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Sample records for boron doped diamond

  1. Ultratough single crystal boron-doped diamond

    Science.gov (United States)

    Hemley, Russell J [Carnegie Inst. for Science, Washington, DC ; Mao, Ho-Kwang [Carnegie Inst. for Science, Washington, DC ; Yan, Chih-Shiue [Carnegie Inst. for Science, Washington, DC ; Liang, Qi [Carnegie Inst. for Science, Washington, DC

    2015-05-05

    The invention relates to a single crystal boron doped CVD diamond that has a toughness of at least about 22 MPa m.sup.1/2. The invention further relates to a method of manufacturing single crystal boron doped CVD diamond. The growth rate of the diamond can be from about 20-100 .mu.m/h.

  2. Steam activation of boron doped diamond electrodes

    International Nuclear Information System (INIS)

    Ohashi, Tatsuya; Zhang Junfeng; Takasu, Yoshio; Sugimoto, Wataru

    2011-01-01

    Highlights: → Steam activation of boron doped diamond (BDD) electrodes. → Steam activated BDD has a porous columnar texture. → Steam activated BDD has a wide potential window. - Abstract: Boron doped diamond (BDD) electrodes were activated in steam at various temperatures, resulting in high quality BDD electrodes with a porous microstructure. Distinct columnar structures were observed by scanning electron microscopy. The electrochemically active surface area of the steam-activated BDD was up to 20 times larger than the pristine BDD electrode owing to the porous texture. In addition, a widening of the potential window was observed after steam activation, suggesting that the quality of BDD was enhanced due to oxidative removal of graphitic impurities during the activation process.

  3. Transport properties of polycrystalline boron doped diamond

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, J.R. de [Instituto Nacional de Pesquisas Espaciais, INPE/LAS, S.J. Campos, SP 12227-010 (Brazil); Berengue, O.M. [Universidade Estadual Paulista, UNESP Departamento de Física, Guaratinguetá 12.516-410 (Brazil); Moro, J. [Instituto Federal de Educação, Ciência e Tecnologia de São Paulo, Bragança Paulista 12929-600 (Brazil); Ferreira, N.G. [Instituto Nacional de Pesquisas Espaciais, INPE/LAS, S.J. Campos, SP 12227-010 (Brazil); Chiquito, A.J. [Universidade Federal de São Carlos, Departamento de Física, São Carlos 13565-905 (Brazil); Baldan, M.R., E-mail: baldan@las.inpe.br [Instituto Nacional de Pesquisas Espaciais, INPE/LAS, S.J. Campos, SP 12227-010 (Brazil)

    2014-08-30

    Highlights: • Synthetic boron doped diamond films were grown by hot filament chemical vapor deposition. • We characterized the films by hall effects as a function of temperature and magnetic field. • The resistivity was investigated. • The conduction mechanism was dominated by variable range hopping (VRH). - Abstract: The influence of doping level in the electronic conductivity and resistivity properties of synthetic diamond films grown by hot filament chemical vapor deposition (HFCVD) was investigated. Eight different doping level concentrations varied from 500 to 30,000 ppm were considered. The polycrystalline morphology observed by scanning electron microscopy and Raman spectra was strongly affected by the addition of boron. The electric characterization by Hall effect as a function of temperature and magnetic field showed that at sufficiently low temperatures, electrical conduction is dominated by variable range hopping (VRH) conducting process. The resistivity was also investigated by temperature-dependent transport measurements in order to investigate the conduction mechanism in the doped samples. The samples exhibited the VRH (m = 1/4) mechanism in the temperature range from 77 to 300 K. The interface between metal, and our HFCVD diamond was also investigated for the lower doped samples.

  4. Characterization of boron doped nanocrystalline diamonds

    International Nuclear Information System (INIS)

    Peterlevitz, A C; Manne, G M; Sampaio, M A; Quispe, J C R; Pasquetto, M P; Iannini, R F; Ceragioli, H J; Baranauskas, V

    2008-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, R.; Sasama, Y.; Yamaguchi, T.; Takano, Y. [MANA, National Institute for Materials Science, Tsukuba 305-0047 (Japan); Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8577 (Japan); Fujioka, M. [MANA, National Institute for Materials Science, Tsukuba 305-0047 (Japan); Laboratory of Nano-Structure Physics, Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0020 (Japan); Irifune, T. [Geodynamics Research Center, Ehime University, Matsuyama 790-8577 (Japan); Tanaka, M.; Takeya, H. [MANA, National Institute for Materials Science, Tsukuba 305-0047 (Japan)

    2016-07-15

    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.

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

    OpenAIRE

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

    2013-01-01

    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 streng...

  7. Ferrate(VI synthesis at boron-doped diamond anode

    Directory of Open Access Journals (Sweden)

    Čekerevac Milan

    2013-01-01

    Full Text Available The oxidation of iron compounds from alkaline 10 M KOH electrolytes on a boron doped diamond electrode is examined by cyclic voltammetry between the potentials of hydrogen evolution reaction and oxygen evolution reaction, due to ferrate(VI electrochemical synthesis. It is shown that the anodic current peak that appears in iron free electrolyte at a less positive potential than the potential of oxygen evolution probably coincides with oxidation of hydrogen in >CH2 groups and C-sp2 graphite impurities with formation of >C=O groups at C-sp3 diamond structure. Addition of Fe(III compounds to the electrolyte provoke formation of the anodic wave on cyclic voltammograms in the potential region which correlates with generation of ferrate(VI. It is concluded that the direct electrochemical synthesis of Fe(VI at the boron doped diamond anode is possible because of the less positive potential of ferrate(VIFeO2-4 formation in respect to the potential of oxygen evolution reaction. Presence of ferrate(VI in electrolyte, formed after anodic polarization of boron electrode in 10 M KOH electrolyte saturated with Fe(III at + 0.9 V against Hg|HgO electrode, has been proven by UV-VIS spectrometry.

  8. Structure and superconductivity of isotope-enriched boron-doped diamond

    OpenAIRE

    Evgeny A Ekimov, Vladimir A Sidorov, Andrey V Zoteev, Yury B Lebed, Joe D Thompson and Sergey M Stishov

    2008-01-01

    Superconducting boron-doped diamond samples were synthesized with isotopes of 10B, 11B, 13C and 12C. We claim the presence of a carbon isotope effect on the superconducting transition temperature, which supports the ‘diamond-carbon’-related nature of superconductivity and the importance of the electron–phonon interaction as the mechanism of superconductivity in diamond. Isotope substitution permits us to relate almost all bands in the Raman spectra of heavily boron-doped diamond to the vibrat...

  9. Electron field emission from boron doped microcrystalline diamond

    International Nuclear Information System (INIS)

    Roos, M.; Baranauskas, V.; Fontana, M.; Ceragioli, H.J.; Peterlevitz, A.C.; Mallik, K.; Degasperi, F.T.

    2007-01-01

    Field emission properties of hot filament chemical vapor deposited boron doped polycrystalline diamond have been studied. Doping level (N B ) of different samples has been varied by the B/C concentration in the gas feed during the growth process and doping saturation has been observed for high B/C ratios. Threshold field (E th ) for electron emission as function of B/C concentration has been measured, and the influences of grain boundaries, doping level and surface morphology on field emission properties have been investigated. Carrier transport through conductive grains and local emission properties of surface sites have been figured out to be two independent limiting effects in respect of field emission. Emitter current densities of 500 nA cm -2 were obtained using electric fields less than 8 V/μm

  10. Insight into boron-doped diamond Raman spectra characteristic features

    Czech Academy of Sciences Publication Activity Database

    Mortet, Vincent; Vlčková Živcová, Zuzana; Taylor, Andrew; Frank, Otakar; Hubík, Pavel; Trémouilles, D.; Jomard, F.; Barjon, J.; Kavan, Ladislav

    2017-01-01

    Roč. 115, May (2017), s. 279-284 ISSN 0008-6223 R&D Projects: GA ČR GA13-31783S; GA MŠk 7AMB16FR004 Grant - others:AV ČR(CZ) Fellowship J. E. Purkyně Institutional support: RVO:68378271 ; RVO:61388955 Keywords : diamond * boron doping * Raman spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism; CG - Electrochemistry (UFCH-W) OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.); Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis) (UFCH-W) Impact factor: 6.337, year: 2016

  11. Structure and superconductivity of isotope-enriched boron-doped diamond.

    Science.gov (United States)

    Ekimov, Evgeny A; Sidorov, Vladimir A; Zoteev, Andrey V; Lebed, Julia B; Thompson, Joe D; Stishov, Sergey M

    2008-12-01

    Superconducting boron-doped diamond samples were synthesized with isotopes of 10 B, 11 B, 13 C and 12 C. We claim the presence of a carbon isotope effect on the superconducting transition temperature, which supports the 'diamond-carbon'-related nature of superconductivity and the importance of the electron-phonon interaction as the mechanism of superconductivity in diamond. Isotope substitution permits us to relate almost all bands in the Raman spectra of heavily boron-doped diamond to the vibrations of carbon atoms. The 500 cm -1 Raman band shifts with either carbon or boron isotope substitution and may be associated with vibrations of paired or clustered boron. The absence of a superconducting transition (down to 1.6 K) in diamonds synthesized in the Co-C-B system at 1900 K correlates with the small boron concentration deduced from lattice parameters.

  12. 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.

  13. Front and back side SIMS analysis of boron-doped delta-layer in diamond

    Energy Technology Data Exchange (ETDEWEB)

    Pinault-Thaury, M.-A., E-mail: marie-amandine.pinault-thaury@uvsq.fr [Groupe d’Etude de la Matière Condensée, CNRS, University of Paris Saclay, University of Versailles St Quentin, 45 Avenue des Etats-Unis, 78035 Versailles Cedex (France); Jomard, F. [Groupe d’Etude de la Matière Condensée, CNRS, University of Paris Saclay, University of Versailles St Quentin, 45 Avenue des Etats-Unis, 78035 Versailles Cedex (France); Mer-Calfati, C.; Tranchant, N.; Pomorski, M.; Bergonzo, P.; Arnault, J.-C. [CEA, LIST, Diamond Sensors Laboratory, 91191 Gif-sur-Yvette (France)

    2017-07-15

    Highlights: • Front and back side SIMS analysis of delta-layer boron-doped is a first for diamond. • Combination of front and back side depth profiling improves delta-layer analyses. • Sharp interfaces are evidenced on both sides of the delta-layer boron-doped diamond. • The growth of delta-layer boron doped diamond is now well controlled. - Abstract: Nowadays the availability of very thin diamond layers in the range of nanometers as well as the possibility to characterize such delta-layer structures are required for the field of photonics and spintronics, but also for the development of next generation high power devices involving boron doping. The fabrication of diamond structures with abrupt interfaces such as superlattices and quantum wells has been recently improved. A very accurate characterization is then essential even though the analysis of such structures is arduous and challenging. SIMS analyses are commonly used to obtain depth profiles of dopants. However, below 10 nm in thickness, SIMS induced ion mixing effects which are no longer negligible. Then the raw SIMS profile might differ from the real dopant profile. In this study, we have analyzed a diamond structure containing a thin boron epilayer, especially synthesized to achieve SIMS analysis on both sides and to overcome the effects of ion mixing. We evidence the ion mixing induced by primary ions. Such a structure is a delta diamond layer, comparable to classical boron-doped delta-layer in silicon. Our results show that the growth of boron-doped delta-layer in diamond is now well controlled in terms of thickness and interfaces.

  14. Boron-doped nanocrystalline diamond electrodes for neural interfaces: in vivo biocompatibility evaluation

    Czech Academy of Sciences Publication Activity Database

    Alcaide, M.; Taylor, Andrew; Fjorback, M.; Zachar, V.; Pennisi, C.P.

    2016-01-01

    Roč. 10, Mar (2016), 1-9, č. článku 87. ISSN 1662-453X Institutional support: RVO:68378271 Keywords : nanocrystalline diamond * neuroprosthetic interfaces * neural electrodes * boron-doped diamond * titanium nitride * foreign body reaction Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.566, year: 2016

  15. Factors influencing voltammetric reduction of 5-nitroquinoline at boron-doped diamond electrodes

    Czech Academy of Sciences Publication Activity Database

    Vosáhlová, J.; Zavázalová, J.; Petrák, Václav; Schwarzová-Pecková, K.

    2016-01-01

    Roč. 147, č. 1 (2016), s. 21-29 ISSN 0026-9247 Institutional support: RVO:68378271 Keywords : voltammetry * boron-doped diamond electrode * boron concentration * reduction * electrochemistry Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.282, year: 2016

  16. Boron Doped Nanocrystalline Diamond Films for Biosensing Applications

    Directory of Open Access Journals (Sweden)

    V. Petrák

    2011-01-01

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

  17. The water decomposition reactions on boron-doped diamond electrodes

    Directory of Open Access Journals (Sweden)

    Suffredini Hugo B

    2004-01-01

    Full Text Available The electrochemical processes occurring at both edges of the wide electrochemical window of the boron doped diamond (BDD electrode were studied by polarization curves experiments to evaluate the apparent energy of activation for the rate determining step in each reaction. It was found that the hydrogen evolution reaction occurs by a Volmer-Heyrovsky mechanism with the first step being the RDS. Moreover, the apparent energy of activation calculated from the Tafel plots presented a value as high as 150 kJ mol-1, indicating the formation of the M-H intermediate that is characteristic for the Volmer step. On the other hand, the apparent energy of activation for the oxygen evolution reaction was found to be 106 kJ mol-1 suggesting that the RDS in this mechanism is the initial adsorption step. In this way, it was demonstrated that the interaction between water molecules and the electrode surface is strongly inhibited on BDD thus justifying the extended potential window observed for this material.

  18. 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 - others: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

  19. Controlling Physical and Chemical Bonding of Polypyrrole to Boron Doped Diamond by Surface Termination

    OpenAIRE

    Ukraintsev, Egor; Kromka, Alexander; Janssen, Wiebke; Haenen, Ken; Rezek, Bohuslav

    2013-01-01

    To elucidate and to control polypyrrole (PPy) attachment to diamond we electrochemically grow PPy layers on hydrogen- and oxygen-terminated boron doped diamonds (BDD). Atomic force microscopy (AFM) shows that the PPy layers have similar morphology (15 nm features) and thickness (> 5 nm) on H- and O-BDD. To resolve type of PPy-diamond bonding, scanning electron microscopy (SEM) is used to compare intensity of secondary electron emission from original BDD regions and regions where PPy was grown...

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  1. Doping Level of Boron-Doped Diamond Electrodes Controls the Grafting Density of Functional Groups for DNA Assays.

