials. The resulting surfaces were characterized using X-ray photoelectron spectroscopy, contact angle and capacitance-voltage analysis.

  6. Performance and perspectives of the diamond based Beam Condition Monitor for beam loss monitoring at CMS

    CERN Document Server

    AUTHOR|(CDS)2080862

    2015-01-01

    At CMS, a beam loss monitoring system is operated to protect the silicon detectors from high particle rates, arising from intense beam loss events. As detectors, poly-crystalline CVD diamond sensors are placed around the beam pipe at several locations inside CMS. In case of extremely high detector currents, the LHC beams are automatically extracted from the LHC rings.Diamond is the detector material of choice due to its radiation hardness. Predictions of the detector lifetime were made based on FLUKA monte-carlo simulations and irradiation test results from the RD42 collaboration, which attested no significant radiation damage over several years.During the LHC operational Run1 (2010 â?? 2013), the detector efficiencies were monitored. A signal decrease of about 50 times stronger than expectations was observed in the in-situ radiation environment. Electric field deformations due to charge carriers, trapped in radiation induced lattice defects, are responsible for this signal decrease. This so-called polarizat...

  7. Investigation of Injection Losses at the Large Hadron Collider with Diamond Based Particle Detectors

    CERN Document Server

    Stein, Oliver; Burkart, Florian; Dehning, Bernd; Griesmayer, Erich; Kain, Verena; Schmidt, Ruediger; Wollmann, Daniel

    2016-01-01

    During the operation of the Large Hadron Collider (LHC) in 2015, increased injection losses were observed. To minimize stress on accelerator components in the injection regions of the LHC and to guarantee an efficient operation these losses needed to be understood and possible mitigation techniques should be studied. Measurements with diamond particle detectors revealed the loss structure with ns-resolution for the first time. Based on these measurements, recaptured beam from the Super Proton Synchrotron (SPS) surrounding the nominal bunch train was identified as the major contributor to the injection loss signals. Methods to reduce the recaptured beam in the SPS were successfully tested and verified with the diamond particle detectors. In this paper the detection and classification of LHC injection losses are described. The methods to reduce these losses and verification measurements are presented and discussed.

  8. Synthesis of platinum and platinum–ruthenium-modified diamond nanoparticles

    International Nuclear Information System (INIS)

    With the aim of developing dimensionally stable-supported catalysts for direct methanol fuel cell application, Pt and Pt–Ru catalyst nanoparticles were deposited onto undoped and boron-doped diamond nanoparticles (BDDNPs) through a chemical reduction route using sodium borohydride as a reducing agent. As-received commercial diamond nanoparticles (DNPs) were purified by refluxing in aqueous nitric acid solution. Prompt gamma neutron activation analysis and transmission electron microscopy (TEM) techniques were employed to characterize the as-received and purified DNPs. The purified diamond nanoparticulates, as well as the supported Pt and Pt–Ru catalyst systems, were subjected to various physicochemical characterizations, such as scanning electron microscopy, energy dispersive analysis, TEM, X-ray diffraction, inductively coupled plasma-mass spectrometry, X-ray photoelectron spectroscopy, and infrared spectroscopy. Physicochemical characterization showed that the sizes of Pt and Pt–Ru particles were only a few nanometers (2–5 nm), and they were homogeneously dispersed on the diamond surface (5–10 nm). The chemical reduction method offers a simple route to prepare the well-dispersed Pt and Pt–Ru catalyst nanoparticulates on undoped and BDDNPs for their possible employment as an advanced electrode material in direct methanol fuel cells.

  9. Test of a prototype neutron spectrometer based on diamond detectors in a fast reactor

    CERN Document Server

    Osipenko, M; Ripani, M; Pillon, M; Ricco, G; Caiffi, B; Cardarelli, R; Verona-Rinati, G; Argiro, S

    2015-01-01

    A prototype of neutron spectrometer based on diamond detectors has been developed. This prototype consists of a $^6$Li neutron converter sandwiched between two CVD diamond crystals. The radiation hardness of the diamond crystals makes it suitable for applications in low power research reactors, while a low sensitivity to gamma rays and low leakage current of the detector permit to reach good energy resolution. A fast coincidence between two crystals is used to reject background. The detector was read out using two different electronic chains connected to it by a few meters of cable. The first chain was based on conventional charge-sensitive amplifiers, the other used a custom fast charge amplifier developed for this purpose. The prototype has been tested at various neutron sources and showed its practicability. In particular, the detector was calibrated in a TRIGA thermal reactor (LENA laboratory, University of Pavia) with neutron fluxes of $10^8$ n/cm$^2$s and at the 3 MeV D-D monochromatic neutron source na...

  10. A First Principles study on Boron-doped Graphene decorated by Ni-Ti-Mg atoms for Enhanced Hydrogen Storage Performance

    Science.gov (United States)

    Nachimuthu, Santhanamoorthi; Lai, Po-Jung; Leggesse, Ermias Girma; Jiang, Jyh-Chiang

    2015-11-01

    We proposed a new solid state material for hydrogen storage, which consists of a combination of both transition and alkaline earth metal atoms decorating a boron-doped graphene surface. Hydrogen adsorption and desorption on this material was investigated using density functional theory calculations. We find that the diffusion barriers for H atom migration and desorption energies are lower than for the previously designed mediums and the proposed medium can reach the gravimetric capacity of ~6.5 wt % hydrogen, which is much higher than the DOE target for the year 2015. Molecular Dynamics simulations show that metal atoms are stably adsorbed on the B doped graphene surface without clustering, which will enhance the hydrogen storage capacity.

  11. Optical engineering of diamond

    CERN Document Server

    Rabeau, James R

    2013-01-01

    This is the first comprehensive book on the engineering of diamond optical devices. It will give readers an up-to-date account of the properties of optical quality synthetic diamond (single crystal, nanodiamond and polycrystalline) and reviews the large and growing field of engineering of diamond-based optical devices, with applications in quantum computation, nano-imaging, high performance lasers, and biomedicine. It aims to provide scientists, engineers and physicists with a valuable resource and reference book for the design and performance of diamond-based optical devices.

  12. 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

  13. Microwave activation of electrochemical processes: High temperature phenol and triclosan electro-oxidation at carbon and diamond electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Ghanem, Mohamed A.; Marken, Frank [Department of Chemistry, University of Bath, Bath BA2 7AY (United Kingdom); Compton, Richard G.; Coles, Barry A. [Physical and Theoretical Chemistry Laboratory, Oxford University, Oxford OX1 3QZ (United Kingdom); Psillakis, Elefteria [Laboratory of Aquatic Chemistry, Department of Environmental Engineering, Technical University of Crete, Polytechnioupolis, 73100 Chania-Crete (Greece); Kulandainathan, M. Anbu [Central Electrochemical Research Institute, Karaikudi (India)

    2007-12-20

    The electrochemical oxidation of phenolic compounds in aqueous media is known to be affected by the formation of electro-polymerized organic layers which lead to partial or complete electrode blocking. In this study the effect of high intensity microwave radiation applied locally at the electrode surface is investigated for the oxidation of phenol and triclosan in alkaline solution at a 500 {mu}m diameter glassy carbon or at a 500 {mu}m x 500 {mu}m boron-doped diamond electrode. The temperature at the electrode surface and mass transport enhancement are determined by calibration with the Fe(CN){sub 6}{sup 3-/4-} redox system in aqueous 0.3 M NaOH and 0.2 NaCl (pH 12) solution. The calibration shows that strong thermal and mass transport effects occur at both glassy carbon and boron-doped diamond electrodes. The average electrode temperature reaches up to 390 K and mass transport enhancements of more than 20-fold are possible. For the phenol electro-oxidation at glassy carbon electrodes and at a concentration below 2 mM a multi-electron oxidation (ca. 4 electrons) occurs in the presence of microwave radiation. For the electro-oxidation of the more hydrophobic triclosan only the one-electron oxidation occurs. Although currents are enhanced in presence of microwave radiation, rapid blocking of the electrode surface in particular at high phenol concentrations still occurs. (author)

  14. Microwave activation of electrochemical processes: High temperature phenol and triclosan electro-oxidation at carbon and diamond electrodes

    International Nuclear Information System (INIS)

    The electrochemical oxidation of phenolic compounds in aqueous media is known to be affected by the formation of electro-polymerized organic layers which lead to partial or complete electrode blocking. In this study the effect of high intensity microwave radiation applied locally at the electrode surface is investigated for the oxidation of phenol and triclosan in alkaline solution at a 500 μm diameter glassy carbon or at a 500 μm x 500 μm boron-doped diamond electrode. The temperature at the electrode surface and mass transport enhancement are determined by calibration with the Fe(CN)63-/4- redox system in aqueous 0.3 M NaOH and 0.2 NaCl (pH 12) solution. The calibration shows that strong thermal and mass transport effects occur at both glassy carbon and boron-doped diamond electrodes. The average electrode temperature reaches up to 390 K and mass transport enhancements of more than 20-fold are possible. For the phenol electro-oxidation at glassy carbon electrodes and at a concentration below 2 mM a multi-electron oxidation (ca. 4 electrons) occurs in the presence of microwave radiation. For the electro-oxidation of the more hydrophobic triclosan only the one-electron oxidation occurs. Although currents are enhanced in presence of microwave radiation, rapid blocking of the electrode surface in particular at high phenol concentrations still occurs

  15. 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

  16. Electrochemical measurements of serotonin (5-HT) release from the guinea pig mucosa using continuous amperometry with a boron-doped diamond microelectrode

    OpenAIRE

    Zhao, Hong; Bian, Xiaochun; Galligan, James J.; Swain, Greg M.