    Science.gov (United States)

    Švorc, Ĺubomír; Jambrec, Daliborka; Vojs, Marian; Barwe, Stefan; Clausmeyer, Jan; Michniak, Pavol; Marton, Marián; Schuhmann, Wolfgang

    2015-09-02

    The impact of different doping levels of boron-doped diamond on the surface functionalization was investigated by means of electrochemical reduction of aryldiazonium salts. The grafting efficiency of 4-nitrophenyl groups increased with the boron levels (B/C ratio from 0 to 20,000 ppm). Controlled grafting of nitrophenyldiazonium was used to adjust the amount of immobilized single-stranded DNA strands at the surface and further on the hybridization yield in dependence on the boron doping level. The grafted nitro functions were electrochemically reduced to the amine moieties. Subsequent functionalization with a succinic acid introduced carboxyl groups for subsequent binding of an amino-terminated DNA probe. DNA hybridization significantly depends on the probe density which is in turn dependent on the boron doping level. The proposed approach opens new insights for the design and control of doped diamond surface functionalization for the construction of DNA hybridization assays.

  2. Characteristics of deposited boron doping diamond on tungsten carbide insert by MPECVD

    Science.gov (United States)

    Kim, Jong Seok; Park, Yeong Min; Kim, Jeong Wan; Tulugan, Kelimu; Kim, Tae Gyu

    2015-03-01

    Diamond-coated cutting tools are used primarily for machining non-ferrous materials such as aluminum-silicon alloys, copper alloys, fiber-reinforced polymers, green ceramics and graphite. Because the tool life of cemented carbide cutting tool is greatly improved by diamond coating, and typically more than 10 times of the tool life is obtained. However, research of boron-doped diamond (BDD) coating tool has not been fully researched yet. In this study, we have succeeded to make boron-doped microcrystalline and nanocrystalline diamond-coated Co-cemented tungsten carbide (WC-Co) inserts. Microcrystalline BDD thin film is deposited on WC-Co insert by using microwave plasma enhanced chemical vapor deposition (MPECVD) method. Scanning electron microscope (SEM) and Raman spectroscopy are used to characterize the as-deposited diamond films.1,2

  3. Boron-doped diamond electrode: synthesis, characterization, functionalization and analytical applications.

    Science.gov (United States)

    Luong, John H T; Male, Keith B; Glennon, Jeremy D

    2009-10-01

    In recent years, conductive diamond electrodes for electrochemical applications have been a major focus of research and development. The impetus behind such endeavors could be attributed to their wide potential window, low background current, chemical inertness, and mechanical durability. Several analytes can be oxidized by conducting diamond compared to other carbon-based materials before the breakdown of water in aqueous electrolytes. This is important for detecting and/or identifying species in solution since oxygen and hydrogen evolution do not interfere with the analysis. Thus, conductive diamond electrodes take electrochemical detection into new areas and extend their usefulness to analytes which are not feasible with conventional electrode materials. Different types of diamond electrodes, polycrystalline, microcrystalline, nanocrystalline and ultrananocrystalline, have been synthesized and characterized. Of particular interest is the synthesis of boron-doped diamond (BDD) films by chemical vapor deposition on various substrates. In the tetrahedral diamond lattice, each carbon atom is covalently bonded to its neighbors forming an extremely robust crystalline structure. Some carbon atoms in the lattice are substituted with boron to provide electrical conductivity. Modification strategies of doped diamond electrodes with metallic nanoparticles and/or electropolymerized films are of importance to impart novel characteristics or to improve the performance of diamond electrodes. Biofunctionalization of diamond films is also feasible to foster several useful bioanalytical applications. A plethora of opportunities for nanoscale analytical devices based on conducting diamond is anticipated in the very near future.

  4. Influence of boron content on the morphological, spectral, and electroanalytical characteristics of anodically oxidized boron-doped diamond electrodes

    Czech Academy of Sciences Publication Activity Database

    Schwarzová-Pecková, K.; Vosáhlová, J.; Barek, J.; Šloufová, I.; Pavlova, Ewa; Petrák, Václav; Zavázalová, J.

    2017-01-01

    Roč. 243, 20 July (2017), s. 170-182 ISSN 0013-4686 R&D Projects: GA TA ČR(CZ) TE01020118 Institutional support: RVO:61389013 ; RVO:68378271 Keywords : 2-aminobiphenyl * boron content * boron-doped diamond Subject RIV: CD - Macromolecular Chemistry; CG - Electrochemistry (FZU-D) OBOR OECD: Polymer science; Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis) (FZU-D) Impact factor: 4.798, year: 2016

  5. The Effects of Boron Doping on Residual Stress of Hfcvd Diamond Film for Mems Applications

    Science.gov (United States)

    Zhao, Tianqi; Wang, Xinchang; Sun, Fanghong

    In this study, the residual stress of boron-doped diamond (BDD) films is investigated as a function of boron doping level using X-ray diffraction (XRD) analysis. Boron doping level is controlled from 1000ppm to 9000ppm by dissolving trimethyl borate into acetone. BDD films are deposited on silicon wafers using a bias-enhanced hot filament chemical vapor deposition (BE-HFCVD) system. Residual stress calculated by sin2 ψ method varies linearly from ‑2.4GPa to ‑1.1GPa with increasing boron doping level. On the BDD film of ‑1.75GPa, free standing BDD cantilevers are fabricated by photolithography and ICP-RIE processes, then tested by laser Doppler vibrometer (LDV). A cantilever with resonant frequency of 183KHz and Q factor of 261 in the air is fabricated.

  6. 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.

  7. 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

    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. 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. 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. 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.

  8. 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: 4.449, year: 2015

  9. Electrochemical protein cleavage in a microfluidic cell with integrated boron doped diamond electrodes

    NARCIS (Netherlands)

    van den Brink, Floris Teunis Gerardus; Zhang, Tao; Ma, Liwei; Odijk, Mathieu; Olthuis, Wouter; Permentier, Hjalmar P.; Bischoff, Rainer P.H.; van den Berg, Albert

    2015-01-01

    We present a microfluidic electrochemical cell with integrated boron doped diamond (BDD) electrodes which is designed for high electrochemical conversion efficiencies. With our newest developments, we aim to exploit the benefits of BDD as a novel electrode material to conduct tyrosine- and

  10. 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: 2.125, year: 2015

  11. Boron-Doped Diamond Electrodes for the Electrochemical Oxidation and Cleavage of Peptides

    NARCIS (Netherlands)

    Roeser, Julien; Alting, Niels F. A.; Permentier, Hjalmar P.; Bruins, Andries P.; Bischoff, Rainer

    2013-01-01

    Electrochemical oxidation of peptides and proteins is traditionally performed on carbon-based electrodes. Adsorption caused by the affinity of hydrophobic and aromatic amino acids toward these surfaces leads to electrode fouling. We compared the performance of boron-doped diamond (BDD) and glassy

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

    Science.gov (United States)

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

    2013-07-25

    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.

  13. 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.

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

    Science.gov (United States)

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

    2013-01-01

    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. PMID:28811426

  15. 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

  16. 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.

  17. 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: 0.407, year: 2015

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

    OpenAIRE

    Yu, Yuan; Zhou, Yanli; Wu, Liangzhuan; Zhi, Jinfang

    2012-01-01

    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, sensitiv...

  19. 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 - others: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: 2.125, year: 2015

  20. 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...

  1. Development of Conductive Boron-Doped Diamond Electrode: A microscopic, Spectroscopic, and Voltammetric Study

    Directory of Open Access Journals (Sweden)

    Kevin E. Bennet

    2013-12-01

    Full Text Available Building on diamond characteristics such as hardness, chemical inertness and low electron emission threshold voltage, the current microscopic, spectroscopic and voltammetric investigations are directed towards improving the properties of electrode coating materials for their future use in clinical studies of deep brain stimulation via fast-scan cyclic voltammetry (FSCV. In this study we combine the capabilities of confocal Raman mapping in providing detailed and accurate analysis of local distributions of material constituents in a series of boron-doped polycrystalline diamond films grown by chemical vapor deposition, with information from the more conventional techniques of scanning electron microscopy (SEM and infrared absorption spectroscopy. Although SEM images show a uniform distribution of film crystallites, they have the limitation of being unable to differentiate the distribution of boron in the diamond. Values of 1018–1021 atoms/cm3 of boron content have been estimated from the absorption coefficient of the 1290 cm−1 infrared absorption band and from the 500 cm−1 Raman vibration. The observed accumulation of boron atoms and carbon sp2 impurities at the grain boundaries suggests that very high doping levels do not necessarily contribute to improvement of the material’s conductivity, corroborating with voltammetric data. FSCV results also indicate an enhanced stability of analyte detection.

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

    International Nuclear Information System (INIS)

    Stanković, Dalibor M.; Kalcher, Kurt

    2015-01-01

    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 (R 2 = 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

  3. Boron doped diamond electrode for the wastewater treatment

    Directory of Open Access Journals (Sweden)

    Alfaro Marco Antonio Quiroz

    2006-01-01

    Full Text Available 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.

  4. Boron doped diamond electrode for the wastewater treatment

    International Nuclear Information System (INIS)

    Quiroz Alfaro, Marco Antonio; Ferro, Sergio; Martinez-Huitle, Carlos Alberto; Vong, Yunny Meas

    2006-01-01

    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)

  5. Boron-doped diamond synthesized at high-pressure and high-temperature with metal catalyst

    Science.gov (United States)

    Shakhov, Fedor M.; Abyzov, Andrey M.; Kidalov, Sergey V.; Krasilin, Andrei A.; Lähderanta, Erkki; Lebedev, Vasiliy T.; Shamshur, Dmitriy V.; Takai, Kazuyuki

    2017-04-01

    The boron-doped diamond (BDD) powder consisting of 40-100 μm particles was synthesized at 5 GPa and 1500-1600 °C from a mixture of 50 wt% graphite and 50 wt% Ni-Mn catalyst with an addition of 1 wt% or 5 wt% boron powder. The size of crystal domains of doped and non-doped diamond was evaluated as a coherent scattering region by X-ray diffraction (XRD) and using small-angle neutron scattering (SANS), being ≥180 nm (XRD) and 100 nm (SANS). Magnetic impurities of NiMnx originating from the catalyst in the synthesis, which prevent superconductivity, were detected by magnetization measurements at 2-300 K. X-ray photoelectron spectroscopy, the temperature dependence of the resistivity, XRD, and Raman spectroscopy reveal that the concentration of electrically active boron is as high as (2±1)×1020 cm-3 (0.1 at%). To the best of our knowledge, this is the highest boron content for BDD synthesized in high-pressure high-temperature process with metal catalysts.

  6. Vertically aligned nanowires from boron-doped diamond.

    Science.gov (United States)

    Yang, Nianjun; Uetsuka, Hiroshi; Osawa, Eiji; Nebel, Christoph E

    2008-11-01

    Vertically aligned diamond nanowires with controlled geometrical properties like length and distance between wires were fabricated by use of nanodiamond particles as a hard mask and by use of reactive ion etching. The surface structure, electronic properties, and electrochemical functionalization of diamond nanowires were characterized by atomic force microscopy (AFM) and scanning tunneling microscopy (STM) as well as electrochemical techniques. AFM and STM experiments show that diamond nanowire etched for 10 s have wire-typed structures with 3-10 nm in length and with typically 11 nm spacing in between. The electrode active area of diamond nanowires is enhanced by a factor of 2. The functionalization of nanowire tips with nitrophenyl molecules is characterized by STM on clean and on nitrophenyl molecule-modified diamond nanowires. Tip-modified diamond nanowires are promising with respect to biosensor applications where controlled biomolecule bonding is required to improve chemical stability and sensing significantly.

  7. Friction and wear performance of boron doped, undoped microcrystalline and fine grained composite diamond films

    Science.gov (United States)

    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. The Abrasion Resistance and Adhesion of Hfcvd Boron and Silicon-Doped Diamond Films on WC-Co Drawing Dies

    Science.gov (United States)

    Wang, Liang; Liu, Jinfei; Tang, Tang; Sun, Fanghong; Xie, Nan

    Diamond films have been deposited on the interior hole surface of cobalt-cemented tungsten carbide (WC-Co) drawing dies from acetone, trimethyl borate (C3H9BO3), tetraethoxysilane (C8H20O4Si, TEOS) and hydrogen mixture by hot-filament chemical vapor deposition (HFCVD) method. The structures and quality of as-deposited diamond films are characterized with field-emission scanning electron microscopy (FESEM) and Raman spectroscopy. The abrasion ratio and the adhesive strength of as-deposited diamond films are evaluated by copper wire drawing tests and ultrasonic lapping tests, respectively. The results suggest that diamond films with small grain size and high growth rate can be obtained due to the mutual effects of boron and silicon impurities in the gas phases. The results of ultrasonic lapping tests show that diamond films doped with boron and/or silicon can bear the severe erosion of the large diamond powder. Diamond films peeling off within the reduction zone of the drawing dies cannot be observed after testing of 2h. The abrasion ratio of boron and silicon-added diamond films is five times that of diamond films without any addition. Adding boron and/or silicon in the diamond films is proved to be an efficient way to obtain high-adhesive-strength and high-abrasion-resistance diamond-coated drawing dies.

  9. Boron-doped nanocrystalline diamond microelectrode arrays monitor cardiac action potentials.

    Science.gov (United States)

    Maybeck, Vanessa; Edgington, Robert; Bongrain, Alexandre; Welch, Joseph O; Scorsone, Emanuel; Bergonzo, Philippe; Jackman, Richard B; Offenhäusser, Andreas

    2014-02-01

    The expansion of diamond-based electronics in the area of biological interfacing has not been as thoroughly explored as applications in electrochemical sensing. However, the biocompatibility of diamond, large safe electrochemical window, stability, and tunable electronic properties provide opportunities to develop new devices for interfacing with electrogenic cells. Here, the fabrication of microelectrode arrays (MEAs) with boron-doped nanocrystalline diamond (BNCD) electrodes and their interfacing with cardiomyocyte-like HL-1 cells to detect cardiac action potentials are presented. A nonreductive means of structuring doped and undoped diamond on the same substrate is shown. The resulting BNCD electrodes show high stability under mechanical stress generated by the cells. It is shown that by fabricating the entire surface of the MEA with NCD, in patterns of conductive doped, and isolating undoped regions, signal detection may be improved up to four-fold over BNCD electrodes passivated with traditional isolators. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. 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.

  11. Influence of modified carbon substrate on boron doped ultrananocrystalline diamond deposition

    Science.gov (United States)

    Sizuka Oishi, Silvia; Mieko Silva, Lilian; Cocchieri Botelho, Edson; Cerqueira Rezende, Mirabel; Alves Cairo, Carlos Alberto; Gomes Ferreira, Neidenêi

    2018-02-01

    Boron doped ultrananocrystalline diamond (B-UNCD) growth was studied on modified reticulated vitreous carbon (RVC) produced from poly(furfuryl alcohol) (PFA) resin with sodium hydroxide additions at two different heat treatment temperatures. The different amounts of NaOH in PFA (up to reaching pH values of around 3, 5, 7, and 9) aimed to neutralize the acid catalyst and to increase the PFA storage life. Besides, this procedure was responsible for increasing the oxygen content of RVC samples. Thus, the effect of carbon and oxygen coming from the substrates in addition to their different graphitization indexes on diamond morphology, grain size, preferential growth and boron doping level were investigated by FEG-SEM, x-ray diffraction and Raman spectroscopy. Therefore, B-UNCD films were successfully grown on RVC with pH values of 3, 5, 7, and 9 heat treated at 1000 and 1700 °C. Nonetheless, the higher oxygen amount during B-UNCD growth for samples with pH 7 and 9 heat treated at 1000 °C was responsible for the RVC surface etching and the decrease in the boron concentration of such samples. The cross section images showed that B-UNCD infiltrated at around 0.9 mm in depth of RVC samples while carbon nanowalls were observed mainly on RVC samples heat treated at 1000 °C for all pH range studied.

  12. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Bo, E-mail: 357436235@qq.com [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Yu, Zhiming, E-mail: zhiming@csu.edu.cn [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Wei, Qiuping, E-mail: qiupwei@csu.edu.cn [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Long, HangYu, E-mail: 55686385@qq.com [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Xie, Youneng, E-mail: 1187272844@qq.com [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Wang, Yijia, E-mail: 503630433@qq.com [School of Materials Science and Engineering, Central South University, Changsha 410083 (China)

    2016-07-30

    Highlights: • High quality boron-doped diamond film electrodes were synthesized on Nb substrates. • Electrochemical oxidation on boron-doped diamond anode is an effective method for treating landfill leachate concentrates. • Optimal operating conditions for electrochemical oxidation of landfill leachate concentrates is determined. • 87.5% COD removal and 74.06% NH{sub 3}−N removal were achieved after 6 h treatment. - Abstract: 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 (NH{sub 3}−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{sup −2}, pH 5.16, flow velocity 6 L h{sup −1}. Under these conditions, 87.5% COD and 74.06% NH{sub 3}−N removal were achieved after 6 h treatment, with specific energy consumption of 223.2 kWh m{sup −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.

  14. Polycrystalline boron-doped diamond electrodes for electrocatalytic and electrosynthetic applications.

    Science.gov (United States)

    Ivandini, Tribidasari A; Einaga, Yasuaki

    2017-01-24

    Boron-doped diamond (BDD) electrodes are recognized as being superior to other electrode materials due to their outstanding chemical and dimensional stability, their exceptionally low background current, the extremely wide potential window for water electrolysis that they have, and their excellent biocompatibility. However, whereas these properties have been utilized in the rapid development of electroanalytical applications, very few studies have been done in relation to their applications in electrocatalysis or electrosynthesis. In this report, following on from reports of the electrosynthesis of various products through anodic and cathodic reactions using BDD electrodes, the potential use of these electrodes in electrosynthesis is discussed.

  15. Controlling physical and chemical bonding of polypyrrole to boron doped diamond by surface termination

    Czech Academy of Sciences Publication Activity Database

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

    2013-01-01

    Roč. 8, č. 1 (2013), s. 17-26 ISSN 1452-3981 R&D Projects: GA ČR(CZ) GBP108/12/G108; GA ČR GAP108/12/0996 Grant - others:EU FP7 Marie Curie ITN MATCON(XE) PITN-GA-2009-238201 Institutional support: RVO:68378271 Keywords : electrochemical growth * polypyrrole * boron doped diamond * scanning electron microscopy * Kelvin force microscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.956, year: 2013 http://www.electrochemsci.org/papers/vol8/80100017.pdf

  16. 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

  17. Porous boron doped diamonds as metal-free catalysts for the oxygen reduction reaction in alkaline solution

    Science.gov (United States)

    Suo, Ni; Huang, Hao; Wu, Aimin; Cao, Guozhong; Hou, Xiaoduo; Zhang, Guifeng

    2018-05-01

    Porous boron doped diamonds (BDDs) were obtained on foam nickel substrates with a porosity of 80%, 85%, 90% and 95% respectively by hot filament chemical vapor deposition (HFCVD) technology. Scanning electron microscopy (SEM) reveals that uniform and compact BDDs with a cauliflower-like morphology have covered the overall frame of the foam nickel substrates. Raman spectroscopy shows that the BDDs have a poor crystallinity due to heavily doping boron. X-ray photoelectron spectroscopy (XPS) analysis effectively demonstrates that boron atoms can be successfully incorporated into the crystal lattice of diamonds. Electrochemical measurements indicate that the oxygen reduction potential is unaffected by the specific surface area (SSA), and both the onset potential and the limiting diffusion current density are enhanced with increasing SSA. It is also found that the durability and methanol tolerance of the boron doped diamond catalysts are attenuated as the increasing of SSA. The SSA of the catalyst is directly proportional to the oxygen reduction activity and inversely to the durability and methanol resistance. These results provide a reference to the application of porous boron doped diamonds as potential cathodic catalysts for the oxygen reduction reaction in alkaline solution by adjusting the SSA.

  18. 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.

  19. 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 EU Projects: European Commission(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

  20. Boron doped diamond synthesized from detonation nanodiamond in a C-O-H fluid at high pressure and high temperature

    Science.gov (United States)

    Shakhov, Fedor M.; Abyzov, Andrey M.; Takai, Kazuyuki

    2017-12-01

    Boron doped diamond (BDD) was synthesized under high pressure and high temperature (HPHT) of 7 GPa, 1230 °C in a short time of 10 s from a powder mixtures of detonation nanodiamond (DND), pentaerythritol C5H8(OH)4 and amorphous boron. SEM, TEM, XRD, XPS, FTIR and Raman spectroscopy indicated that BDD nano- and micro-crystals have formed by consolidation of DND particles (4 nm in size). XRD showed the enlargement of crystallites size to 6-80 nm and the increase in diamond lattice parameter by 0.02-0.07% without appearance of any microstrains. Raman spectroscopy was used to estimate the content of boron atoms embedded in the diamond lattice. It was found that the Raman diamond peak shifts significantly from 1332 cm-1 to 1290 cm-1 without appearance of any non-diamond carbon. The correlation between Raman peak position, its width, and boron content in diamond is proposed. Hydrogenated diamond carbon in significant amount was detected by IR spectroscopy and XPS. Due to the doping with boron content of about 0.1 at%, the electrical conductivity of the diamond achieved approximately 0.2 Ω-1 cm-1. Reaction mechanism of diamond growth (models of recrystallization and oriented attachment) is discussed, including the initial stages of pentaerythritol pyrolysis and thermal desorption of functional groups from the surface of DND particles with the generation of supercritical fluid of low-molecular substances (H2O, CH4, CO, CO2, etc.), as well as byproducts formation (B2O3, B4C).

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

    DEFF Research Database (Denmark)

    Meijs, Suzan; McDonald, Matthew; Sørensen, Søren

    2015-01-01

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

  2. 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 Impact factor: 4.803, year: 2015

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

    International Nuclear Information System (INIS)

    Kavan, Ladislav; Vlckova Zivcova, Zuzana; Petrak, Vaclav; Frank, Otakar; Janda, Pavel; Tarabkova, Hana; Nesladek, Milos; Mortet, Vincent

    2015-01-01

    Highlights: • B-doped diamond is nanostructured by corrosion-driven modifications occurring at carbonaceous impurity sites (sp 2 -carbons). • The electrochemical oxidation partly transforms a hydrogen-terminated diamond surface to O-terminated one, but the electrocatalytic activity of plasmatically O-terminated diamond is not achieved. • In contrast to all usual sp 2 carbons, the Raman spectra of B-doped diamond electrodes do not change upon electrochemical charging/discharging. - Abstract: Comparative studies of boron-doped diamonds electrodes (polycrystalline, single-crystalline, H-/O-terminated, and with different sp 3 /sp 2 ratios) indicate morphological modifications of diamond which are initiated by corrosion at nanoscale. In-situ electrochemical AFM imaging evidences that the textural changes start at non-diamond carbonaceous impurity sites treated at high positive potentials (>2.2 V vs. Ag/AgCl). The primary perturbations subsequently develop into sub-micron-sized craters. Raman spectroscopy shows that the primary erosion site is graphite-like (sp 2 -carbon), which is preferentially removed by anodic oxidation. Other non-diamond impurity, viz. tetrahedral amorphous carbon (t-aC), is less sensitive to oxidative decomposition. The diamond-related Raman features, including the B-doping-assigned modes, are intact during reversible electrochemical charging/discharging, which is a salient difference from all usual sp 2 -carbons. The electrochemical oxidation partly transforms a hydrogen-terminated diamond surface to O-terminated one, but the electrocatalytic activity of plasmatically O-terminated diamond is not achieved for a model redox couple, Fe 3+/2+ . Electrochemical impedance spectra were fitted to six different equivalent circuits. The determination of acceptor concentrations is feasible even for highly-doped diamond electrodes.

  4. Boron-doped diamond nano/microelectrodes for bio-sensing and in vitro measurements

    Science.gov (United States)

    Dong, Hua; Wang, Shihua; Galligan, James J.; Swain, Greg M.

    2015-01-01

    Since the fabrication of the first diamond electrode in the mid 1980s, repid progress has been made on the development and application of this new type of electrode material. Boron-doped diamond (BDD) electrodes exhibit outstanding properties compared to oxygen-containing sp2 carbon electrodes. These properties make BDD electrodes an ideal choice for use in complex samples. In recent years, BDD microelectrodes have been applied to in vitro and in vivo measurements of biological molecules in animals, tissues and cells. This review will summarize recent progress in the development and applications of BDD electrodes in bio-sensing and in vitro measurements of biomolecules. In the first section, the methods for BDD nanocrystalline diamond film deposition and BDD microelectrodes preparation are described. This is followed by a description and discussion of several approaches for characterization of the BDD electrode surface structure, morphology, and electrochemical activity. Further, application of BDD microelectrodes for use in the in vitro analysis of norepinephrine (NE), serotonin (5-HT), nitric oxide (NO), histamine, and adenosine from tissues are summarized and finally some of the remaining challenges are discussed. PMID:21196394

  5. 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.

  6. Fabrication of porous boron-doped diamond on SiO.sub.2./sub. fiber templates

    Czech Academy of Sciences Publication Activity Database

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

    2017-01-01

    Roč. 114, Jan (2017), s. 457-464 ISSN 0008-6223 R&D Projects: GA MŠk LO1409; GA MŠk LM2015088; GA ČR GA13-31783S Grant - others:FUNBIO(XE) CZ.2.16/3.1.00/21568; AV ČR(CZ) Fellowship J. E. Purkyně Institutional support: RVO:68378271 ; RVO:61388955 Keywords : boron-doped diamond * electrochemical properties Subject RIV: BM - Solid Matter Physics ; Magnetism; CG - Electrochemistry (UFCH-W) OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.); Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis) (UFCH-W) Impact factor: 6.337, year: 2016

  7. Chemical Modification of Boron-Doped Diamond Electrodes for Applications to Biosensors and Biosensing.

    Science.gov (United States)

    Svítková, Jana; Ignat, Teodora; Švorc, Ľubomír; Labuda, Ján; Barek, Jiří

    2016-05-03

    Boron-doped diamond (BDD) is a prospective electrode material that possesses many exceptional properties including wide potential window, low noise, low and stable background current, chemical and mechanical stability, good biocompatibility, and last but not least exceptional resistance to passivation. These characteristics extend its usability in various areas of electrochemistry as evidenced by increasing number of published articles over the past two decades. The idea of chemically modifying BDD electrodes with molecular species attached to the surface for the purpose of creating a rational design has found promising applications in the past few years. BDD electrodes have appeared to be excellent substrate materials for various chemical modifications and subsequent application to biosensors and biosensing. Hence, this article presents modification strategies that have extended applications of BDD electrodes in electroanalytical chemistry. Different methods and steps of surface modification of this electrode material for biosensing and construction of biosensors are discussed.

  8. 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.

  9. 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.

  10. Fabrication of a Microfluidic Device with Boron-doped Diamond Electrodes for Electrochemical Analysis

    International Nuclear Information System (INIS)

    Watanabe, Takeshi; Shibano, Shuhei; Maeda, Hideto; Sugitani, Ai; Katayama, Michinobu; Matsumoto, Yoshinori; Einaga, Yasuaki

    2016-01-01

    A prototype microfluidic device using boron-doped diamond (BDD) electrodes patterned on an alumina chip was designed and fabricated. Electrochemical microfluidic devices have advantages in that the amount of sample required is small, the measurement throughput is high, different functions can be integrated on a single device, and they are highly durable. In using the device for the flow injection analysis of oxalic acid, the application of a brief conditioning step ensured that the reproducibility of the current signal was excellent. Furthermore, the fabricated system also performed as a prototype of “elimination-detection flow system”, in which interfering species are eliminated using “elimination electrodes” prior to the species reaching the “detection electrode”. The fabricated device reduced the current due to interfering species by 78%. Designs of devices to improve this efficiency are also discussed.

  11. Simultaneous detection of iodine and iodide on boron doped diamond electrodes.

    Science.gov (United States)

    Fierro, Stéphane; Comninellis, Christos; Einaga, Yasuaki

    2013-01-15

    Individual and simultaneous electrochemical detection of iodide and iodine has been performed via cyclic voltammetry on boron doped diamond (BDD) electrodes in a 1M NaClO(4) (pH 8) solution, representative of typical environmental water conditions. It is feasible to compute accurate calibration curve for both compounds using cyclic voltammetry measurements by determining the peak current intensities as a function of the concentration. A lower detection limit of about 20 μM was obtained for iodide and 10 μM for iodine. Based on the comparison between the peak current intensities reported during the oxidation of KI, it is probable that iodide (I(-)) is first oxidized in a single step to yield iodine (I(2)). The latter is further oxidized to obtain IO(3)(-). This technique, however, did not allow for a reasonably accurate detection of iodate (IO(3)(-)) on a BDD electrode. Copyright © 2012 Elsevier B.V. All rights reserved.

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

    International Nuclear Information System (INIS)

    Zhang Chunyong; Yang Lijiao; Rong Fei; Fu Degang; Gu Zhongze

    2012-01-01

    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 Na 2 SO 4 , 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-05-05

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

  14. Electrochemical grafting of boron-doped single-crystalline chemical vapor deposition diamond with nitrophenyl molecules.

    Science.gov (United States)

    Uetsuka, Hiroshi; Shin, Dongchan; Tokuda, Norio; Saeki, Kazuhiko; Nebel, Christoph E

    2007-03-13

    The growth of covalently bonded nitrophenyl layers on atomically smooth boron-doped single-crystalline diamond surfaces is characterized using cyclic voltammetric attachment and constant-potential grafting by electrochemical reduction of aryl diazonium salts. We apply atomic force microscopy (AFM) in contact mode to remove phenyl layers and measure phenyl layer thicknesses by oscillatory AFM. Angle-resolved X-ray photoelectron spectroscopy is applied to reveal the bonding arrangement of phenyl molecules, and transient current measurements during the grafting are used to investigate the dynamics of chemical bonding. Nitrophenyl groups at an initial stage of attachment grow three-dimensional (3D), forming layers of varying heights and densities. Layer thicknesses of up to 80 A are detected for cyclic voltammetry attachment after five cycles, whereas the layer becomes denser and only about 25 A thick in the case of constant-potential attachment. No monomolecular closed layer can be detected. The data are discussed taking into account established growth models. Redox systems such as Fe(CN)63-/4- and Ru(NH3)62+/3+ are used to probe the electrochemical barrier properties of nitrophenyl groups grafted onto diamond.