    2010-01-01

    Irritable bowel syndrome (IBS) is a common gastrointestinal (GI) disorder characterized by chronic abdominal discomfort, including pain, bloating and changes in bowel habits. The exact cause of IBS is not entirely understood. Recent studies have shown that IBS may be associated with altered serotonin (5-hydroxytryptamine, 5-HT) levels within the GI tract. About 90% of 5-HT in the human body is produced and stored in enterochromaffin (EC) cells that reside in the mucosal layer of the intestine...

  17. Influence of chloride-mediated oxidation on the electrochemical degradation of the direct black 22 dye using boron-doped diamond and β-PbO2 anodes

    OpenAIRE

    Douglas A. C. Coledam; José M. Aquino; Romeu C. Rocha-Filho; Nerilso Bocchi; Sonia R. Biaggio

    2014-01-01

    The Direct Black 22 dye was electrooxidized at 30 mA cm-2 in a flow cell using a BDD or β-PbO2 anode, varying pH (3, 7, 11), temperature (10, 25, 45 °C), and [NaCl] (0 or 1.5 g L-1). In the presence of NaCl, decolorization rates were similar for all conditions investigated, but much higher than predicted through a theoretical model assuming mass-transport control; similar behavior was observed for COD removal (at pH 7, 25 °C), independently of the anode. With no NaCl, COD removals were also h...

  18. Wirelessly Powered High-Temperature Strain Measuring Probe Based on Piezoresistive Nanocrystalline Diamond Layers

    Directory of Open Access Journals (Sweden)

    Bouřa Adam

    2016-09-01

    Full Text Available A high-temperature piezo-resistive nano-crystalline diamond strain sensor and wireless powering are presented in this paper. High-temperature sensors and electronic devices are required in harsh environments where the use of conventional electronic circuits is impractical or impossible. Piezo-resistive sensors based on nano-crystalline diamond layers were successfully designed, fabricated and tested. The fabricated sensors are able to operate at temperatures of up to 250°C with a reasonable sensitivity. The basic principles and applicability of wireless powering using the near magnetic field are also presented. The system is intended mainly for circuits demanding energy consumption, such as resistive sensors or devices that consist of discrete components. The paper is focused on the practical aspect and implementation of the wireless powering. The presented equations enable to fit the frequency to the optimal range and to maximize the energy and voltage transfer with respect to the coils’ properties, expected load and given geometry. The developed system uses both high-temperature active devices based on CMOS-SOI technology and strain sensors which can be wirelessly powered from a distance of up to several centimetres with the power consumption reaching hundreds of milliwatts at 200°C. The theoretical calculations are based on the general circuit theory and were performed in the software package Maple. The results were simulated in the Spice software and verified on a real sample of the measuring probe.

  19. Diamond Pixel Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Adam, W.; Berdermann, E.; Bergonzo, P.; Bertuccio, G.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; D' Angelo, P.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Doroshenko, J.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foster, J.; Foulon, F.; Friedl, M.; Gan, K.K.; Gheeraert, E.; Gobbi, B.; Grim, G.P.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Koeth, T.; Krammer, M.; Lander, R.; Logiudice, A.; Lu, R.; Lynne, L.M.; Manfredotti, C.; Meier, D.; Mishina, M.; Moroni, L.; Oh, A.; Pan, L.S.; Pernicka, M.; Perera, L. E-mail: perera@physics.rutgers.edu; Pirollo, S.; Plano, R.; Procario, M.; Riester, J.L.; Roe, S.; Rott, C.; Rousseau, L.; Rudge, A.; Russ, J.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Suter, B.; Tapper, R.J.; Tesarek, R.; Trischuk, W.; Tromson, D.; Vittone, E.; Wedenig, R.; Weilhammer, P.; White, C.; Zeuner, W.; Zoeller, M

    2001-06-01

    Diamond based pixel detectors are a promising radiation-hard technology for use at the LHC. We present first results on a CMS diamond pixel sensor. With a threshold setting of 2000 electrons, an average pixel efficiency of 78% was obtained for normally incident minimum ionizing particles.

  20. Diamond pixel detectors

    CERN Document Server

    Adam, W; Bergonzo, P; Bertuccio, G; Bognai, F; Borchi, E; Brambilla, A; Bruzzi, Mara; Colledani, C; Conway, J; D'Angelo, P; Dabrowski, W; Delpierre, P A; Deneuville, A; Doroshenko, J; Dulinski, W; van Eijk, B; Fallou, A; Fizzotti, F; Foster, J; Foulon, F; Friedl, M; Gan, K K; Gheeraert, E; Gobbi, B; Grim, G P; Hallewell, G D; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Kagan, H; Kania, D R; Kaplon, J; Kass, R; Koeth, T W; Krammer, Manfred; Lander, R; Lo Giudice, A; Lü, R; MacLynne, L; Manfredotti, C; Meier, D; Mishina, M; Moroni, L; Oh, A; Pan, L S; Pernicka, Manfred; Perera, L P; Pirollo, S; Plano, R; Procario, M; Riester, J L; Roe, S; Rott, C; Rousseau, L; Rudge, A; Russ, J; Sala, S; Sampietro, M; Schnetzer, S; Sciortino, S; Stelzer, H; Stone, R; Suter, B; Tapper, R J; Tesarek, R; Trischuk, W; Tromson, D; Vittone, E; Wedenig, R; Weilhammer, Peter; White, C; Zeuner, W; Zöller, M

    2001-01-01

    Diamond based pixel detectors are a promising radiation-hard technology for use at the LHC. We present first results on a CMS diamond pixel sensor. With a threshold setting of 2000 electrons, an average pixel efficiency of 78% was obtained for normally incident minimum ionizing particles. (3 refs).

  1. Diamond Pixel Detectors

    International Nuclear Information System (INIS)

    Diamond based pixel detectors are a promising radiation-hard technology for use at the LHC. We present first results on a CMS diamond pixel sensor. With a threshold setting of 2000 electrons, an average pixel efficiency of 78% was obtained for normally incident minimum ionizing particles

  2. 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...

  3. New Diamond Block Based Gradient Descent Search Algorithm for Motion Estimation in the MPEG-4 Encoder

    Institute of Scientific and Technical Information of China (English)

    王振洲; 李桂苓

    2003-01-01

    Motion estimation is an important part of the MPEG-4 encoder, due to its significant impact on the bit rate and the output quality of the encoder sequence. Unfortunately this feature takes a significant part of the encoding time especially when the straightforward full search(FS) algorithm is used. In this paper, a new algorithm named diamond block based gradient descent search (DBBGDS) algorithm, which is significantly faster than FS and gives similar quality of the output sequence, is proposed. At the same time, some other algorithms, such as three step search (TSS), improved three step search (ITSS), new three step search (NTSS), four step search (4SS), cellular search (CS) , diamond search (DS) and block based gradient descent search (BBGDS), are adopted and compared with DBBGDS. As the experimental results show, DBBGDS has its own advantages. Although DS has been adopted by the MPEG-4 VM, its output sequence quality is worse than that of the proposed algorithm while its complexity is similar to the proposed one. Compared with BBGDS, the proposed algorithm can achieve a better output quality.

  4. Effects of Rare Earth and Hot Pressing Sintering Temperature on the Transverse Rupture Strength of Fe-based Diamond Composites

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Effects of sintering temperature in hot pressing, t yp es, states and amounts of rare earth as well as TiH 2 on the transverse rupture strength (TRS) of Fe-based composites are studied by means of orthogonal test and variance analysis in this paper. It is found that sintering temperature has a significant effect on the TRS of Fe-based diamond composites. The optimal sin tering temperature is 780~860 ℃. On the contrary, the effects of RE additi v es on values of TRS of the diamond composites have on di...