  15. Kinetics and mechanism of the deep electrochemical oxidation of sodium diclofenac on a boron-doped diamond electrode

    Science.gov (United States)

    Vedenyapina, M. D.; Borisova, D. A.; Rosenwinkel, K.-H.; Weichgrebe, D.; Stopp, P.; Vedenyapin, A. A.

    2013-08-01

    The kinetics and mechanism of the deep oxidation of sodium diclofenac on a boron-doped diamond electrode are studied to develop a technique for purifying wastewater from pharmaceutical products. The products of sodium diclofenac electrolysis are analyzed using cyclic voltammetry and nuclear magnetic resonance techniques. It is shown that the toxicity of the drug and products of its electrolysis decreases upon its deep oxidation.

  16. Electrochemical evaluation and determination of antiretroviral drug fosamprenavir using boron-doped diamond and glassy carbon electrodes.

    Science.gov (United States)

    Gumustas, Mehmet; Ozkan, Sibel A

    2010-05-01

    Fosamprenavir is a pro-drug of the antiretroviral protease inhibitor amprenavir and is oxidizable at solid electrodes. The anodic oxidation behavior of fosamprenavir was investigated using cyclic and linear sweep voltammetry at boron-doped diamond and glassy carbon electrodes. In cyclic voltammetry, depending on pH values, fosamprenavir showed one sharp irreversible oxidation peak or wave depending on the working electrode. The mechanism of the oxidation process was discussed. The voltammetric study of some model compounds allowed elucidation of the possible oxidation mechanism of fosamprenavir. The aim of this study was to determine fosamprenavir levels in pharmaceutical formulations and biological samples by means of electrochemical methods. Using the sharp oxidation response, two voltammetric methods were described for the determination of fosamprenavir by differential pulse and square-wave voltammetry at the boron-doped diamond and glassy carbon electrodes. These two voltammetric techniques are 0.1 M H(2)SO(4) and phosphate buffer at pH 2.0 which allow quantitation over a 4 x 10(-6) to 8 x 10(-5) M range using boron-doped diamond and a 1 x 10(-5) to 1 x 10(-4) M range using glassy carbon electrodes, respectively, in supporting electrolyte. All necessary validation parameters were investigated and calculated. These methods were successfully applied for the analysis of fosamprenavir pharmaceutical dosage forms, human serum and urine samples. The standard addition method was used in biological media using boron-doped diamond electrode. No electroactive interferences from the tablet excipients or endogenous substances from biological material were found. The results were statistically compared with those obtained through an established HPLC-UV technique; no significant differences were found between the voltammetric and HPLC methods.

  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 - others: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. 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. 90-1-12 ISSN 0957-4530 R&D Projects: GA MŠk LO1409 Grant - others: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: 2.325, year: 2016

  19. Boron-doped diamond heater and its application to large-volume, high-pressure, and high-temperature experiments.

    Science.gov (United States)

    Shatskiy, Anton; Yamazaki, Daisuke; Morard, Guillaume; Cooray, Titus; Matsuzaki, Takuya; Higo, Yuji; Funakoshi, Ken-ichi; Sumiya, Hitoshi; Ito, Eiji; Katsura, Tomoo

    2009-02-01

    A temperature of 3500 degrees C was generated using a diamond resistance heater in a large-volume Kawai-type high-pressure apparatus. Re and LaCrO(3) have conventionally been used for heaters in high-pressure studies but they cannot generate temperatures higher than 2900 degrees C and make in situ x-ray observations difficult due to their high x-ray absorption. Using a boron-doped diamond heater overcomes these problems and achieves stable temperature generation for pressure over 10 GPa. The heater starting material is a cold-compressed mixture of graphite with boron used to avoid the manufacturing difficulties due to the extreme hardness of diamond. The diamond heater was synthesized in situ from the boron-graphite mixture at temperature of 1600+/-100 degrees C and pressure of 20 GPa. By using the proposed technique, we have employed the diamond heater for high-temperature generation in a large-volume high-pressure apparatus. Achievement of temperatures above 3000 degrees C allows us to measure the melting points of the important constituents in earth's mantle (MgSiO(3), SiO(2), and Al(2)O(3)) and core (Fe and Ni) at extremely high pressures.

  20. OSL and TL dosimeter characterization of boron doped CVD diamond films

    Science.gov (United States)

    Gonçalves, J. A. N.; Sandonato, G. M.; Meléndrez, R.; Chernov, V.; Pedroza-Montero, M.; De la Rosa, E.; Rodríguez, R. A.; Salas, P.; Barboza-Flores, M.

    2005-04-01

    Natural diamond is an exceptional prospect for clinical radiation dosimetry due to its tissue-equivalence properties and being chemically inert. The use of diamond in radiation dosimetry has been halted by the high market price; although recently the capability of growing high quality CVD diamond has renewed the interest in using diamond films as radiation dosimeters. In the present work we have characterized the dosimetric properties of diamond films synthesized by the HFCVD method. The thermoluminescence and the optically stimulated luminescence of beta exposed diamond sample containing a B/C 4000 ppm doping presents excellent properties suitable for dosimetric applications with β-ray doses up to 3.0 kGy. The observed OSL and TL performance is reasonable appropriate to justify further investigation of diamond films as dosimeters for ionizing radiation, specially in the radiotherapy field where very well localized and in vivo and real time radiation dose applications are essential.

  1. 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.

  2. Mercury detection at boron doped diamond electrodes using a rotating disk technique

    Energy Technology Data Exchange (ETDEWEB)

    Manivannan, A.; Ramakrishnan, L.; Seehra, M.S.; Granite, E.; Butler, J.E.; Tryk, D.A.; Fujishima, A. [West Virginia University, Morgantown, WV (United States)

    2005-04-01

    Quantification of mercury ions at the ppt level is reported using highly boron-doped diamond (BDD) film electrodes by differential pulse voltammetry (DPV). The DPV experiments were performed in nitrate, thiocyanate and chloride media. Investigation in chloride medium is important since practical samples usually contain chloride impurities. The formation of calomel in a chloride medium on the BDD surface is avoided by the co-deposition of purposely-added gold (3 ppm) during DPV detection. Excellent linear calibration plots have been obtained in all media for ppb ranges. Mercury in the 0.005-50 ppb range has been detected using a rotating disk electrode (RDE) technique in real samples (KCl impinger solutions) prepared from flue gas released by a pilot-scale coal-fired combustion facility. A portable instrument has also been used for the detection of mercury efficiently. These studies have demonstrated that BDD mounted in an RDE system together with gold co-deposition is able to detect mercury with sufficient sensitivity for practical analysis of environmental samples.

  3. Anodic oxidation of textile wastewaters on boron-doped diamond electrodes.

    Science.gov (United States)

    Abdessamad, NourElHouda; Akrout, Hanene; Bousselmi, Latifa

    2015-01-01

    The objective of this study is to investigate the potential application of the anodic oxidation (AO) on two electrolytic cells (monopolar (Cell 1) and bipolar (Cell 2)) containing boron-doped diamond electrodes on the treatment of real textile effluents to study the reuse possibility of treated wastewater in the textile industry process. AO is applied in the flocculation coagulation pretreatment of both upstream (BH) and downstream (BS) effluents. The chemical oxygen demand (COD) results show that the final COD removal obtained for the BH effluent in the case of Cell 1 and Cell 2 is 800 and 150 mg O₂L⁻¹ after 5 and 6 h of electrolysis, respectively. The treatments of the BS effluent allow for obtaining a final COD of 76 mg L⁻¹ for Cell 1 and a total mineralization for Cell 2. The obtained results demonstrate that the apparent mineralization kinetics of both effluents when using Cell 2 are about four times faster than the one obtained by Cell 1 and highlight the important contribution of the bipolar cell. Besides, the energy consumption values show that the treatment of the BH effluent by Cell 1 consumes 865 kWh kg COD⁻¹ against 411 kWh kg COD(-1) by Cell 2. Therefore, the use of Cell 2 decreases the energy cost by 2.1-6.65 times when compared to Cell 1 in the case of the BH and BS effluent treatment, respectively.

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

    International Nuclear Information System (INIS)

    Tsantaki, Eleni; Velegraki, Theodora; Katsaounis, Alexandros; Mantzavinos, Dionissios

    2012-01-01

    The electrochemical oxidation of textile effluents over a boron-doped diamond anode was investigated in the present study. Experiments were conducted with a multi-component synthetic solution containing seventeen dyes and other auxiliary inorganics, as well as an actual effluent from a textile dyeing process. The effect of varying operating parameters, such as current density (4–50 mA/cm 2 ), electrolyte concentration (0.1–0.5 M HClO 4 ), 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.

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

    Science.gov (United States)

    Tsantaki, Eleni; Velegraki, Theodora; Katsaounis, Alexandros; Mantzavinos, Dionissios

    2012-03-15

    The electrochemical oxidation of textile effluents over a boron-doped diamond anode was investigated in the present study. Experiments were conducted with a multi-component synthetic solution containing seventeen dyes and other auxiliary inorganics, as well as an actual effluent from a textile dyeing process. The effect of varying operating parameters, such as current density (4-50 mA/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. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Parabens abatement from surface waters by electrochemical advanced oxidation with boron doped diamond anodes.

    Science.gov (United States)

    Domínguez, Joaquín R; Muñoz-Peña, Maria J; González, Teresa; Palo, Patricia; Cuerda-Correa, Eduardo M

    2016-10-01

    The removal efficiency of four commonly-used parabens by electrochemical advanced oxidation with boron-doped diamond anodes in two different aqueous matrices, namely ultrapure water and surface water from the Guadiana River, has been analyzed. Response surface methodology and a factorial, composite, central, orthogonal, and rotatable (FCCOR) statistical design of experiments have been used to optimize the process. The experimental results clearly show that the initial concentration of pollutants is the factor that influences the removal efficiency in a more remarkable manner in both aqueous matrices. As a rule, as the initial concentration of parabens increases, the removal efficiency decreases. The current density also affects the removal efficiency in a statistically significant manner in both aqueous matrices. In the water river aqueous matrix, a noticeable synergistic effect on the removal efficiency has been observed, probably due to the presence of chloride ions that increase the conductivity of the solution and contribute to the generation of strong secondary oxidant species such as chlorine or HClO/ClO - . The use of a statistical design of experiments made it possible to determine the optimal conditions necessary to achieve total removal of the four parabens in ultrapure and river water aqueous matrices.

  7. Anodic voltammetry of zolmitriptan at boron-doped diamond electrode and its analytical applications.

    Science.gov (United States)

    Uslu, B; Canbaz, D

    2010-04-01

    The electrooxidative behavior and determination of zolmitriptan at a boron-doped diamond electrode were investigated using cyclic, linear sweep, differential pulse and square wave voltammetric techniques. Zolmitriptan undergoes irreversible oxidation at a peak potential of about +0.9 V (vs Ag/AgCl/3 M KCl). DPV and SWV techniques are proposed for the determination of zolmitriptan in phosphate buffer at pH 3.03, which allows quantitation over the two different ranges (8 x 10(-7) - 8 x 10(-6) M and 1 x 10(-5) - 1 x 10(-4) M) in supporting electrolyte for both methods. A linear response was obtained in phosphate buffer over two different ranges (6 x 10(-7) - 8 x 10(-6) M and 1 x 10(-5) - 1 x 10(-4) M) for spiked serum samples at pH 3.03 for both techniques. The repeatability and reproducibility of the methods for all media were determined. The standard addition method was used in serum. Precision and accuracy were also checked in all media. No electroactive interferences from the excipients and endegenous substances were found in the pharmaceutical dosage form and the biological sample, respectively.

  8. Comparison of glassy carbon and boron doped diamond electrodes: Resistance to biofouling

    International Nuclear Information System (INIS)

    Trouillon, Raphael; O'Hare, Danny

    2010-01-01

    Carbon based electrodes are widely used for in vivo and in vitro electrochemical studies. In particular, monoamine neurochemistry has been investigated using carbon microfibre electrodes. Similarly, glassy carbon (GC) is the preferred material for many biochemical applications, such as electrochemical detection in chromatography. More recently, boron doped diamond (BDD) has been utilized for biosensing, as its carbon sp 3 structure is expected to provide better resistance to analyte fouling. However, the main factor limiting the use of electrochemical sensors for biological studies is the effect of the biological matrix. Indeed, in vivo or in situ measurements expose the sensor to a complex matrix of proteins, which adsorb on the sensing surface and interfere with the electrochemical measurements. Here, we compare the performance of three carbon based electrodes: GC, GC with low surface oxides and BDD. The redox species ruthenium(III) hexaammine (outer-sphere), ferrocyanide (surface sensitive) and the biologically significant dopamine have been investigated in protein and blood-mimicking matrices. Cyclic voltammetry and electrochemical impedance spectroscopy have been used to examine the effect of spectator molecules and reaction products on electrode mechanisms. Our results show that BDD generally exhibits the best performance for most conditions and reactions and should therefore be preferred for measurements in biologically fouling environments. Furthermore, surface oxides seem also to improve resistance of the GC electrode to biofouling.

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

    International Nuclear Information System (INIS)

    Zhao Xu; Hou Yining; Liu Huijuan; Qiang Zhimin; Qu Jiuhui

    2009-01-01

    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.

  10. 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.

  11. Boron-doped diamond semiconductor electrodes: Efficient photoelectrochemical CO2 reduction through surface modification

    Science.gov (United States)

    Roy, Nitish; Hirano, Yuiri; Kuriyama, Haruo; Sudhagar, Pitchaimuthu; Suzuki, Norihiro; Katsumata, Ken-ichi; Nakata, Kazuya; Kondo, Takeshi; Yuasa, Makoto; Serizawa, Izumi; Takayama, Tomoaki; Kudo, Akihiko; Fujishima, Akira; Terashima, Chiaki

    2016-01-01

    Competitive hydrogen evolution and multiple proton-coupled electron transfer reactions limit photoelectrochemical CO2 reduction in aqueous electrolyte. Here, oxygen-terminated lightly boron-doped diamond (BDDL) thin films were synthesized as a semiconductor electron source to accelerate CO2 reduction. However, BDDL alone could not stabilize the intermediates of CO2 reduction, yielding a negligible amount of reduction products. Silver nanoparticles were then deposited on BDDL because of their selective electrochemical CO2 reduction ability. Excellent selectivity (estimated CO:H2 mass ratio of 318:1) and recyclability (stable for five cycles of 3 h each) for photoelectrochemical CO2 reduction were obtained for the optimum silver nanoparticle-modified BDDL electrode at −1.1 V vs. RHE under 222-nm irradiation. The high efficiency and stability of this catalyst are ascribed to the in situ photoactivation of the BDDL surface during the photoelectrochemical reaction. The present work reveals the potential of BDDL as a high-energy electron source for use with co-catalysts in photochemical conversion. PMID:27892544

  12. Boron-doped diamond semiconductor electrodes: Efficient photoelectrochemical CO2 reduction through surface modification

    Science.gov (United States)

    Roy, Nitish; Hirano, Yuiri; Kuriyama, Haruo; Sudhagar, Pitchaimuthu; Suzuki, Norihiro; Katsumata, Ken-Ichi; Nakata, Kazuya; Kondo, Takeshi; Yuasa, Makoto; Serizawa, Izumi; Takayama, Tomoaki; Kudo, Akihiko; Fujishima, Akira; Terashima, Chiaki

    2016-11-01

    Competitive hydrogen evolution and multiple proton-coupled electron transfer reactions limit photoelectrochemical CO2 reduction in aqueous electrolyte. Here, oxygen-terminated lightly boron-doped diamond (BDDL) thin films were synthesized as a semiconductor electron source to accelerate CO2 reduction. However, BDDL alone could not stabilize the intermediates of CO2 reduction, yielding a negligible amount of reduction products. Silver nanoparticles were then deposited on BDDL because of their selective electrochemical CO2 reduction ability. Excellent selectivity (estimated CO:H2 mass ratio of 318:1) and recyclability (stable for five cycles of 3 h each) for photoelectrochemical CO2 reduction were obtained for the optimum silver nanoparticle-modified BDDL electrode at -1.1 V vs. RHE under 222-nm irradiation. The high efficiency and stability of this catalyst are ascribed to the in situ photoactivation of the BDDL surface during the photoelectrochemical reaction. The present work reveals the potential of BDDL as a high-energy electron source for use with co-catalysts in photochemical conversion.

  13. Comparison of electrocatalytic characterization of boron-doped diamond and SnO2 electrodes

    International Nuclear Information System (INIS)

    Lv, Jiangwei; Feng, Yujie; Liu, Junfeng; Qu, Youpeng; Cui, Fuyi

    2013-01-01

    Boron-doped diamond (BDD) and SnO 2 electrodes were prepared by direct current plasma chemical vapor deposition (DC-PCVD) and sol–gel method, respectively. Electrochemical characterization of the two electrodes were investigated by phenol electrochemical degradation, accelerated service life test, cyclic voltammetry (CV) in phenol solution, polarization curves in H 2 SO 4 . The surface morphology and crystal structure of two electrodes were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. The results showed a considerable difference between the two electrodes in their electrocatalytic activity, electrochemical stability and surface properties. Phenol was readily mineralized to CO 2 at BDD electrode, favoring electrochemical combustion, but its degradation was much slower at SnO 2 electrode. The service life of BDD electrode was 10 times longer than that of SnO 2 . Higher electrocatalytic activity and electrochemical stability of BDD electrode arise from its high oxygen evolution potential and the physically absorbed hydroxyl radicals (·OH) on electrode surface.

  14. Development of a biochemical oxygen demand sensor using gold-modified boron doped diamond electrodes.

    Science.gov (United States)

    Ivandini, Tribidasari A; Saepudin, Endang; Wardah, Habibah; Harmesa; Dewangga, Netra; Einaga, Yasuaki

    2012-11-20

    Gold-modified boron doped diamond (BDD) electrodes were examined for the amperometric detection of oxygen as well as a detector for measuring biochemical oxygen demand (BOD) using Rhodotorula mucilaginosa UICC Y-181. An optimum potential of -0.5 V (vs Ag/AgCl) was applied, and the optimum waiting time was observed to be 20 min. A linear calibration curve for oxygen reduction was achieved with a sensitivity of 1.4 μA mg(-1) L oxygen. Furthermore, a linear calibration curve in the glucose concentration range of 0.1-0.5 mM (equivalent to 10-50 mg L(-1) BOD) was obtained with an estimated detection limit of 4 mg L(-1) BOD. Excellent reproducibility of the BOD sensor was shown with an RSD of 0.9%. Moreover, the BOD sensor showed good tolerance against the presence of copper ions up to a maximum concentration of 0.80 μM (equivalent to 50 ppb). The sensor was applied to BOD measurements of the water from a lake at the University of Indonesia in Jakarta, Indonesia, with results comparable to those made using a standard method for BOD measurement.

  15. Yeast-based Biochemical Oxygen Demand Sensors Using Gold-modified Boron-doped Diamond Electrodes.

    Science.gov (United States)

    Ivandini, Tribidasari A; Harmesa; Saepudin, Endang; Einaga, Yasuaki

    2015-01-01

    A gold nanoparticle modified boron-doped diamond electrode was developed as a transducer for biochemical oxygen demand (BOD) measurements. Rhodotorula mucilaginosa UICC Y-181 was immobilized in a sodium alginate matrix, and used as a biosensing agent. Cyclic voltammetry was applied to study the oxygen reduction reaction at the electrode, while amperometry was employed to detect oxygen, which was not consumed by the microorganisms. The optimum waiting time of 25 min was observed using 1-mm thickness of yeast film. A comparison against the system with free yeast cells shows less sensitivity of the current responses with a linear dynamic range (R(2) = 0.99) of from 0.10 mM to 0.90 mM glucose (equivalent to 10 - 90 mg/L BOD) with an estimated limit of detection of 1.90 mg/L BOD. However, a better stability of the current responses could be achieved with an RSD of 3.35%. Moreover, less influence from the presence of copper ions was observed. The results indicate that the yeast-immobilized BOD sensors is more suitable to be applied in a real condition.

  16. Scanning tunneling microscopy and spectroscopy studies of superconducting boron-doped diamond films

    Directory of Open Access Journals (Sweden)

    Terukazu Nishizaki, Yoshihiko Takano, Masanori Nagao, Tomohiro Takenouchi, Hiroshi Kawarada and Norio Kobayashi

    2006-01-01

    Full Text Available We report on scanning tunneling microscopy/spectroscopy (STM/STS experiments on (1 1 1-oriented epitaxial films of heavily boron-doped diamond grown by using the microwave plasma-assisted chemical vapor deposition method. STM/STS measurements were performed by 3He-refrigerator based STM under ultra-high vacuum. The STM topography on the film surface shows a corrugation (with a typical size of ~1 μm and grain-like microstructures (~5–20 nm. The tunneling conductance spectra do not show large spatial dependence and superconductivity is observed independent of the surface structures. The tunneling spectra are analyzed by the Dynes function and the superconducting energy gap is estimated to be Δ=0.87 meV at T=0.47 K, corresponding to 2Δ/kBTc=3.7. The relatively large value of the broadening parameter Γ=0.38 meV is discussed in terms of the inelastic electron scattering processes.

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

    International Nuclear Information System (INIS)

    Martinez-Huitle, C.A.; Ferro, S.; Battisti, A. de; Reyna, S.; Cerro-Lopez, M.; Quiroz, M.A.

    2008-01-01

    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 - primarily acts in the volume of the solution, with the formation of strong oxidants; while Cl - 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. Voltammetric determination of caffeine in beverage samples on bare boron-doped diamond electrode.

    Science.gov (United States)

    Svorc, L'ubomír; Tomčík, Peter; Svítková, Jana; Rievaj, Miroslav; Bustin, Dušan

    2012-12-01

    A sensitive and selective electrochemical method for the caffeine determination using bare boron-doped diamond electrode was developed. It was found that caffeine provided highly reproducible and well-defined irreversible oxidation peak at very positive potential. The effects of supporting electrolyte, pH and scan rate on the voltammetric response of caffeine oxidation were studied to select the optimum experimental conditions. Linear response of peak current on the concentration in the range from 4×10(-7) to 2.5×10(-5)M, good repeatability (RSD of 2.1%) and detection limit of 1.5×10(-7)M without any chemical modifications and electrochemical surface pretreatment were evaluated. The effect of possible interferents appeared to be negligible which evidently proved very good selectivity. The proposed method was successfully applied for the caffeine determination in commercially available beverage samples, with results in a close statistical agreement to those declared by manufacturer and HPLC used as independent method. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Electrochemical detection of peroxynitrite using hemin-PEDOT functionalized boron-doped diamond microelectrode.

    Science.gov (United States)

    Peteu, Serban F; Whitman, Brandon W; Galligan, James J; Swain, Greg M

    2016-03-07

    Peroxynitrite is a potent nitroxidation agent and highly reactive metabolite, clinically correlated with a rich pathophysiology. Its sensitive and selective detection is challenging due to its high reactivity and short sub-second lifetime. Boron-doped diamond (BDD) microelectrodes have attracted interest because of their outstanding electroanalytical properties that include a wide working potential window and enhanced signal-to-noise ratio. Herein, we report on the modification of a BDD microelectrode with an electro-polymerized film of hemin and polyethylenedioxythiophene (PEDOT) for the purpose of selectively quantifying peroxynitrite. The nanostructured modified polymer layer was characterized by Raman spectroscopy and scanning electron microscopy (SEM). The electrochemical response to peroxynitrite was studied by voltammetry and time-based amperometry. The measured detection limit was 10 ± 0.5 nM (S/N = 3), the sensitivity was 4.5 ± 0.5 nA nM(-1) and the response time was 3.5 ± 1 s. The hemin-PEDOT BDD sensors exhibited a response variability of 5% or less (RSD). The stability of the sensors after a 20-day storage in 0.1 M PB (pH 7.4) at 4 °C was excellent as at least 93% of the initial response to 50 nM PON was maintained. The presence of PEDOT was correlated with a sensitivity increase.

  20. Fabrication of Nickel/nanodiamond/boron-doped diamond electrode for non-enzymatic glucose biosensor

    International Nuclear Information System (INIS)

    Dai, Wei; Li, Mingji; Gao, Sumei; Li, Hongji; Li, Cuiping; Xu, Sheng; Wu, Xiaoguo; Yang, Baohe

    2016-01-01

    Highlights: • Nanodiamonds (NDs) were electrophoretically deposited on the BDD film. • The NDs significantly extended the potential window. • Ni/NDs/BDD electrode was prepared by electrodeposition. • The electrode shows good catalytic activity for glucose oxidation. - Abstract: A stable and sensitive non-enzymatic glucose sensor was prepared by modifying a boron-doped diamond (BDD) electrode with nickel (Ni) nanosheets and nanodiamonds (NDs). The NDs were electrophoretically deposited on the BDD surface, and acted as nucleation sites for the subsequent electrodeposition of Ni. The morphology and composition of the modified BDD electrodes were characterized by field-emission scanning electron microscopy and energy-dispersive X-ray spectroscopy, respectively. The Ni nanosheet-ND modified BDD electrode exhibited good current response towards the non-enzymatic oxidation of glucose in alkaline media. The NDs significantly extended the potential window. The response to glucose was linear over the 0.2–1055.4-μM range. The limit of detection was 0.05 μM, at a signal-to-noise ratio of 3. The Ni nanosheet-ND/BDD electrode exhibited good selectivity, reproducibility and stability. Its electrochemical performance, low cost and simple preparation make it a promising non-enzymatic glucose sensor.

  1. Optical and electrical properties of boron doped diamond thin conductive films deposited on fused silica glass substrates

    Energy Technology Data Exchange (ETDEWEB)

    Ficek, M.; Sobaszek, M.; Gnyba, M. [Department of Metrology and Optoelectronics, Gdansk University of Technology, 11/12G. Narutowicza St., 80-233 Gdansk (Poland); Ryl, J. [Department of Electrochemistry, Corrosion and Material Engineering, Gdansk University of Technology, 11/12 Narutowicza St., 80-233 Gdansk (Poland); Gołuński, Ł. [Department of Metrology and Optoelectronics, Gdansk University of Technology, 11/12G. Narutowicza St., 80-233 Gdansk (Poland); Smietana, M.; Jasiński, J. [Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, 75 Koszykowa St., 00-662 Warsaw (Poland); Caban, P. [Institute of Electronic Materials Technology, 133 Wolczynska St., 01-919 Warsaw (Poland); Bogdanowicz, R., E-mail: rbogdan@eti.pg.gda.pl [Department of Metrology and Optoelectronics, Gdansk University of Technology, 11/12G. Narutowicza St., 80-233 Gdansk (Poland); Materials and Process Simulation Center, California Institute of Technology, Pasadena, CA 91125 (United States)

    2016-11-30

    Highlights: • Growth of 60% of transmittance diamond films with resistivity as low as 48 Ω cm. • Two step seeding process of fused silica: plasma hydrogenation and wet seeding. • Nanodiamond seeding density of 2 × 10{sup 10} cm{sup −2} at fused silica substrates. • High refractive index (2.4 @550 nm) was achieved for BDD films deposited at 500 °C. - Abstract: This paper presents boron-doped diamond (BDD) film as a conductive coating for optical and electronic purposes. Seeding and growth processes of thin diamond films on fused silica have been investigated. Growth processes of thin diamond films on fused silica were investigated at various boron doping level and methane admixture. Two step pre-treatment procedure of fused silica substrate was applied to achieve high seeding density. First, the substrates undergo the hydrogen plasma treatment then spin-coating seeding using a dispersion consisting of detonation nanodiamond in dimethyl sulfoxide with polyvinyl alcohol was applied. Such an approach results in seeding density of 2 × 10{sup 10} cm{sup −2}. The scanning electron microscopy images showed homogenous, continuous and polycrystalline surface morphology with minimal grain size of 200 nm for highly boron doped films. The sp{sup 3}/sp{sup 2} ratio was calculated using Raman spectra deconvolution method. A high refractive index (range of 2.0–2.4 @550 nm) was achieved for BDD films deposited at 500 °C. The values of extinction coefficient were below 0.1 at λ = 550 nm, indicating low absorption of the film. The fabricated BDD thin films displayed resistivity below 48 Ohm cm and transmittance over 60% in the visible wavelength range.

  2. Fabrication of boron-doped nanocrystalline diamond nanoflowers based on 3D Cu(OH){sub 2} dendritic architectures

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Huijun; Hong, Sukin; Lee, Seungkoo; Lim, Daesoon; Jin, Juneon; Hwang, Sungwoo [Korea University, Seoul (Korea, Republic of)

    2012-03-15

    Hot-filament chemical vapor deposition (HFCVD) was used to prepare boron-doped nanocrystalline diamond (BDND) nanoflowers on a Cu substrate with a Cu(OH){sub 2} dendritic architecture that had been formed by using electrostatic self-assembly (ESA) method with nanodiamond particles. The formation of diamond nanoflowers is controlled by the reaction time between the Cu(OH){sub 2} nanoflowers and the polymeric linker for the electrostatic attachment of nanodiamonds and by the deposition time for CVD diamond growth with a high nucleation density. Through analysis by field emission scanning electron microscopy (FESEM) and Raman spectroscopy, the optimal conditions for the synthesis of BDND nanoflowers are determined, and a possible explanation is provided.