  5. Presentation of a research project addressed to the realisation of a diamond-based cellular biosensing device

    Science.gov (United States)

    Boarino, Luca; Carabelli, Valentina; Carbone, Emilio; Genovese, Marco; Gosso, Sara; Olivero, Paolo; Pasquarelli, Alberto; Picollo, Federico; Traina, Paolo

    2012-02-01

    In this proceedings we will present a research project financed by Piedmont regional government (Italy; finalized to the realization and commercialization of functional devices for cellular bio-sensing based on diamond. Partners of the project are: Crisel Instruments, Torino University, Torino Polytechnic, INRIM, Politronica, Bionica Tech, Ulm University Here the main features of the final devices will be briefly summarized. We envisage an active diamond-based cellular substrate that can simultaneously stimulate and detect a variety of signals (chemical, optical, electrical) to and from neuroendocrine cells, in a fully biocompatible environment for the cellular system under test. Such a device can be realized by fully exploiting the peculiar properties of diamond: optical transparency, biocompatibility, chemical inertness, accessibility to a conductive graphite-like phase; properties that will be further explored and tested during the project.

  6. Diamond photonics

    Science.gov (United States)

    Aharonovich, Igor; Greentree, Andrew D.; Prawer, Steven

    2011-07-01

    Diamond, a material marvelled for its strength, beauty and perfection, was first used to polish stone axes in Neolithic times. This most ancient of materials is now being touted by many as the ideal platform for quantum-age technologies. In this Review, we describe how the properties of diamond match the requirements of the 'second quantum revolution'. We also discuss recent progress in the development of diamond -- and particularly diamond colour centres -- for transforming quantum information science into practical quantum information technology.

  7. Characterization of the Diamond-like Carbon Based Functionally Gradient Film

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Diamond-like carbon coatings have been used as solid lubricating coatings in vacuum technology for their goodphysical and chemical properties. In this paper, the hybrid technique of unbalanced magnetron sputtering and plasmaimmersion ion implantation (PIll) was adopted to fabricate diamond-like carbon-based functionally gradient film,N/TiN/Ti(N,C)/DLC, on the 304 stainless steel substrate. The film was characterized by using Raman spectroscopyand glancing X-ray diffraction (GXRD), and the topography and surface roughness of the film was observed usingAFM. The mechanical properties of the film were evaluated by nano-indentation. The results showed that the surfaceroughness of the film was approximately 0.732 nm. The hardness and elastic modulus, fracture toughness andinterfacial fracture toughness of N/TiN/Ti(N,C)/DLC functionally gradient film were about 19.84 GPa, 190.03 GPa,3.75 MPa.m1/2 and 5.68 MPa@m1/2, respectively. Compared with that of DLC monolayer and C/TiC/DLC multilayer,this DLC gradient film has better qualities as a solid lubricating coating.

  8. A stacking-fault based microscopic model for platelets in diamond

    Science.gov (United States)

    Antonelli, Alex; Nunes, Ricardo

    2005-03-01

    We propose a new microscopic model for the 001 planar defects in diamond commonly called platelets. This model is based on the formation of a metastable stacking fault, which can occur because of the ability of carbon to stabilize in different bonding configurations. In our model the core of the planar defect is basically a double layer of three-fold coordinated sp^2 carbon atoms embedded in the common sp^3 diamond structure. The properties of the model were determined using ab initio total energy calculations. All significant experimental signatures attributed to the platelets, namely, the lattice displacement along the [001] direction, the asymmetry between the [110] and the [11 0] directions, the infrared absorption peak B^' , and broad luminescence lines that indicate the introduction of levels in the band gap, are naturally accounted for in our model. The model is also very appealing from the point of view of kinetics, since naturally occurring shearing processes will lead to the formation of the metastable fault.Authors acknowledge financial support from the Brazilian agencies FAPESP, CNPq, FAEP-UNICAMP, FAPEMIG, and Instituto do Milênio em Nanociências-MCT

  9. Diamond identifaction

    International Nuclear Information System (INIS)

    X-ray topography on diamonds allows for unique identification of diamonds. The method described consists of the registration of crystal defects, inclusions etc. of a diamond, resulting in a 'finger print' of the individual jewel which can only be changed by its complete destruction

  10. Microcrystalline diamond cylindrical resonators with quality-factor up to 0.5 million

    International Nuclear Information System (INIS)

    We demonstrate high quality-factor 1.5 mm diameter batch-fabricated microcrystalline diamond cylindrical resonators (CR) with quality-factors limited by thermoelastic damping (TED) and surface loss. Resonators were fabricated 2.6 and 5.3 μm thick in-situ boron-doped microcrystalline diamond films deposited using hot filament chemical vapor deposition. The quality-factor (Q) of as-fabricated CR's was found to increase with the resonator diameter and diamond thickness. Annealing the CRs at 700 °C in a nitrogen atmosphere led to a three-fold increase in Q, a result we attribute to thinning of the diamond layer via reaction with residual O2 in the annealing furnace. Post-anneal Q exceeding 0.5 million (528 000) was measured at the 19 kHz elliptical wineglass modes, producing a ring-down time of 8.9 s. A model for Q versus diamond thickness and resonance frequency is developed including the effects of TED and surface loss. Measured quality factors are shown to agree with the predictions of this model

  11. Diamond and Hydrogenated Carbons for Advanced Batteries and Fuel Cells: Fundamental Studies and Applications.

    Energy Technology Data Exchange (ETDEWEB)

    Swain; Greg M.

    2009-04-13

    The original funding under this project number was awarded for a period 12/1999 until 12/2002 under the project title Diamond and Hydrogenated Carbons for Advanced Batteries and Fuel Cells: Fundamental Studies and Applications. The project was extended until 06/2003 at which time a renewal proposal was awarded for a period 06/2003 until 06/2008 under the project title Metal/Diamond Composite Thin-Film Electrodes: New Carbon Supported Catalytic Electrodes. The work under DE-FG02-01ER15120 was initiated about the time the PI moved his research group from the Department of Chemistry at Utah State University to the Department of Chemistry at Michigan State University. This DOE-funded research 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.

  12. All-Diamond Microelectrodes as Solid State Probes for Localized Electrochemical Sensing.

    Science.gov (United States)

    Silva, Eduardo L; Gouvêa, Cristol P; Quevedo, Marcela C; Neto, Miguel A; Archanjo, Braulio S; Fernandes, António J S; Achete, Carlos A; Silva, Rui F; Zheludkevich, Mikhail L; Oliveira, Filipe J

    2015-07-01

    The fabrication of an all-diamond microprobe is demonstrated for the first time. This ME (microelectrode) assembly consists of an inner boron doped diamond (BDD) layer and an outer undoped diamond layer. Both layers were grown on a sharp tungsten tip by chemical vapor deposition (CVD) in a stepwise manner within a single deposition run. BDD is a material with proven potential as an electrochemical sensor. Undoped CVD diamond is an insulating material with superior chemical stability in comparison to conventional insulators. Focused ion beam (FIB) cutting of the apex of the ME was used to expose an electroactive BDD disk. By cyclic voltammetry, the redox reaction of ferrocenemethanol was shown to take place at the BDD microdisk surface. In order to ensure that the outer layer was nonelectrically conductive, a diffusion barrier for boron atoms was established seeking the formation of boron-hydrogen complexes at the interface between the doped and the undoped diamond layers. The applicability of the microelectrodes in localized corrosion was demonstrated by scanning amperometric measurements of oxygen distribution above an Al-Cu-CFRP (Carbon Fiber Reinforced Polymer) galvanic corrosion cell. PMID:26057348

  13. Microcrystalline diamond cylindrical resonators with quality-factor up to 0.5 million

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Daisuke; Yang, Chen; Lin, Liwei [Department of Mechanical Engineering, University of California, Berkeley, California 94720 (United States); Heidari, Amir [Department of Mechanical and Aerospace Engineering, University of California, Davis, California 95616 (United States); Najar, Hadi [Department of Electrical and Computer Engineering, University of California, Davis, California 95616 (United States); Horsley, David A. [Department of Mechanical and Aerospace Engineering, University of California, Davis, California 95616 (United States); Department of Electrical and Computer Engineering, University of California, Davis, California 95616 (United States)

    2016-02-01

    We demonstrate high quality-factor 1.5 mm diameter batch-fabricated microcrystalline diamond cylindrical resonators (CR) with quality-factors limited by thermoelastic damping (TED) and surface loss. Resonators were fabricated 2.6 and 5.3 μm thick in-situ boron-doped microcrystalline diamond films deposited using hot filament chemical vapor deposition. The quality-factor (Q) of as-fabricated CR's was found to increase with the resonator diameter and diamond thickness. Annealing the CRs at 700 °C in a nitrogen atmosphere led to a three-fold increase in Q, a result we attribute to thinning of the diamond layer via reaction with residual O{sub 2} in the annealing furnace. Post-anneal Q exceeding 0.5 million (528 000) was measured at the 19 kHz elliptical wineglass modes, producing a ring-down time of 8.9 s. A model for Q versus diamond thickness and resonance frequency is developed including the effects of TED and surface loss. Measured quality factors are shown to agree with the predictions of this model.