  3. Fabrication of boron-doped nanocrystalline diamond nanoflowers based on 3D Cu(OH)2 dendritic architectures

    International Nuclear Information System (INIS)

    Sim, Huijun; Hong, Sukin; Lee, Seungkoo; Lim, Daesoon; Jin, Juneon; Hwang, Sungwoo

    2012-01-01

    Hot-filament chemical vapor deposition (HFCVD) was used to prepare boron-doped nanocrystalline diamond (BDND) nanoflowers on a Cu substrate with a Cu(OH) 2 dendritic architecture that had been formed by using electrostatic self-assembly (ESA) method with nanodiamond particles. The formation of diamond nanoflowers is controlled by the reaction time between the Cu(OH) 2 nanoflowers and the polymeric linker for the electrostatic attachment of nanodiamonds and by the deposition time for CVD diamond growth with a high nucleation density. Through analysis by field emission scanning electron microscopy (FESEM) and Raman spectroscopy, the optimal conditions for the synthesis of BDND nanoflowers are determined, and a possible explanation is provided.

  4. 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.

  5. 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

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

    Science.gov (United States)

    Zhang, Chunyong; Fu, Degang; Gu, Zhongze

    2009-12-30

    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 (c(NaCl)) and applied current density (I(appl)). Full and quick removal of 0.50 microg/ml MC-RR in solution was achieved when the operating conditions of c(NaCl) and I(appl) were 20mM and 46.3 mA/cm(2), or 35 mM and 18.2 mA/cm(2) 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.

  7. Boron-doped diamond electrodes for the electrochemical oxidation and cleavage of peptides.

    Science.gov (United States)

    Roeser, Julien; Alting, Niels F A; Permentier, Hjalmar P; Bruins, Andries P; Bischoff, Rainer

    2013-07-16

    Electrochemical oxidation of peptides and proteins is traditionally performed on carbon-based electrodes. Adsorption caused by the affinity of hydrophobic and aromatic amino acids toward these surfaces leads to electrode fouling. We compared the performance of boron-doped diamond (BDD) and glassy carbon (GC) electrodes for the electrochemical oxidation and cleavage of peptides. An optimal working potential of 2000 mV was chosen to ensure oxidation of peptides on BDD by electron transfer processes only. Oxidation by electrogenerated OH radicals took place above 2500 mV on BDD, which is undesirable if cleavage of a peptide is to be achieved. BDD showed improved cleavage yield and reduced adsorption for a set of small peptides, some of which had been previously shown to undergo electrochemical cleavage C-terminal to tyrosine (Tyr) and tryptophan (Trp) on porous carbon electrodes. Repeated oxidation with BDD electrodes resulted in progressively lower conversion yields due to a change in surface termination. Cathodic pretreatment of BDD at a negative potential in an acidic environment successfully regenerated the electrode surface and allowed for repeatable reactions over extended periods of time. BDD electrodes are a promising alternative to GC electrodes in terms of reduced adsorption and fouling and the possibility to regenerate them for consistent high-yield electrochemical cleavage of peptides. The fact that OH-radicals can be produced by anodic oxidation of water at elevated positive potentials is an additional advantage as they allow another set of oxidative reactions in analogy to the Fenton reaction, thus widening the scope of electrochemistry in protein and peptide chemistry and analytics.

  8. Fabrication of porous boron-doped diamond electrodes by catalytic etching under hydrogen-argon plasma

    Science.gov (United States)

    Shi, Chao; Li, Cuiping; Li, Mingji; Li, Hongji; Dai, Wei; Wu, Yongheng; Yang, Baohe

    2016-01-01

    Porous boron-doped diamond (BDD) was prepared by hydrogen-argon plasma etching using electrodeposited Ni nanoparticles as a catalyst. The etching process and formation mechanism of porous BDD were investigated by changing the etching time from 30 s to 300 s. Pores were produced due to the C atoms around Ni nanoparticles are easy to react with hydrogen plasma and form methane. With the increase of etching time, the pore size increased, the pore density decreased, and the pore depth first increased and then maintained unchanged. The sp2-bonded graphitic carbons existing on the surface of BDD increase with increasing etching time due to the increase of surface area. No preferential etching was observed due to the high energy of argon plasma. The electrochemical behaviors of the pristine and porous BDD electrodes were characterized by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS). The results showed that the porous BDD electrode exhibited high specific capacitance, which is attributed to its high electrical conductivity and large specific surface area. The highest specific capacitance of porous BDD electrode is 9.55 mF cm-2, which is 22 times higher than that of pristine BDD electrode. The specific capacitance retention of the porous BDD electrode reduced to 98.2% of the initial capacitance after 500 cycles and then increased to 120.0% after 10,000 cycles. For the first 500 cycles, the reduction of capacitance can be attributed to the dissolution of Ni nanoparticles that attached on the porous BDD surface or buried in the shallow layer. The capacitance increase after 10,000 cycles is due to the better contact of the electrolytic solution with the residual Ni with the increase of cycle number.

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

    Science.gov (United States)

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

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

  10. Anodic stripping voltammetry of synthesized CdS nanoparticles at boron-doped diamond electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Hayat, Mohammad; Ivandini, Tribidasari A., E-mail: ivandini.tri@sci.ui.ac.id; Saepudin, Endang [Department of Chemistry, FMIPA, Universitas Indonesia, Kampus UI Depok (Indonesia); Einaga, Yasuaki [Department of Chemistry, Keio University (Japan)

    2016-04-19

    Cadmium sulphide (CdS) nanoparticles were chemically synthesized using reverse micelles microreactor methods. By using different washing treatments, UV-Vis spectroscopy showed that the absorption peaks appeared at 465 nm, 462 nm, 460 nm, and 459 nm respectively for CdS nanoparticles without and with 1, 2, and 3 times washing treatments using pure water. In comparison with the absorbance peak of bulk CdS at 512 nm, the shifted absorption peaks, indicates that the different sizes of CdS can be prepared. Anodic stripping voltammetry of the CdS nanoparticles was then studied at a boron-doped diamond electrode using 0.1 M KClO{sub 4} and 0.1 M HClO{sub 4} as the electrolytes. A scan rate of 100 mV/s with a deposition potential of -1000 mV (vs. Ag/AgCl) for 60 s at a potential scan from -1600 mV to +800 mV (vs. Ag/AgCl) was applied as the optimum condition of the measurements. Highly-accurate linear calibration curves (R{sup 2} = 0.99) in 0.1 M HClO{sub 4} with the sensitivity of 0.075 mA/mM and the limit of detection of 81 µM in 0.1 M HClO{sub 4} can be achieved, which is promising for an application of CdS nanoparticles as a label for biosensors.

  11. Electrochemical oxidation and electroanalytical determination of xylitol at a boron-doped diamond electrode.

    Science.gov (United States)

    Lourenço, Anabel S; Sanches, Fátima A C; Magalhães, Renata R; Costa, Daniel J E; Ribeiro, Williame F; Bichinho, Kátia M; Salazar-Banda, Giancarlo R; Araújo, Mário C U

    2014-02-01

    Xylitol is a reduced sugar with anticariogenic properties used by insulin-dependent diabetics, and which has attracted great attention of the pharmaceutical, cosmetics, food and dental industries. The detection of xylitol in different matrices is generally based on separation techniques. Alternatively, in this paper, the application of a boron-doped diamond (BDD) electrode allied to differing voltammetric techniques is presented to study the electrochemical behavior of xylitol, and to develop an analytical methodology for its determination in mouthwash. Xylitol undergoes two oxidation steps in an irreversible diffusion-controlled process (D=5.05 × 10(-5)cm(2)s(-1)). Differential pulse voltammetry studies revealed that the oxidation mechanism for peaks P1 (3.4 ≤ pH ≤ 8.0), and P2 (6.0 ≤ pH ≤ 9.0) involves transfer of 1H(+)/1e(-), and 1e(-) alone, respectively. The oxidation process P1 is mediated by the (•)OH generated at the BDD hydrogen-terminated surface. The maximum peak current was obtained at a pH of 7.0, and the electroanalytical method developed, (employing square wave voltammetry) yielded low detection (1.3 × 10(-6) mol L(-1)), and quantification (4.5 × 10(-6) mol L(-1)) limits, associated with good levels of repeatability (4.7%), and reproducibility (5.3%); thus demonstrating the viability of the methodology for detection of xylitol in biological samples containing low concentrations. © 2013 Elsevier B.V. All rights reserved.

  12. 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 - others: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

  13. Anodic oxidation of wastewater containing the Reactive Orange 16 Dye using heavily boron-doped diamond electrodes

    International Nuclear Information System (INIS)

    Migliorini, F.L.; Braga, N.A.; Alves, S.A.; Lanza, M.R.V.; Baldan, M.R.; Ferreira, N.G.

    2011-01-01

    Highlights: → Electrochemical advanced oxidation process was studied using BDD based anodes with different boron concentrations. → The difference between the non-active and active anodes for organics degradation. → The influence of morphologic and structural properties of BDD electrodes on the RO-16 dye degradation. - Abstract: Boron-doped diamond (BDD) films grown on the titanium substrate were used to study the electrochemical degradation of Reactive Orange (RO) 16 Dye. The films were produced by hot filament chemical vapor deposition (HFCVD) technique using two different boron concentrations. The growth parameters were controlled to obtain heavily doped diamond films. They were named as E1 and E2 electrodes, with acceptor concentrations of 4.0 and 8.0 x 10 21 atoms cm -3 , respectively. The boron levels were evaluated from Mott-Schottky plots also corroborated by Raman's spectra, which characterized the film quality as well as its physical property. Scanning Electron Microscopy showed well-defined microcrystalline grain morphologies with crystal orientation mixtures of (1 1 1) and (1 0 0). The electrode efficiencies were studied from the advanced oxidation process (AOP) to degrade electrochemically the Reactive Orange 16 azo-dye (RO16). The results were analyzed by UV/VIS spectroscopy, total organic carbon (TOC) and high-performance liquid chromatography (HPLC) techniques. From UV/VIS spectra the highest doped electrode (E2) showed the best efficiency for both, the aromaticity reduction and the azo group fracture. These tendencies were confirmed by the TOC and chromatographic measurements. Besides, the results showed a direct relationship among the BDD morphology, physical property, and its performance during the degradation process.

  14. 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.

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

    Czech Academy of Sciences Publication Activity Database

    Krýsová, Hana; Bartoň, Jan; Petrák, Václav; Jurok, R.; Kuchař, M.; Cígler, Petr; Kavan, Ladislav

    2016-01-01

    Roč. 18, č. 24 (2016), s. 16444-16450 ISSN 1463-9076 R&D Projects: GA ČR GA13-31783S Institutional support: RVO:61388955 ; RVO:61388963 ; RVO:68378271 Keywords : dye-sensitized solar cells * boron-doped diamond * nanoscale Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.123, year: 2016

  16. 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.

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

    CERN Document Server

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

    2002-01-01

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

  18. Destination of organic pollutants during electrochemical oxidation of biologically-pretreated dye wastewater using boron-doped diamond anode

    International Nuclear Information System (INIS)

    Zhu, Xiuping; Ni, Jinren; Wei, Junjun; Xing, Xuan; Li, Hongna

    2011-01-01

    Electrochemical oxidation of biologically-pretreated dye wastewater was performed in a boron-doped diamond (BDD) anode system. After electrolysis of 12 h, the COD was decreased from 532 to 99 mg L -1 ( -1 , the National Discharge Standard of China). More importantly, the destination of organic pollutants during electrochemical oxidation process was carefully investigated by molecular weight distribution measurement, resin fractionation, ultraviolet-visible spectroscopy, HPLC and GC-MS analysis, and toxicity test. As results, most organic pollutants were completely removed by electrochemical oxidation and the rest was primarily degraded to simpler compounds (e.g., carboxylic acids and short-chain alkanes) with less toxicity, which demonstrated that electrochemical oxidation of biologically-pretreated dye wastewater with BDD anode was very effective and safe. Especially, the performance of BDD anode system in degradation of large molecular organics such as humic substances makes it very promising in practical applications as an advanced treatment of biologically-pretreated wastewaters.

  19. Detection of trace levels of Pb2+ in tap water at boron-doped diamond electrodes with anodic stripping voltammetry

    International Nuclear Information System (INIS)

    Dragoe, Diana; Spataru, Nicolae; Kawasaki, Ryuji; Manivannan, Ayyakkannu; Spataru, Tanta; Tryk, Donald A.; Fujishima, Akira

    2006-01-01

    Boron-doped diamond (BDD) electrodes were used to investigate the possibility of detecting trace levels of lead by linear-sweep anodic stripping voltammetry. The low limit of detection (2 nM) is an advantage compared to other electrode materials, and it was found that at low pH values, copper concentrations that are usually present in drinking water do not affect to a large extent the detection of lead. These findings recommend anodic stripping voltammetry at the BDD electrodes as a suitable mercury-free method for the determination of trace levels of lead in drinking water. The results obtained for the lead detection in tap water real samples are in excellent agreement with those found by inductively coupled plasma-mass spectrometry (ICP-MS), demonstrating the practical analytical utility of the method

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

    International Nuclear Information System (INIS)

    Aquino, Jose M.; Pereira, Gabriel F.; Rocha-Filho, Romeu C.; Bocchi, Nerilso; Biaggio, Sonia R.

    2011-01-01

    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. · PbO 2 anode, due to low cost and easiness of preparation, may be an option to decolorize the effluents. - Abstract: Constant current electrolyses are carried out in a filter-press reactor using a boron-doped diamond (Nb/BDD) or a Ti-Pt/β-PbO 2 anode, varying current density (j) and temperature. The degradation of the real textile effluent is followed by its decolorization and chemical oxygen demand (COD) abatement. The effect of adding NaCl (1.5 g L -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-PbO 2 anode, at any experimental condition. The best conditions are j = 5 mA cm -2 and 55 o C, for the system's optimized hydrodynamic conditions. The addition of chloride ions significantly increases the decolorization rate; thus a decrease of more than 90% of the effluent relative absorbance is attained using an applied electric charge per unit volume of the electrolyzed effluent (Q ap ) of only about 2 kA h m -3 . Practically total abatement of the effluent COD is attained with the Nb/BDD anode using a Q ap 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.

  1. Occurrence of pharmaceuticals, illicit drugs, and resistant types of bacteria in hospital effluent and their effective degradation by boron-doped diamond electrodes

    Czech Academy of Sciences Publication Activity Database

    Mackuľak, T.; Vojs, M.; Grabic, R.; Golovko, O.; Staňová, A.; Birošová, L.; Medveďová, A.; Híveš, J.; Gál, M.; Kromka, Alexander; Hanusová, A.

    2016-01-01

    Roč. 147, č. 1 (2016), s. 93-103 ISSN 0026-9247. [35th International Conference on Modern Electrochemical Methods (MEM). Jetřichovice, 18.05.2015-22.05.2015] Institutional support: RVO:68378271 Keywords : hospital wastewater * antibiotics * ecology * boron-doped diamond electrode * mass spectroscopy * pharmaceuticals Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.282, year: 2016

  2. 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

  3. Simultaneous voltammetric determination of paracetamol and ascorbic acid using a boron-doped diamond electrode modified with Nafion and lead films.