  14. Deep levels in CVD diamond and their influence on the electronic properties of diamond-based radiation sensors

    Energy Technology Data Exchange (ETDEWEB)

    Bruzzi, M.; Lagomarsino, S.; Menichelli, D.; Miglio, S.; Pini, S.; Sciortino, S. [Dipartimento di Energetica, Via S. Marta 3, 50139 Firenze (Italy); INFN, Sezione di Firenze (Italy); INFM, Sezione di Firenze (Italy); Bucciolini, M. [Dipartimento di Fisiopatologia Clinica, Firenze (Italy); INFN, Sezione di Firenze (Italy); Scaringella, M. [Dipartimento di Energetica, Via S. Marta 3, 50139 Firenze (Italy)

    2002-10-16

    Deep levels in undoped chemical vapor deposited (CVD) diamond films have been characterized by thermally stimulated current spectroscopy (TSC) in the range of 300-650 K. The TSC results have been tentatively correlated to the performance of the samples as on-line dosimeters and particle detectors. The TSC signal is dominated by a set of deep levels with an activation energy in the range of 1.0-1.4 eV. The trapping activity of these levels, which can be related to grain boundaries, strongly influences the detector performance at room temperature. After neutron irradiation up to the fluence of 2 x 10{sup 15} n/cm{sup 2} the amplitude of the TSC signal decreases of about one order of magnitude, the pumping effect becomes significantly less pronounced and the charge collection efficiency decreases of about 30%. Thus, the radiation-induced removal of these deep levels must be accompanied by the creation of other traps, probably vacancy-related and not visible by TSC in this temperature range, which have little effect on the dynamic response of the device but can affect the charge collection efficiency. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  15. Deep levels in CVD diamond and their influence on the electronic properties of diamond-based radiation sensors

    International Nuclear Information System (INIS)

    Deep levels in undoped chemical vapor deposited (CVD) diamond films have been characterized by thermally stimulated current spectroscopy (TSC) in the range of 300-650 K. The TSC results have been tentatively correlated to the performance of the samples as on-line dosimeters and particle detectors. The TSC signal is dominated by a set of deep levels with an activation energy in the range of 1.0-1.4 eV. The trapping activity of these levels, which can be related to grain boundaries, strongly influences the detector performance at room temperature. After neutron irradiation up to the fluence of 2 x 1015 n/cm2 the amplitude of the TSC signal decreases of about one order of magnitude, the pumping effect becomes significantly less pronounced and the charge collection efficiency decreases of about 30%. Thus, the radiation-induced removal of these deep levels must be accompanied by the creation of other traps, probably vacancy-related and not visible by TSC in this temperature range, which have little effect on the dynamic response of the device but can affect the charge collection efficiency. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  16. STABLE DIAMOND GRINDING

    Directory of Open Access Journals (Sweden)

    Yury Gutsalenko

    2010-06-01

    Full Text Available The paper generalizes on the one hand theory of kinematic-geometrical simulation of grinding processes by means of tools with working part as binding matrix with abrasive grains located in it in random manner, for example diamond grains, and on the other hand practical performance of combined grinding process, based on introduction of additional energy as electric discharges and called by the organization-developer (Kharkov Polytechnic Institute «diamond-spark grinding» as applied to processing by means of diamond wheel. Implementation of diamond-spark grinding technologies on the basis of developed generalized theoretical approach allows to use the tool with prescribed tool-life, moreover to make the most efficient use of it up to full exhausting of tool-life, determined by diamond-bearing thickness. Development is directed forward computer-aided manufacturing.

  17. Nanofocusing of hard X-ray free electron laser pulses using diamond based Fresnel zone plates

    Science.gov (United States)

    David, C.; Gorelick, S.; Rutishauser, S.; Krzywinski, J.; Vila-Comamala, J.; Guzenko, V. A.; Bunk, O.; Färm, E.; Ritala, M.; Cammarata, M.; Fritz, D. M.; Barrett, R.; Samoylova, L.; Grünert, J.; Sinn, H.

    2011-08-01

    A growing number of X-ray sources based on the free-electron laser (XFEL) principle are presently under construction or have recently started operation. The intense, ultrashort pulses of these sources will enable new insights in many different fields of science. A key problem is to provide x-ray optical elements capable of collecting the largest possible fraction of the radiation and to focus into the smallest possible focus. As a key step towards this goal, we demonstrate here the first nanofocusing of hard XFEL pulses. We developed diamond based Fresnel zone plates capable of withstanding the full beam of the world's most powerful x-ray laser. Using an imprint technique, we measured the focal spot size, which was limited to 320 nm FWHM by the spectral band width of the source. A peak power density in the focal spot of 4×1017 W/cm2 was obtained at 70 fs pulse length.

  18. Method to fabricate portable electron source based on nitrogen incorporated ultrananocrystalline diamond (N-UNCD)

    Energy Technology Data Exchange (ETDEWEB)

    Sumant, Anirudha V.; Divan, Ralu; Posada, Chrystian M.; Castano, Carlos H.; Grant, Edwin J.; Lee, Hyoung K.

    2016-03-29

    A source cold cathode field emission array (FEA) source based on ultra-nanocrystalline diamond (UNCD) field emitters. This system was constructed as an alternative for detection of obscured objects and material. Depending on the geometry of the given situation a flat-panel source can be used in tomography, radiography, or tomosynthesis. Furthermore, the unit can be used as a portable electron or X-ray scanner or an integral part of an existing detection system. UNCD field emitters show great field emission output and can be deposited over large areas as the case with carbon nanotube "forest" (CNT) cathodes. Furthermore, UNCDs have better mechanical and thermal properties as compared to CNT tips which further extend the lifetime of UNCD based FEA.

  19. Development of an Amorphous Selenium-Based Photodetector Driven by a Diamond Cold Cathode

    Directory of Open Access Journals (Sweden)

    Tatsuo Shimosawa

    2013-10-01

    Full Text Available Amorphous-selenium (a-Se based photodetectors are promising candidates for imaging devices, due to their high spatial resolution and response speed, as well as extremely high sensitivity enhanced by an internal carrier multiplication. In addition, a-Se is reported to show sensitivity against wide variety of wavelengths, including visible, UV and X-ray, where a-Se based flat-panel X-ray detector was proposed. In order to develop an ultra high-sensitivity photodetector with a wide detectable wavelength range, a photodetector was fabricated using a-Se photoconductor and a nitrogen-doped diamond cold cathode. In the study, a prototype photodetector has been developed, and its response to visible and ultraviolet light are characterized.

  20. Micro Extrinsic Fiber-Optic Fabry-Perot Interferometric Sensor Based on Erbium- and Boron-Doped Fibers

    International Nuclear Information System (INIS)

    Micro extrinsic Fabry–Perot interferometers (MEFPIs), with cavity lengths of up to ∼ 9 μm and maximum fringe contrast of ∼ 19 dB, are fabricated by chemically etching Er- and B-doped optical fibers and then splicing the etched fiber to a single-mode fiber, for the first time to the best of our knowledge. The strain and temperature responses of the MEFPI sensors are investigated experimentally. Good linearity and high sensitivity are achieved. Such a type of MEFPI sensor is cost-effective and suitable for mass production, indicating its great potential for a wide range of applications. (fundamental areas of phenomenology(including applications))

  1. Ag Nanoparticles on Boron Doped Multi-walled Carbon Nanotubes as a Synergistic Catalysts for Oxygen Reduction Reaction in Alkaline Media

    International Nuclear Information System (INIS)

    Highlights: • The mass activity of Ag/B-MWCNTs reduces with increasing of Ag loading. • The B-MWCNTs can be a promising supporting material for low-cost ORR catalyst. • This work the role of supporting materials in reducing the loading of metal catalyst. - Abstract: Here we report the oxygen reduction reaction (ORR) activity of Ag nanoparticles supported on boron doped multi-walled carbon nanotubes (Ag/B-MWCNTs) with different Ag loadings synthesized by a facile chemical method. Transmission electron microscopy (TEM) and X-ray diffraction patterns (XRD) measurements were employed to investigate the morphology and crystal structure of the as-prepared catalysts. The electrochemical results demonstrated that all the Ag/B-MWCNTs samples catalyzed the ORR in alkaline media by an efficient four-electron pathway. Furthermore, Ag/B-MWCNTs with lowest Ag loading (20%) performed the highest mass activity towards ORR mainly due to the synergistic effect of Ag nanoparticles and B-MWCNTs. This work brings insight into the role of supporting materials in reducing the loading of metal catalyst towards low-cost ORR in alkaline media

  2. Density functional theory and molecular dynamic studies of hydrogen interaction with plasma-facing graphite surfaces and the impact of boron doping

    International Nuclear Information System (INIS)

    The main drawback of carbon is its strong chemical reactivity to hydrogen isotopes (H/D/T), which leads to chemical erosion/redeposition mechanisms in carbon-lined fusion devices. Computer modeling of tritium retention in carbon requires reflection probability for atomic and molecular species and energy distribution for reflected molecules. In this paper we present first-principle density functional theory (DFT) potential energy surfaces (PES) and molecular dynamic (MD) results concerning the adsorption, diffusion and recombination of atomic hydrogen on the basal terraces and edges of terraces of graphite and on boron-doped graphite. We have shown the important coherence and complementarities between PES and dynamic calculation to model H graphite interaction. Our results are in good agreement with experiment and provide new insights into the mechanism of retention, diffusion and recombination of H on graphite layers. The impact of impurities and defects has also been investigated. The general effect is to increase graphite reactivity toward H. These effects have been quantified and mechanisms (or the way they are modified) have been proposed. (A.C.)