    Science.gov (United States)

    Tyszczuk-Rotko, Katarzyna; Bęczkowska, Ilona; Wójciak-Kosior, Magdalena; Sowa, Ireneusz

    2014-11-01

    The paper describes the fabrication and application of a novel sensor (a boron-doped diamond electrode modified with Nafion and lead films) for the simultaneous determination of paracetamol and ascorbic acid by differential pulse voltammetry. The main advantage of the lead film and polymer covered boron-doped diamond electrode is that the sensitivity of the stripping responses is increased and the separation of paracetamol and ascorbic acid signals is improved due to the modification of the boron-doped diamond surface by the lead layer. Additionally, the repeatability of paracetamol and ascorbic acid signals is improved by the application of the Nafion film coating. In the presence of oxygen, linear calibration curves were obtained in a wide concentration range from 5×10(-7) to 2×10(-4) mol L(-1) for paracetamol and from 1×10(-6) to 5×10(-4) mol L(-1) for ascorbic acid. The analytical utility of the differential pulse voltammetric method elaborated was tested in the assay of paracetamol and ascorbic acid in commercially available pharmaceutical formulations and the method was validated by high performance liquid chromatography coupled with diode array detector. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Boron-doped CVD diamond films. Part I. History, production and characterization; Filmes de diamante CVD dopado com boro. Parte I . Historico, producao e caracterizacao

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Rita de Cassia Mendes de; Ribeiro, Mauro Celso; An-Sumodjo, Paulo Teng; Juliao, Murilo Sergio da Silva; Serrano, Silvia Helena Pires [Sao Paulo Univ., SP (Brazil). Inst. de Quimica]. E-mail: shps@iq.usp.br; Ferreira, Neidenei Gomes [Centro Tecnico Aeroespacial, Sao Jose dos Campos, SP (Brazil). Div. de Materiais

    2005-04-01

    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. (author)

  5. Improvement on p-type CVD diamond semiconducting properties by fabricating thin heavily-boron-doped multi-layer clusters isolated each other in unintentionally boron-doped diamond layer

    Science.gov (United States)

    Maida, Osamu; Tabuchi, Tomohiro; Ito, Toshimichi

    2017-12-01

    We have developed a new fabrication process to decrease the effective activation energy of B atoms doped in diamond without a significant decrease in the carrier mobility by fabricating heavily B-doped clusters with very low mobility which are embedded in lightly-B-doped diamond layers. The resistivities of the heavily B-doped and unintentionally B-doped diamond stacked layers had almost no temperature dependence, suggesting the presence of an impurity-band conduction in these diamond layers. On the other hand, the resistivities of the samples after the embedding growth process of the stacked layers that had been appropriately divided to innumerable small clusters by means of a suitable etching process increased with decreasing the temperature from 330 to 130 K. The effective activation energies and Hall mobilities at room temperature of both samples were estimated to be 0.21 eV, 106 cm2 V-1 s-1 for micron-sized clusters and 0.23 eV, 470 cm2 V-1 s-1 for nano-sized clusters, respectively, indicating that the diamond film structure fabricated in this work is effective for the improvement of the p-type performance for the B-doped CVD diamond.

  6. Electronic structures of B 2p and C 2p levels in boron-doped diamond films studied using soft x-ray absorption and emission spectroscopy

    Science.gov (United States)

    Nakamura, Jin; Kabasawa, Eiki; Yamada, Nobuyoshi; Einaga, Yasuaki; Saito, Daisuke; Isshiki, Hideo; Yugo, Shigemi; Perera, Rupert C. C.

    2004-12-01

    X-ray absorption (XAS) and emission (XES) spectroscopy near B K and C K edges have been performed on metallic ( ˜0.1at.% B, B-diamond) and semiconducting ( ˜0.03at.% B and N, BN-diamond) doped diamond films. Both B K XAS and XES spectra show a metallic partial density of states (PDOS) with the Fermi energy of 185.3eV , and there is no apparent boron-concentration dependence in contrast to the different electric property. In C K XAS spectrum of B-diamond, the impurity state ascribed to boron is clearly observed near the Fermi level. The Fermi energy is found to be almost same with the top of the valence band of nondoped diamond: EV=283.9eV . C K XAS of BN-diamond shows both the B-induced shallow level and N-induced deep and broad levels as the in-gap states, in which the shallow level is in good agreement with the activation energy (Ea=0.37eV) estimated from the temperature dependence of the conductivity; namely, the change in C2p PDOS of impurity-induced metallization is directly observed. The electric property of this diamond is ascribed mainly to the electronic structure of C2p near the Fermi level. The observed XES spectra are compared with the discrete variational Xα ( DVXα ) cluster calculation. The DVXα result supports the strong hybridization between B2p and C2p observed in XAS and XES spectra, and suggests that the small amount of boron (⩽0.1at.%) in diamond occupies the substitutional site rather than interstitial site.

  7. Effect of boron doping on the wear behavior of the growth and nucleation surfaces of micro- and nanocrystalline diamond films

    NARCIS (Netherlands)

    Buijnsters, J.G.; Tsigkourakos, M.C.; Hantschel, T.; Gomes, F.O.V.; Nuytten, T.; Favia, P.; Bender, H; Arstila, K.; Celis, JP; Vandervorst, W

    2016-01-01

    B-doped diamond has become the ultimate material for applications in the field of microelectromechanical systems (MEMS), which require both highly wear resistant and electrically conductive diamond films and microstructures. Despite the extensive research of the tribological properties of undoped

  8. Self-organized multi-layered graphene-boron-doped diamond hybrid nanowalls for high-performance electron emission devices.

    Science.gov (United States)

    Sankaran, Kamatchi Jothiramalingam; Ficek, Mateusz; Kunuku, Srinivasu; Panda, Kalpataru; Yeh, Chien-Jui; Park, Jeong Young; Sawczak, Miroslaw; Michałowski, Paweł Piotr; Leou, Keh-Chyang; Bogdanowicz, Robert; Lin, I-Nan; Haenen, Ken

    2018-01-18

    Carbon nanomaterials such as nanotubes, nanoflakes/nanowalls, and graphene have been used as electron sources due to their superior field electron emission (FEE) characteristics. However, these materials show poor stability and short lifetimes, which prevent their use in practical device applications. The aim of this study was to find an innovative nanomaterial possessing both high robustness and reliable FEE behavior. Herein, a hybrid structure of self-organized multi-layered graphene (MLG)-boron doped diamond (BDD) nanowall materials with superior FEE characteristics was successfully synthesized using a microwave plasma enhanced chemical vapor deposition process. Transmission electron microscopy reveals that the as-prepared carbon clusters have a uniform, dense, and sharp nanowall morphology with sp 3 diamond cores encased by an sp 2 MLG shell. Detailed nanoscale investigations conducted using peak force-controlled tunneling atomic force microscopy show that each of the core-shell structured carbon cluster fields emits electrons equally well. The MLG-BDD nanowall materials show a low turn-on field of 2.4 V μm -1 , a high emission current density of 4.2 mA cm -2 at an applied field of 4.0 V μm -1 , a large field enhancement factor of 4500, and prominently high lifetime stability (lasting for 700 min), which demonstrate the superiority of these materials over other hybrid nanostructured materials. The potential of these MLG-BDD hybrid nanowall materials in practical device applications was further illustrated by the plasma illumination behavior of a microplasma device with these materials as the cathode, where a low threshold voltage of 330 V (low threshold field of 330 V mm -1 ) and long plasma stability of 358 min were demonstrated. The fabrication of these hybrid nanowalls is straight forward and thereby opens up a pathway for the advancement of next-generation cathode materials for high brightness electron emission and microplasma-based display devices.

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

    Science.gov (United States)

    Aquino, José M; Pereira, Gabriel F; Rocha-Filho, Romeu C; Bocchi, Nerilso; Biaggio, Sonia R

    2011-09-15

    Constant current electrolyses are carried out in a filter-press reactor using a boron-doped diamond (Nb/BDD) or a Ti-Pt/β-PbO(2) anode, varying current density (j) and temperature. The degradation of the real textile effluent is followed by its decolorization and chemical oxygen demand (COD) abatement. The effect of adding NaCl (1.5 g L(-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-PbO(2) anode, at any experimental condition. The best conditions are j = 5 mA cm(-2) and 55 °C, for the system's optimized hydrodynamic conditions. The addition of chloride ions significantly increases the decolorization rate; thus a decrease of more than 90% of the effluent relative absorbance is attained using an applied electric charge per unit volume of the electrolyzed effluent (Q(ap)) of only about 2 kA h m(-3). Practically total abatement of the effluent COD is attained with the Nb/BDD anode using a Q(ap) 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. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2016-12-05

    In this work the electrochemical oxidation of losartan, an emerging pharmaceutical pollutant, was studied. Electrochemical oxidation was carried out in batch mode, in an open and undivided cell of 100cm(3) using a boron-doped diamond (BDD)/stainless steel system. With Cl(-) medium 56% of mineralization was registered, while with the trials containing SO4(2-) as supporting electrolyte a higher mineralization yield of 67% was reached, even obtaining a total removal of losartan potassium at 80mAcm(-2) and 180min of reaction time at pH 7.0. Higher losartan potassium concentrations enhanced the mineralization degree and the efficiency of the electrochemical oxidation process. During the mineralization up to 4 aromatic intermediates were identified by ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Moreover, short-linear carboxylic acids, like oxalic, succinic and oxamic were detected and quantified by ion-exclusion HPLC. Finally, the ability of the electrochemical oxidation process to mineralize dissolved commercial tablets containing losartan was achieved, obtaining TOC removal up to 71% under optimized conditions (10mAcm(-2), 0.05M Na2SO4, pH 7.0 and 25°C and 360min of electrolysis). Copyright © 2016 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    Garcia-Segura, Sergi; Keller, Jürg; Brillas, Enric; Radjenovic, Jelena

    2015-01-01

    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. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. 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.

  14. Anodic stripping voltammetry of gold nanoparticles at boron-doped diamond electrodes and its application in immunochromatographic strip tests.

    Science.gov (United States)

    Ivandini, Tribidasari A; Wicaksono, Wiyogo P; Saepudin, Endang; Rismetov, Bakhadir; Einaga, Yasuaki

    2015-03-01

    Anodic stripping voltammetry (ASV) of colloidal gold-nanoparticles (AuNPs) was investigated at boron-doped diamond (BDD) electrodes in 50 mM HClO4. A deposition time of 300 s at-0.2 V (vs. Ag/AgCl) was fixed as the condition for the ASV. The voltammograms showed oxidation peaks that could be attributed to the oxidation of gold. These oxidation peaks were then investigated for potential application in immunochromatographic strip tests for the selective and quantitative detection of melamine, in which AuNPs were used as the label for the antibody of melamine. Linear regression of the oxidation peak currents appeared in the concentration range from 0.05-0.6 μg/mL melamine standard, with an estimated LOD of 0.069 μg/mL and an average relative standard deviation of 8.0%. This indicated that the method could be considered as an alternative method for selective and quantitative immunochromatographic applications. The validity was examined by the measurements of melamine injected into milk samples, which showed good recovery percentages during the measurements. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Experimental approach to controllably vary protein oxidation while minimizing electrode adsorption for boron-doped diamond electrochemical surface mapping applications.

    Science.gov (United States)

    McClintock, Carlee S; Hettich, Robert L

    2013-01-02

    Oxidative protein surface mapping has become a powerful approach for measuring the solvent accessibility of folded protein structures. A variety of techniques exist for generating the key reagent (i.e., hydroxyl radicals) for these measurements; however, these approaches range significantly in their complexity and expense of operation. This research expands upon earlier work to enhance the controllability of boron-doped diamond (BDD) electrochemistry as an easily accessible tool for producing hydroxyl radicals in order to oxidize a range of intact proteins. Efforts to modulate the oxidation level while minimizing the adsorption of protein to the electrode involved the use of relatively high flow rates to reduce protein residence time inside the electrochemical flow chamber. Additionally, a different cell activation approach using variable voltage to supply a controlled current allowed us to precisely tune the extent of oxidation in a protein-dependent manner. In order to gain perspective on the level of protein adsorption onto the electrode surface, studies were conducted to monitor protein concentration during electrolysis and gauge changes in the electrode surface between cell activation events. This report demonstrates the successful use of BDD electrochemistry for greater precision in generating a target number of oxidation events upon intact proteins.

  16. Electrochemical oxidation of tramadol in low-salinity reverse osmosis concentrates using boron-doped diamond anodes.

    Science.gov (United States)

    Lütke Eversloh, Christian; Schulz, Manoj; Wagner, Manfred; Ternes, Thomas A

    2015-04-01

    The electrochemical treatment of low-salinity reverse osmosis (RO) concentrates was investigated using tramadol (100 μM) as a model substance for persistent organic contaminants. Galvanostatic degradation experiments using boron-doped diamond electrodes at different applied currents were conducted in RO concentrates as well as in ultra-pure water containing either sodium chloride or sodium sulfate. Kinetic investigations revealed a significant influence of in-situ generated active chlorine besides direct anodic oxidation. Therefore, tramadol concentrations decreased more rapidly at elevated chloride content. Nevertheless, reduction of total organic carbon (TOC) was found to be comparatively low, demonstrating that transformation rather than mineralization was taking place. Early stage product formation could be attributed to both direct and indirect processes, including demethylation, hydroxylation, dehydration, oxidative aromatic ring cleavage and halogenation reactions. The latter led to various halogenated derivatives and resulted in AOX (adsorbable organic halogens) formation in the lower mg/L-range depending on the treatment conditions. Characterisation of transformation products (TPs) was achieved via MS(n) experiments and additional NMR measurements. Based on identification and quantification of the main TPs in different matrices and on additional potentiostatic electrolysis, a transformation pathway was proposed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. The Use of Boron-doped Diamond Electrode on Yeast-based Microbial Fuel Cell for Electricity Production

    Science.gov (United States)

    Hanzhola, G.; Tribidasari, A. I.; Endang, S.

    2018-01-01

    The dependency of fossil energy in Indonesia caused the crude oil production to be drastically decreased since 2001, while energy consumption increased. In addition, The use of fossil energy can cause several environmental problems. Therefore, we need an alternative environment-friendly energy as solution for these problems. A microbial fuel cell is one of the prospective alternative source of an environment-friendly energy source to be developed. In this study, Boron-doped diamond electrode was used as working electrode and Candida fukuyamaensis as biocatalyst in microbial fuel cell. Different pH of anode compartment (pH 6.5-7.5) and mediator concentration (10-100 μM) was used to produce an optimal electricity. MFC was operated for 3 hours. During operation, the current and voltage density was measured with potensiostat. The maximum power and current density are 425,82 mW/m2 and 440 mA/m2, respectively, for MFC using pH 7.5 at anode compartment without addition of methylene blue. The addition of redox mediator is lowering the produced electricity because of its anti microbial properties that can kill the microbe.