  3. Thermodynamic analysis on synthesis process of diamond

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based upon the thermodynamic analysis of the nucleation of diamond crystal, the effects of synthesis temperature and pressure on the nucleation of diamond crystal, diamond growth and output of diamond crystal, particle size and strength were discussed. The results show that the excess pressure has an important effect on the critical radius of nucleation and thermodynamic barrier in the formation of a critical nucleus. Considering the excess pressure, the expression of diamond nucleation rate was obtained.

  4. 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.

  5. 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

  6. 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.

  7. Wavelet-based fast time-resolved magnetic sensing with electronic spins in diamond

    Science.gov (United States)

    Xu, Nanyang; Jiang, Fengjian; Tian, Yu; Ye, Jianfeng; Shi, Fazhan; Lv, Haijiang; Wang, Ya; Wrachtrup, Jörg; Du, Jiangfeng

    2016-04-01

    Time-resolved magnetic sensing is of great importance from fundamental studies to applications in physical and biological sciences. Recently, the nitrogen-vacancy defect center in diamond has been developed as a promising sensor of magnetic fields under ambient conditions. However, methods to reconstruct time-resolved magnetic fields with high sensitivity are not yet fully developed. Here, we propose and demonstrate a sensing method based on spin echo and Haar wavelet transformation. Our method is exponentially faster in reconstructing time-resolved magnetic fields with comparable sensitivity than existing methods. It is also easier to implement in experiments. Furthermore, the wavelet's unique features enable our method to extract information from the whole signal with only part of the measuring sequences. We then explore this feature for a fast detection of simulated nerve impulses. These results will be useful to time-resolved magnetic sensing with quantum probes at nanoscale.

  8. Competitiveness Analysis of Processing Industry Cluster of Livestock Products in Inner Mongolia Based on "Diamond Model"

    Institute of Scientific and Technical Information of China (English)

    YANG Xing-long; REN Ya-tong

    2012-01-01

    Using Michael Porter’s "diamond model", based on regional development characteristics, we conduct analysis of the competitiveness of processing industry cluster of livestock products in Inner Mongolia from six aspects (the factor conditions, demand conditions, corporate strategy, structure and competition, related and supporting industries, government and opportunities). And we put forward the following rational recommendations for improving the competitiveness of processing industry cluster of livestock products in Inner Mongolia: (i) The government should increase capital input, focus on supporting processing industry of livestock products, and give play to the guidance and aggregation effect of financial funds; (ii) In terms of enterprises, it is necessary to vigorously develop leading enterprises, to give full play to the cluster effect of the leading enterprises.

  9. Strongly correlated impurity band superconductivity in diamond: X-ray spectroscopic evidence

    Directory of Open Access Journals (Sweden)

    G. Baskaran

    2006-01-01

    Full Text Available In a recent X-ray absorption study in boron doped diamond, Nakamura et al. have seen a well isolated narrow boron impurity band in non-superconducting samples and an additional narrow band at the chemical potential in a superconducting sample. We interpret the beautiful spectra as evidence for upper Hubbard band of a Mott insulating impurity band and an additional metallic 'mid-gap band' of a conducting 'self-doped' Mott insulator. This supports the basic framework of a recent theory of the present author of strongly correlated impurity band superconductivity (impurity band resonating valence bond, IBRVB theory in a template of a wide-gap insulator, with no direct involvement of valence band states.

  10. Diamond electrodes for trace alpha pollutant sequestration via covalent grafting of nitrilotriacetic acid (NTA) ligand

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • A straightforward method for NTA ligand covalent immobilization on BBD electrode was described. • This work also demonstrated for the first time that the BDD electrode could easily be functionalized using electrochemical oxidation of aromatic aminated compounds. • NTA functionalized surfaces exhibit a reversible actinide trace sequestration. - Abstract: We describe a very simple and efficient route to functionalize boron-doped-diamond (BDD) electrodes with a chelating nitrilotriacetic acid (NTA) ligand. The BDD electrode surface was first functionalized with a carboxylic acid group via electrochemical grafting of 4-aminophenylcarboxylic acid in aqueous solution and subsequently linked to NTA ligand via a coupling reaction with amine terminated NTA ligand in PBS solution (pH 7.5). Modified BBD surfaces were characterized using X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The present study has demonstrated that NTA functionalized BDD surfaces can successfully be used for reversible 241Am sequestration in aqueous solution

  11. In situ detection of dopamine using nitrogen incorporated diamond nanowire electrode

    Science.gov (United States)

    Shalini, Jayakumar; Sankaran, Kamatchi Jothiramalingam; Dong, Chung-Li; Lee, Chi-Young; Tai, Nyan-Hwa; Lin, I.-Nan

    2013-01-01

    Significant difference was observed for the simultaneous detection of dopamine (DA), ascorbic acid (AA), and uric acid (UA) mixture using nitrogen incorporated diamond nanowire (DNW) film electrodes grown by microwave plasma enhanced chemical vapor deposition. For the simultaneous sensing of ternary mixtures of DA, AA, and UA, well-separated voltammetric peaks are obtained using DNW film electrodes in differential pulse voltammetry (DPV) measurements. Remarkable signals in cyclic voltammetry responses to DA, AA and UA (three well defined voltammetric peaks at potentials around 235, 30, 367 mV for DA, AA and UA respectively) and prominent enhancement of the voltammetric sensitivity are observed at the DNW electrodes. In comparison to the DPV results of graphite, glassy carbon and boron doped diamond electrodes, the high electrochemical potential difference is achieved via the use of the DNW film electrodes which is essential for distinguishing the aforementioned analytes. The enhancement in EC properties is accounted for by increase in sp2 content, new C-N bonds at the diamond grains, and increase in the electrical conductivity at the grain boundary, as revealed by X-ray photoelectron spectroscopy and near edge X-ray absorption fine structure measurements. Consequently, the DNW film electrodes provide a clear and efficient way for the selective detection of DA in the presence of AA and UA.Significant difference was observed for the simultaneous detection of dopamine (DA), ascorbic acid (AA), and uric acid (UA) mixture using nitrogen incorporated diamond nanowire (DNW) film electrodes grown by microwave plasma enhanced chemical vapor deposition. For the simultaneous sensing of ternary mixtures of DA, AA, and UA, well-separated voltammetric peaks are obtained using DNW film electrodes in differential pulse voltammetry (DPV) measurements. Remarkable signals in cyclic voltammetry responses to DA, AA and UA (three well defined voltammetric peaks at potentials around 235

  12. High quality factor nanocrystalline diamond micromechanical resonators limited by thermoelastic damping

    International Nuclear Information System (INIS)

    We demonstrate high quality factor thin-film nanocrystalline diamond micromechanical resonators with quality factors limited by thermoelastic damping. Cantilevers, single-anchored and double-anchored double-ended tuning forks, were fabricated from 2.5 μm thick in-situ boron doped nanocrystalline diamond films deposited using hot filament chemical vapor deposition. Thermal conductivity measured by time-domain thermoreflectance resulted in 24 ± 3 W m−1 K−1 for heat transport through the thickness of the diamond film. The resonant frequencies of the fabricated resonators were 46 kHz–8 MHz and showed a maximum measured Q ≈ 86 000 at fn = 46.849 kHz. The measured Q-factors are shown to be in good agreement with the limit imposed by thermoelastic dissipation calculated using the measured thermal conductivity. The mechanical properties extracted from resonant frequency measurements indicate a Young's elastic modulus of ≈788 GPa, close to that of microcrystalline diamond

  13. Films and Disperse Materials Based on Diamond-Like and Related Structures

    Science.gov (United States)

    Gun'ko, V. M.; Mikhalovsky, S. V.; Mikhalovska, L. I.; Tomlins, P.; Field, S.; Teer, D. G.; Fitzgerald, S.; Fucassi, F.; Bogatyrev, V. M.; Semikina, T. V.; Turanska, S. P.; Borysenko, M. V.; Turov, V. V.; Gorbyk, P. P.

    Structural, adsorption, mechanical and other properties of diamond-like carbon (DLC) films, ultradisperse diamonds and porous diamond compacts were studied in comparison with Ti, TiO X , TiN X , TiC, Zr, ZrO X , ZrN X , ZrC, SiO2, graphite-like carbon film and graphitised carbon black. Control of the properties of DLC materials by doping or surface modification, high mechanical characteristics and tribological behaviour, chemical passivity, biocompatibility and nontoxicity allow the use of these materials in industry and medicine.

  14. REVIEW ARTICLE: Diamond for bio-sensor applications

    Science.gov (United States)

    Nebel, Christoph E.; Rezek, Bohuslav; Shin, Dongchan; Uetsuka, Hiroshi; Yang, Nianjun

    2007-10-01

    A summary of photo- and electrochemical surface modifications applied on single-crystalline chemical vapour deposition (CVD) diamond films is given. The covalently bonded formation of amine- and phenyl-linker molecule layers is characterized using x-ray photoelectron spectroscopy, atomic force microscopy (AFM), cyclic voltammetry and field-effect transistor characterization experiments. Amine- and phenyl-layers are very different with respect to formation, growth, thickness and molecule arrangement. We detect a single-molecular layer of amine-linker molecules on diamond with a density of about 1014 cm-2 (10% of carbon bonds). Amine molecules are bonded only on initially H-terminated surface areas to carbon. In the case of electrochemical deposition of phenyl-layers, multi-layer formation is detected due to three-dimensional (3D) growths. This gives rise to the formation of typically 25 Å thick layers. The electrochemical grafting of boron-doped diamond works on H-terminated and oxidized surfaces. After reacting such films with hetero-bifunctional crosslinker molecules, thiol-modified ss-DNA markers are bonded to the organic system. Application of fluorescence and AFM on hybridized DNA films shows dense arrangements with densities of up to 1013 cm-2. The DNA is tilted by an angle of about 35° with respect to the diamond surface. Shortening the bonding time of thiol-modified ss-DNA to 10 min causes a decrease of DNA density to about 1012 cm-2. Application of AFM scratching experiments shows threshold removal forces of around 75 nN for DNA bonded on phenyl-linker molecules and of about 45 nN for DNA bonded to amine-linker molecules. DNA sensor applications using Fe(CN6)3-/4- mediator redox molecules, impedance spectroscopy and DNA-field effect transistor devices performances are introduced and discussed.

  15. Role of swift heavy ions irradiation on the emission of boron doped ZnO thin films for near white light application

    International Nuclear Information System (INIS)

    Highlights: • ZnO:B thin film irradiated by 80 MeV Br6+ ions. • Compressive to tensile stress was observed with increase in fluences. • Oxygen related defect is decreased after irradiation. • Near white light emission was achieved in the ZnO:B. • The colour of the emitted light can be tuned by SHI. - Abstract: Boron doped ZnO (ZnO:B) thin films on silicon substrates were synthesized with the sol–gel method using the spin coating technique. The films were irradiated by 80 MeV Br+6 ions at various ion fluences. The X-ray diffraction results indicate that ZnO:B crystallized in the normal hexagonal wurtzite structure of ZnO. X-ray photoelectron spectroscopy data indicated that the O1s peak consist of three components designated as O1 (coming from ZnO), O2 (coming from defects) and O3 (coming from adsorbed species). Defect level emission (DLE) was obtained in the luminescence spectra of the pristine ZnO:B sample while the strong UV emission was observed for the ion irradiated films. The intensity of the DLE emission decreased after irradiation while the band to band emission increased after ion irradiation. A direct correlation between the amount of defects (O2 peak of XPS) and the DLE was observed. The emission of the ZnO:B is exponentially correlated with the swift heavy ion induced stress and the amount of defects. These ZnO:B thin films may be used for near white light emission applications

  16. 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.

  17. Metal ion analysis in contaminated water samples using anodic stripping voltammetry and a nanocrystalline diamond thin-film electrode

    International Nuclear Information System (INIS)

    Boron-doped nanocrystalline diamond thin-film electrodes were employed for the detection and quantification of Ag (I), Cu (II), Pb (II), Cd (II), and Zn (II) in several contaminated water samples using anodic stripping voltammetric (ASV). Diamond is an alternate electrode that possesses many of the same attributes as Hg and, therefore, appears to be a viable material for this electroanalytical measurement. The nanocrystalline form has been found to perform slightly better than the more conventional microcrystalline form of diamond in this application. Differential pulse voltammetry (DPASV) was used to detect these metal ions in lake water, well water, tap water, wastewater treatment sludge, and soil. The electrochemical results were compared with data from inductively coupled plasma mass spectrometric (ICP-MS) and or atomic absorption spectrometric (AAS) measurements of the same samples. Diamond is shown to function well in this electroanalytical application, providing a wide linear dynamic range, a low limit of quantitation, excellent response precision, and good response accuracy. For the analysis of Pb (II), bare diamond provided a response nearly identical to that obtained with a Hg-coated glassy carbon electrode

  18. Free standing diamond-like carbon thin films by PLD for laser based electrons/protons acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Thema, F.T.; Beukes, P.; Ngom, B.D. [UNESCO Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West, 7129, PO Box722, Western Cape Province (South Africa); Manikandan, E., E-mail: mani@tlabs.ac.za [UNESCO Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West, 7129, PO Box722, Western Cape Province (South Africa); Central Research Laboratory, Sree Balaji Medical College & Hospital (SBMCH), Chrompet, Bharath University, Chennai, 600044 (India); Maaza, M., E-mail: maaza@tlabs.ac.za [UNESCO Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West, 7129, PO Box722, Western Cape Province (South Africa)

    2015-11-05

    This study we reports for the first time on the synthesis and optical characteristics of free standing diamond-like carbon (DLC) deposited by pulsed laser deposition (PLD) onto graphene buffer layers for ultrahigh intensity laser based electron/proton acceleration applications. The fingerprint techniques of micro-Raman, UV–VIS–NIR and the IR spectroscopic investigations indicate that the suitability of such free standing DLC thin-films within the laser window and long wave infrared (LWIR) spectral range and hence their appropriateness for the targeted applications. - Highlights: • We report for the first time synthesis of free standing diamond-like carbon. • Pulsed laser deposition onto graphene buffer layers. • Fingerprint techniques of micro-Raman, UV–VIS–NIR and the IR spectroscopic investigations. • Ultrahigh intensity laser based electron/proton acceleration applications. • This material's suitable for the laser window and long wave infrared (LWIR) spectral range.

  19. Free standing diamond-like carbon thin films by PLD for laser based electrons/protons acceleration

    International Nuclear Information System (INIS)

    This study we reports for the first time on the synthesis and optical characteristics of free standing diamond-like carbon (DLC) deposited by pulsed laser deposition (PLD) onto graphene buffer layers for ultrahigh intensity laser based electron/proton acceleration applications. The fingerprint techniques of micro-Raman, UV–VIS–NIR and the IR spectroscopic investigations indicate that the suitability of such free standing DLC thin-films within the laser window and long wave infrared (LWIR) spectral range and hence their appropriateness for the targeted applications. - Highlights: • We report for the first time synthesis of free standing diamond-like carbon. • Pulsed laser deposition onto graphene buffer layers. • Fingerprint techniques of micro-Raman, UV–VIS–NIR and the IR spectroscopic investigations. • Ultrahigh intensity laser based electron/proton acceleration applications. • This material's suitable for the laser window and long wave infrared (LWIR) spectral range

  20. 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.

  1. Most diamonds were created equal

    Science.gov (United States)

    Jablon, Brooke Matat; Navon, Oded

    2016-06-01

    Diamonds crystallize deep in the mantle (>150 km), leaving their carbon sources and the mechanism of their crystallization debatable. They can form from elemental carbon, by oxidation of reduced species (e.g. methane) or reduction of oxidized ones (e.g. carbonate-bearing minerals or melts), in response to decreasing carbon solubility in melts or fluids or due to changes in pH. The mechanism of formation is clear for fibrous diamonds that grew from the carbonate-bearing fluids trapped in their microinclusions. However, these diamonds look different and, based on their lower level of nitrogen aggregation, are much younger than most monocrystalline (MC) diamonds. In the first systematic search for microinclusions in MC diamonds we examined twinned crystals (macles), assuming that during their growth, microinclusions were trapped along the twinning plane. Visible mineral inclusions (>10 μm) and nitrogen aggregation levels in these clear macles are similar to other MC diamonds. We found 32 microinclusions along the twinning planes in eight out of 30 diamonds. Eight inclusions are orthopyroxene; four contain >50% K2O (probably as K2(Mg, Ca)(CO3)2); but the major element compositions of the remaining 20 are similar to those of carbonate-bearing high-density fluids (HDFs) found in fibrous diamonds. We conclude that the source of carbon for these macles and for most diamonds is carbonate-bearing HDFs similar to those found here and in fibrous diamonds. Combined with the old ages of MC diamonds (up to 3.5 Ga), our new findings suggest that carbonates have been introduced into the reduced lithospheric mantle since the Archaean and that the mechanism of diamond formation is the same for most diamonds.

  2. A procedure for diamond turning KDP crystals

    Energy Technology Data Exchange (ETDEWEB)

    Montesanti, R.C.; Thompson, S.L.

    1995-07-07

    A procedure and the equipment necessary for single-point diamond flycutting (loosely referred to as diamond turning) potassium di-hydrogen phosphate (KDP) crystals are described. It is based on current KDP diamond turning activities at the Lawrence Livermore National Laboratory (LLNL), drawing upon knowledge from the Nova crystal finishing development during the 1980`s and incorporating refinements from our efforts during 1995. In addition to describing a step-by-step process for diamond turning KDP, specific discussions are included on the necessary diamond tool geometry and edge sharpness, cutting fluid, and crystal preparation, handling, cleaning, and inspection. The authors presuppose that the reader is already familiar with diamond turning practices.

  3. Low temperature synthesis of diamond-based nano-carbon composite materials with high electron field emission properties

    International Nuclear Information System (INIS)

    A diamond-based nano-carbon composite (d/NCC) material, which contains needle-like diamond grains encased with the nano-graphite layers, was synthesized at low substrate temperature via a bias enhanced growth process using CH4/N2 plasma. Such a unique granular structure renders the d/NCC material very conductive (σ = 714.8 S/cm), along with superior electron field emission (EFE) properties (E0 = 4.06 V/μm and Je = 3.18 mA/cm2) and long lifetime (τ = 842 min at 2.41 mA/cm2). Moreover, the electrical conductivity and EFE behavior of d/NCC material can be tuned in a wide range that is especially useful for different kind of applications

  4. Low temperature synthesis of diamond-based nano-carbon composite materials with high electron field emission properties

    Energy Technology Data Exchange (ETDEWEB)

    Saravanan, A.; Huang, B. R. [Graduate Institute of Electro-Optical Engineering and Department of Electronic Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Yeh, C. J.; Leou, K. C. [Department of Engineering and System Science, National Tsing Hua University, Hsinchu 300, Taiwan (China); Lin, I. N., E-mail: inanlin@mail.tku.edu.tw [Department of Physics, Tamkang University, Tamsui 251, Taiwan (China)

    2015-06-08

    A diamond-based nano-carbon composite (d/NCC) material, which contains needle-like diamond grains encased with the nano-graphite layers, was synthesized at low substrate temperature via a bias enhanced growth process using CH{sub 4}/N{sub 2} plasma. Such a unique granular structure renders the d/NCC material very conductive (σ = 714.8 S/cm), along with superior electron field emission (EFE) properties (E{sub 0} = 4.06 V/μm and J{sub e} = 3.18 mA/cm{sup 2}) and long lifetime (τ = 842 min at 2.41 mA/cm{sup 2}). Moreover, the electrical conductivity and EFE behavior of d/NCC material can be tuned in a wide range that is especially useful for different kind of applications.

  5. Raman barometry of diamond formation

    Science.gov (United States)

    Izraeli, E. S.; Harris, J. W.; Navon, O.

    1999-11-01

    Pressures and temperatures of the diamond source region are commonly estimated using chemical equilibria between coexisting mineral inclusions. Here we present another type of geobarometer, based on determination of the internal pressure in olivine inclusions and the stresses in the surrounding diamond. Using Raman spectroscopy, pressures of 0.13 to 0.65 GPa were measured inside olivine inclusions in three diamonds from the Udachnaya mine in Siberia. Stresses in the diamond surrounding the inclusions indicated similar pressures (0.11-0.41 GPa). Nitrogen concentration and aggregation state in two of the diamonds yielded mantle residence temperatures of ˜1200°C. Using this temperature and the bulk moduli and thermal expansion of olivine and diamond, we calculated source pressures of 4.4-5.2 GPa. We also derived a linear approximation for the general dependence of the source pressure ( P0, GPa) on source temperature ( T0, °C) and the measured internal pressure in the inclusion ( Pi): P0=(3.259×10 -4Pi+3.285×10 -3) T0+0.9246 Pi+0.319. Raman barometry may be applied to other inclusions in diamonds or other inclusion-host systems. If combined with IR determination of the mantle residence temperature of the diamond, it allows estimation of the pressure at the source based on a non-destructive examination of a single diamond containing a single inclusion.

  6. Mechanically induced degradation of diamond

    International Nuclear Information System (INIS)

    This thesis deals with the wear of diamond occurring during frictional sliding contact between diamonds. In the introduction, a literature survey on friction, wear and polishing behaviour of diamond, with some emphasis on the anisotropy, is presented and earlier work is discussed. A review of the existing theories is given, a new hypothesis is proposed and key-experiments for verification are identified. Electron microscopical techniques such as High Resolution Electron Microscopy (HREM) imaging and Electron Energy Loss Spectroscopy are described as they were employed to study the nature of the surface damage and the debris which is formed during sliding contact. The results of these experiments indicate that a transformation from diamond to graphite may take place during shearing contact of diamonds. A microscopic model, which is a further refinement of the hypothesis, is developed and its prediction on the orientation dependency for shear-induced graphitisation is found to correspond to the observed anisotropy in the friction, wear and polishing behaviour of diamond. The model, based on c transformation of sp3-coordinated carbon into sp2-coordinated carbon due to excessive distortions of the diamond bonds, is used to describe phenomena occurring during macroscopic experiments. A HREM study of controlled ion beam bombarded Chemical Vapour Deposited (CVD) Diamond is presented to demonstrate the broader applicability of the model. It is found that during the ion bombardment a mechanically induced graphitisation, as opposed to a thermally activated transformation, may occur locally on collision with the CVD diamond. Two types of diamond-graphite interfaces were observed: (111) planes of diamond parallel to the a-b planes of graphite and (111) planes of diamond, smoothly within the plane, connected to a-b planes of graphite. The thesis concludes with a summary of the results, conclusions and recommendations for further work. (author)

  7. 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)

  8. Super-mercuryphobic and hydrophobic diamond surfaces with hierarchical structures: Vanishment of the contact angle hysteresis with mercury

    International Nuclear Information System (INIS)

    Increased roughness is known to enhance the natural wetting properties of surfaces, making them either more hydrophobic or more hydrophilic. In this work we study the wetting properties of water and mercury drops in contact with boron doped diamond films with progressively increased surface roughnesses. We show how thermal oxidation of a microcrystalline film creates pyramids decorated with sub-micron protrusions that turn its naturally mercuryphobic surface into super-mercuryphobic. With this liquid, we observe the vanishment of the contact angle hysteresis that is expected for rough surfaces as the contact angle approaches 180, making small drops of mercury roll along out of the surface at an apparent zero tilt-angle. In contrast, the incorporation of nano-globules on the oxidized surface through a silanization process is necessary to increase the hydrophobic properties of the film for which the contact angle with water reaches 138°. The wetting states that dominate in each case are discussed.

  9. Direct optical interfacing of CVD diamond for deported NV-based sensing experiments

    CERN Document Server

    Mayer, Ludovic

    2016-01-01

    Nitrogen-vacancy (NV) defect in diamond is a very promising tool for numerous sensing applications like magnetometry or thermometry. In this paper, we demonstrate a compact and convenient device for magnetic field imaging where a commercial single mode photonic crystal fibre is directly coupled to a commercial CVD ppm diamond. We managed to excite and detect efficiently the luminescence from an ensemble of NV centres and also to perform Electron Spin Resonance (ESR) experiments where the NV hyperfine structure is perfectly resolved under continuous excitation and measurement.

  10. Calibration of CVD-diamond based dosimeter in high-power electron and x-ray radiation fields

    International Nuclear Information System (INIS)

    Results of a study of dosimetry characteristics of a prototype of the detector based on a polycrystalline diamond film (CVD-diamond) produced in NSC KIPT are summarized. The techniques of the detector calibration against the electron and X-ray radiation dose rate are developed. The conditions of calibration were studied by means of computer simulation. For determination of detector sensitivity to electron radiation, it was placed inside of a standard polystyrene phantom. An additional filter of electrons was used at measurement in the X-ray field. Every time detector irradiation was carried out together with the Harwell Red Perpex 4034 dosimeters, which registrations provided the calibration data. The measurements, executed at the LU-10, EPOS and LU-40 linacs of NSC KIPT, have demonstrated, that the values of detector sensitivity against each type of radiation are close and conform to ones obtained earlier for the low-intensity radiation fields. Considering significant radiation durability of the CVD-diamond, it enables its application in technological dosimetry.

  11. A novel diamond-based beam position monitoring system for the High Radiation to Materials facility at CERN SPS

    CERN Document Server

    AUTHOR|(CDS)2092886; Höglund, Carina

    The High Radiation to Materials facility employs a high intensity pulsed beam imposing several challenges on the beam position monitors. Diamond has been shown to be a resilient material with its radiation hardness and mechanical strength, while it is also simple due to its wide bandgap removing the need for doping. A new type of diamond based beam position monitor has been constructed, which includes a hole in the center of the diamond where the majority of the beam is intended to pass through. This increases the longevity of the detectors as well as allowing them to be used for high intensity beams. The purpose of this thesis is to evaluate the performance of the detectors in the High Radiation to Materials facility for various beam parameters, involving differences in position, size, bunch intensity and bunch number. A prestudy consisting of calibration of the detectors using single incident particles is also presented. The detectors are shown to work as intended after a recalibration of the algorithm, alb...

  12. CONTROL OF METAL SURFACES MACHINED IN ACCORDANCE WITH THE DIAMOND NANOMACHINING TECHNOLOGY BASED ON THE ELECTRON WORK FUNCTION

    Directory of Open Access Journals (Sweden)

    G. V. Sharonov

    2015-01-01

    Full Text Available Dimensional machining technology is based on the use of integrated geometric parameters of machined surfaces. Technological impact of a pick results in oxidation processes and changes in physic-chemical parameters of surface. Control of only geometric parameters is insufficient to describe characteristics of machining and formation of ultra-smooth surfaces. The electron work function is therefore used. The aim of the work was to study electrophysical states of optic surfaces of non-ferrous metals and alloys in relation to geometric and physic-chemical parameters according to the distribution of the electron work function over the surface. We conducted the study on experimental metal samples made of copper and aluminum alloy, machined in accordance with the diamond nanomachining technology. The diamond nanomachining technology would be capable of ensuring the roughness of non-ferrous metals and alloys machined at the level of Ra ≤ 0,005 µm. Modernized Kelvin probe was used as the registration technique of the changes of the electron work function over the surface. Dependence between the electron work function value, as well as its alteration and the physicchemical and geometric parameters of a surface has been determined. It has been shown that the diamond nanomachining technology makes it possible to obtain electro-physically uniform optical surfaces on copper and aluminum alloy with the minimal range of the distribution of the electric potential over the surface. 

  13. A novel electroless method to prepare a platinum electrocatalyst on diamond for fuel cell applications

    Science.gov (United States)

    Lyu, Xiao; Hu, Jingping; Foord, John S.; Wang, Qiang

    2013-11-01

    A novel electroless deposition method was demonstrated to prepare a platinum electrocatalyst on boron doped diamond (BDD) substrates without the need for pre-activation. This green method addresses the uniformity and particle size issues associated with electrodeposition and circumvents the pre-activation procedure which is necessary for conventional electroless deposition. The inert BDD substrate formed a galvanic couple with an iron wire, to overcome the activation barrier associated with conventional electroless deposition on diamond, leading to the formation of Pt nanoparticles on the electrode surface in a galvanic process coupled to a chemical process. When sodium hypophosphite was employed as the reducing agent to drive the electroless reaction Pt deposits which were contaminated with iron and phosphorus resulted. In contrast, the reducing agent ascorbic acid gave rise to high purity Pt nanoparticles. Optimal deposition conditions with respect to bath temperature, pH value and stabilizing additives are identified. Using this approach, high purity and uniformly distributed platinum nanoparticles are obtained on the diamond electrode surface, which demonstrate a high electrochemical activity towards methanol oxidation.

  14. MEMS silicon-based micro-evaporator with diamond-shaped fins

    NARCIS (Netherlands)

    Mihailovic, M.; Rops, C.; Creemer, J.F.; Sarro, P.M.

    2010-01-01

    A new design of micro-evaporators, with 45 channels (100 μm deep) and diamond-shaped fins (40μm wide, 160μm long, 20μm separation), is fabricated by anodic bonding of silicon and glass wafers, in a five masks process. This new design improves stability of the working conditions, and has a localized

  15. Integrated diamond networks for quantum nanophotonics

    CERN Document Server

    Hausmann, Birgit J M; Quan, Qimin; Maletinsky, Patrick; McCutcheon, Murray; Choy, Jennifer T; Babinec, Tom M; Kubanek, Alexander; Yacoby, Amir; Lukin, Mikhail D; Loncar, Marko

    2011-01-01

    Diamond is a unique material with exceptional physical and chemical properties that offers potential for the realization of high-performance devices with novel functionalities. For example diamond's high refractive index, transparency over wide wavelength range, and large Raman gain are of interest for the implementation of novel photonic devices. Recently, atom-like impurities in diamond emerged as an exceptional system for quantum information processing, quantum sensing and quantum networks. For these and other applications, it is essential to develop an integrated nanophotonic platform based on diamond. Here, we report on the realization of such an integrated diamond photonic platform, diamond on insulator (DOI), consisting of a thin single crystal diamond film on top of an insulating silicon dioxide/silicon substrate. Using this approach, we demonstrate diamond ring resonators that operate in a wide wavelength range, including the visible (630nm) and near-infrared (1,550nm). Finally, we demonstrate an int...

  16. Electrochemical diamond sensors for TNT detection in water

    International Nuclear Information System (INIS)

    An electrochemically stabilized boron doped diamond electrode prepared by chemical vapour deposition (CVD) is used for electrochemical TNT sensing in aqueous solutions. Square wave voltammograms (SWVs) exhibit three highly resolved peaks at -0.47, -0.62 and -0.76 V vs. Ag-AgCl reference electrode, respectively. The current vs. TNT concentration plot shows a linear relationship with a same slope for the two first TNT peaks at μg L-1 and mg L-1 concentration ranges. Detection and quantification limits of 10 and 25 μg L-1, respectively, were obtained without any preconcentration step. Relative standard deviation (RSD) of less than 1% measured over 10 runs has been found for the -0.47 V peak current showing the very high stability of the electrode without any significant fouling effect. An interference study with nitro aromatic compounds of the same family (nitro toluene and dinitrotoluene) has shown that the -0.47 V reduction peak enables TNT discrimination. Measurement of TNT in a natural medium (sea water without any purification step except filtering) has been also investigated.

  17. Diamond for Actinide Traces Detection and Spectrometry in Liquids

    International Nuclear Information System (INIS)

    We describe here a new approach for the detection and identification of actinides (Am, Pu, Cm etc) at very low activity levels in aqueous solution. The measurement consists at first in the electro-precipitation of the actinides ions as insoluble hydroxides directly onto a boron doped nanocrystalline diamond (BNCD) electrode deposited on an α-particle detector (Si or Si-PIN diode), followed by α-particles detection using front-end nuclear electronics. After α-particles counting, spectrometry, the detector can be easily decontaminated using anodization in aqueous solution to be able to be reused at once. The detection limit of the described prototype system can be estimated as low as a few mBq=L (for one day counting) to several mBq=L for 5 h counting and currently achieved energy resolution amounts to ΔEFW HM/Eα = 2.3% for pulse height spectra of 5.486 MeV α-particles emitted by 241Am, measured directly in water. (authors)

  18. Electrochemical diamond sensors for TNT detection in water

    Energy Technology Data Exchange (ETDEWEB)

    Sanoit, J. de [CEA-LIST-DETECS, Laboratoire Capteur Diamant, CEA-Saclay, Gif-sur Yvette, F-91191 (France)], E-mail: jacques.desanoit@cea.fr; Vanhove, Emilie [CEA-LIST-DETECS, Laboratoire Capteur Diamant, CEA-Saclay, Gif-sur Yvette, F-91191 (France); Mailley, Pascal [INAC, SPrAM, CREAB (CEA-Grenoble), F-38021 (France); Bergonzo, Philippe [CEA-LIST-DETECS, Laboratoire Capteur Diamant, CEA-Saclay, Gif-sur Yvette, F-91191 (France)

    2009-10-01

    An electrochemically stabilized boron doped diamond electrode prepared by chemical vapour deposition (CVD) is used for electrochemical TNT sensing in aqueous solutions. Square wave voltammograms (SWVs) exhibit three highly resolved peaks at -0.47, -0.62 and -0.76 V vs. Ag-AgCl reference electrode, respectively. The current vs. TNT concentration plot shows a linear relationship with a same slope for the two first TNT peaks at {mu}g L{sup -1} and mg L{sup -1} concentration ranges. Detection and quantification limits of 10 and 25 {mu}g L{sup -1}, respectively, were obtained without any preconcentration step. Relative standard deviation (RSD) of less than 1% measured over 10 runs has been found for the -0.47 V peak current showing the very high stability of the electrode without any significant fouling effect. An interference study with nitro aromatic compounds of the same family (nitro toluene and dinitrotoluene) has shown that the -0.47 V reduction peak enables TNT discrimination. Measurement of TNT in a natural medium (sea water without any purification step except filtering) has been also investigated.

  19. Diamond Sensors for Energy Frontier Experiments

    CERN Document Server

    Schnetzer, Steve

    2014-01-01

    We discuss the use of diamond sensors in high-energy, high-i ntensity collider experiments. Re- sults from diamond sensor based beam conditions monitors in the ATLAS and CMS experiments at the CERN Large Hadron Collider (LHC) are presented and pla ns for diamond based luminosity monitors for the upcoming LHC run are described. We describe recent measurements on single crystal diamond sensors that indicate a polarization effec t that causes a reduction of charge col- lection efficiency as a function of particle flux. We conclude by describing new developments on the promising technology of 3D diamond sensors.

  20. 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