  18. 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)

  19. Enhanced selectivity of boron doped diamond electrodes for the detection of dopamine and ascorbic acid by increasing the film thickness

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Yao; Long, Hangyu [School of Material Science and Engineering, Central South University, Changsha 410083 (China); Ma, Li, E-mail: marycsupm@csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Wei, Quiping, E-mail: qiupwei@csu.edu.cn [School of Material Science and Engineering, Central South University, Changsha 410083 (China); State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Li, Site [School of Material Science and Engineering, Central South University, Changsha 410083 (China); Yu, Zhiming [School of Material Science and Engineering, Central South University, Changsha 410083 (China); State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Hu, Jingyuan [School of Material Science and Engineering, Central South University, Changsha 410083 (China); Liu, Peizhi [Key laboratory of interface science and engineering in advanced materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024,PR China (China); Wang, Yijia [School of Material Science and Engineering, Central South University, Changsha 410083 (China); Meng, Lingcong [Department of Chemistry, University of Warwick, Coventry, West Midlands CV4 7AL (United Kingdom)

    2016-12-30

    Highlights: • BDD electrodes with different thickness have been fabricated. • BDD electrodes are used for simultaneous detection of DA and AA. • Anodic pretreatment enhance the separation of DA and AA oxidation peak potential. • Thicker BDD electrode show better performance for DA detection coexisting with AA. - Abstract: In this paper, boron doped diamond (BDD) with different thickness were prepared by hot filament chemical vapor deposition. The performance of BDD electrodes for detecting dopamine (DA) and ascorbic acid (AA) were investigated. Scanning electron microscopy and Raman spectra reveal the grain size increases and the film quality improves with the increase of film thickness. Electrochemical test show that the transfer coefficient in [Fe{sub 3} (CN) {sub 6}]{sup 3−/4−} redox system increases with the increase of the film thickness. The results of selectivity and sensitivity for DA mixed with AA detection show that 8h-BDD and 12h-BDD electrodes possess well selective separated oxidation peaks of DA and AA, and the 12h-BDD electrode exhibits optimal sensitivity until the DA concentration drops to 1 μ M.

  20. Voltammetric determination of mixtures of caffeine and chlorogenic acid in beverage samples using a boron-doped diamond electrode.

    Science.gov (United States)

    Yardım, Yavuz; Keskin, Ertugrul; Şentürk, Zühre

    2013-11-15

    Herein, a boron-doped diamond (BDD) electrode that is anodically pretreated was used for the simultaneous determination of caffeine (CAF) and chlorogenic acid (CGA) by cyclic and adsorptive stripping voltammetry. The dependence of peak current and potential on pH, scan rate, accumulation parameters and other experimental variables were studied. By using square-wave stripping mode after 60 s accumulation under open-circuit voltage, the BDD electrode was able to separate the oxidation peak potentials of CAF and CGA present in binary mixtures by about 0.4V in Britton-Robinson buffer at pH 1.0. The limits of detection were 0.107 µg mL(-1) (5.51×10(-7) M) for CAF, and 0.448 µg mL(-1) (1.26×10(-6) M) for CGA. The practical applicability of this methodology was tested in commercially available beverage samples. © 2013 Elsevier B.V. All rights reserved.

  1. Simultaneous voltammetric determination of paracetamol and caffeine in pharmaceutical formulations using a boron-doped diamond electrode.

    Science.gov (United States)

    Lourenção, Bruna Cláudia; Medeiros, Roberta Antigo; Rocha-Filho, Romeu C; Mazo, Luiz Henrique; Fatibello-Filho, Orlando

    2009-05-15

    A simple and highly selective electrochemical method was developed for the single or simultaneous determination of paracetamol (N-acetyl-p-aminophenol, acetaminophen) and caffeine (3,7-dihydro-1,3,7-trimethyl-1H-purine-2,6-dione) in aqueous media (acetate buffer, pH 4.5) on a boron-doped diamond (BDD) electrode using square wave voltammetry (SWV) or differential pulse voltammetry (DPV). Using DPV with the cathodically pre-treated BDD electrode, a separation of about 550 mV between the peak oxidation potentials of paracetamol and caffeine present in binary mixtures was obtained. The calibration curves for the simultaneous determination of paracetamol and caffeine showed an excellent linear response, ranging from 5.0 x 10(-7)mol L(-1) to 8.3 x 10(-5)mol L(-1) for both compounds. The detection limits for the simultaneous determination of paracetamol and caffeine were 4.9 x 10(-7)mol L(-1) and 3.5 x 10(-8)mol L(-1), respectively. The proposed method was successfully applied in the simultaneous determination of paracetamol and caffeine in several pharmaceutical formulations (tablets), with results similar to those obtained using a high-performance liquid chromatography method (at 95% confidence level).

  2. 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)

  3. Electrochemical incineration of chloromethylphenoxy herbicides in acid medium by anodic oxidation with boron-doped diamond electrode

    International Nuclear Information System (INIS)

    Boye, Birame; Brillas, Enric; Marselli, Beatrice; Michaud, Pierre-Alain; Comninellis, Christos; Farnia, Giuseppe; Sandona, Giancarlo

    2006-01-01

    The electrochemical degradation of saturated solutions of herbicides 4-chloro-2-methylphenoxyacetic acid, 2-(4-chlorophenoxy)-2-methylpropionic acid and 2-(4-chloro-2-methylphenoxy)propionic acid in 1 M HClO 4 on a boron-doped diamond (BDD) thin film anode has been studied by chronoamperometry, cyclic voltammetry and bulk electrolysis. At low anodic potentials polymeric products are formed causing the fouling and deactivation of BDD. This is reactivated at high potentials when water decomposes producing hydroxyl radical as strong oxidant of organics. Electrolyses in a batch recirculation system at constant current density ≥8 mA cm -2 yielded overall decontamination of all saturated solution. The effect of current density and herbicide concentration on the degradation rate of each compound, the specific charge required for its total mineralization and instantaneous current efficiency have been investigated. Experimental results have been compared with those predicted by a theoretical model based on a fast anodic oxidation of initial herbicides, showing that at 30 mA cm -2 their degradation processes are completely controlled by mass transfer. Kinetic analysis of the change of herbicide concentration with time during electrolysis, determined by high-performance liquid chromatography, revealed that all compounds follow a pseudo first-order reaction. Aromatic intermediates and generated carboxylic acids have been identified using this technique and a general pathway for the electrochemical incineration of all herbicides on BDD is proposed

  4. Secondary electron emission from boron-doped diamond under ion impact: Applications in single-ion detection

    International Nuclear Information System (INIS)

    Kamiya, T.; Cholewa, M.; Saint, A.; Prawer, S.; Legge, G.J.; Butler, J.E.; Vestyck, D.J. , Jr.

    1997-01-01

    The secondary electron emission from a 2 μm thick boron-doped diamond film under ion (4.6 endash 7.7 MeV He + )impact is reported. The yield under ions impact is found to be remarkably high, stable over a period of many months, and independent of which side of the film (i.e., growth or substrate side) is exposed to the ion flux. By taking advantage of the high secondary-electron yield, the passage of each ion through the film could be detected with an efficiency of close to 100%, which to the best of our knowledge is the highest efficiency recorded to date for any thin-film window. This finding has an immediate application in single-ion irradiation systems where a thin vacuum window is required to allow extraction of an ion beam from the vacuum into air and at the same time offer 100% efficiency for the detection of the passage of the ion through the window. copyright 1997 American Institute of Physics

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

    International Nuclear Information System (INIS)

    Wu Meifen; Zhao Guohua; Li Mingfang; Liu Lei; Li Dongming

    2009-01-01

    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

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

    International Nuclear Information System (INIS)

    Lima, Amanda B.; Guimaraes, Carlos F.R.C.; Verly, Rodrigo M.; Silva, Leonardo M. da; Torres, Livia M.F.C.; Carvalho Junior, Alvaro D.; Santos, Wallans T. P. dos

    2014-01-01

    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 H 2 SO 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 -1 (r 2 = 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)

  7. Morphological and electrochemical properties of boron-doped diamond films on carbon cloths with enhanced surface area

    International Nuclear Information System (INIS)

    Silva, L.L.G.; Ferreira, N.G.; Corat, E.J.

    2008-01-01

    The electrochemical properties of doped diamond electrodes (10 17 -10 19 B cm -3 ) grown on carbon fiber cloths in H 2 SO 4 0.1 mol L -1 electrolyte were investigated. Cyclic voltammograms of B-doped diamond/carbon fiber cloth and carbon fiber cloth electrodes showed that both kinds of electrodes possess similar working potential windows of about 2.0 V. The electrode capacitance was determined by impedance spectroscopy and chronopotentiometry measurements and very close values were obtained. The capacitance values of the diamond film on carbon fiber cloths were 180 times higher than the ones of diamond films on Si. In this paper we have also discussed the capacitance frequency dependence of diamond/carbon cloth electrodes

  8. 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: 3.289, year: 2015

  9. Role of grain size in superconducting boron-doped nanocrystalline diamond thin films grown by CVD

    Czech Academy of Sciences Publication Activity Database

    Zhang, G.; Janssens, S.D.; Vanacken, J.; Timmermans, M.; Vacík, Jiří; Ataklti, G.W.; Decelle, W.; Gillijns, W.; Goderis, B.; Haenen, K.; Wagner, P.; Moshchalkov, V.V.

    2011-01-01

    Roč. 84, č. 21 (2011), 214517/1-214517/10 ISSN 1098-0121 Institutional research plan: CEZ:AV0Z10480505 Keywords : Nanocrystalline diamond * Superconducting transition Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.691, year: 2011

  10. 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

  11. Effect of boron dimers on the superconducting critical temperature inboron-doped diamond

    Czech Academy of Sciences Publication Activity Database

    Šopík, Břetislav; Lipavský, P.

    2012-01-01

    Roč. 21, č. 1 (2012), 77-82 ISSN 0925-9635 R&D Projects: GA ČR GAP204/10/0212 Institutional research plan: CEZ:AV0Z10100521 Keywords : boron * superconductivity * disorder * correlations * dimers Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.709, year: 2012

  12. Comparing atrazine and cyanuric acid electro-oxidation on mixed oxide and boron-doped diamond electrodes.

    Science.gov (United States)

    Malpass, Geoffroy R P; Salazar-Banda, Giancarlo R; Miwa, Douglas W; Machado, Sérgio A S; Motheo, Artur J

    2013-01-01

    The breakdown of pesticides has been promoted by many methods for clean up of contaminated soil and wastewaters. The main goal is to decrease the toxicity of the parent compound to achieve non-toxic compounds or even, when complete mineralization occurs, carbon dioxide and water. Therefore, electrochemical degradation (potentiostatic and galvanostatic) of both the pesticide atrazine and cyanuric acid (CA) at boron-doped diamond (BDD) and Ti/Ru0.3Ti0.7O2 dimensionally stable anode (DSA) electrodes, in different supporting electrolytes (NaCl and Na2SO4), is presented with the aim of establishing the influence of the operational parameters on the process efficiency. The results demonstrate that both the electrode material and the supporting electrolyte have a strong influence on the rate of atrazine removal. In the chloride medium, the rate of atrazine removal is always greater than in sulfate under all conditions employed. Furthermore, in the sulfate medium, atrazine degradation was significant only at the BDD electrode. The total organic carbon (TOC) load decreased by 79% and 56% at the BDD and DSA electrodes, respectively, in the chloride medium. This trend was maintained in the sulfate medium but the TOC removal was lower (i.e. 33% and 13% at BDD and DSA electrodes, respectively). CA, a stable atrazine degradation intermediate, was also studied and it is efficiently removed using the BDD electrode in both media, mainly when high current densities are employed. The use of the BDD electrode in the chloride medium not only degrades atrazine but also mineralized cyanuric acid leading to the higher TOC removal.

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

    International Nuclear Information System (INIS)

    Rocha, J.H. Bezerra; Gomes, M.M. Soares; Santos, E. Vieira dos; Moura, E.C. Martins de; Silva, D. Ribeiro da; Quiroz, M.A.; Martínez-Huitle, C.A.

    2014-01-01

    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

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

    International Nuclear Information System (INIS)

    Švorc, Ľubomír; Sochr, Jozef; Tomčík, Peter; Rievaj, Miroslav; Bustin, Dušan

    2012-01-01

    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

  15. 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.

  16. Boron-doped diamond electrooxidation of ethyl paraben: The effect of electrolyte on by-products distribution and mechanisms.

    Science.gov (United States)

    Frontistis, Zacharias; Antonopoulou, Maria; Yazirdagi, Melis; Kilinc, Zeynep; Konstantinou, Ioannis; Katsaounis, Alexandros; Mantzavinos, Dionissios

    2017-06-15

    Ethyl paraben (EP), a representative emerging pollutant of the parabens family, was subject to electrochemical oxidation over a boron-doped diamond (BDD) anode. Experiments were carried out in a single-compartment cell at 10-70 mA cm -2 current density, 200-600 μg L -1 EP concentration, initial solution pH 3-9 and 0.1 M electrolyte concentration. The degradation rate is favored at increased current densities and in the presence of NaCl as the supporting electrolyte, while the pH effect is inconsiderable. For instance, the first order rate constant for the degradation of 200 μg L -1 EP at 30 mA cm -2 was 0.25, 0.1 and 0.07 min -1 with NaCl, Na 2 SO 4 and HClO 4 , respectively. Degradation in secondary treated wastewater was faster than in pure water presumably due to the action of chloride ions present in the effluent. Liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS) was employed to determine major transformation by-products (TBPs). The route of EP degradation with Na 2 SO 4 involves hydroxylation and demethylation reactions, signifying the role of electrogenerated hydroxyl radicals in the process. Twenty one TBPs were identified with NaCl as the electrolyte, including several chlorinated and non-chlorinated dimers and trimers; these findings suggest that indirect oxidation mediated by chlorine radicals and other chlorine active species also takes place. In this view, the role of the supporting electrolyte is crucial since it can influence both reaction kinetics and pathways. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Boron-doped diamond oxidation of amoxicillin pharmaceutical formulation: Statistical evaluation of operating parameters, reaction pathways and antibacterial activity.

    Science.gov (United States)

    Frontistis, Zacharias; Antonopoulou, Maria; Venieri, Danae; Konstantinou, Ioannis; Mantzavinos, Dionissios

    2017-06-15

    The electrochemical oxidation of a commercial amoxicillin formulation over a boron-doped diamond (BDD) anode was investigated. The effect of initial COD concentration (1-2 g/L), current density (30-50 mA/cm 2 ), treatment time (15-90 min), initial pH (3-9) and electrolyte concentration (2-4 g/L NaCl) on COD removal was assessed through a factorial design methodology. For the range of conditions in question, the first three single effects, as well as the interaction between COD and time were the most important ones in terms of mass of COD removed. Liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS) was employed to identify major transformation by-products (TBPs); thirteen compounds were detected as TBPs of AMX electrochemical degradation, while several others appear in the original formulation. AMX degradation occurs though the following pathways: (i) hydroxylation mainly in the benzoic ring, (ii) opening of β-lactam ring followed by decarboxylation, hydroxylation and re-arrangement, and (iii) bond cleavage between the carbons of amino and amide groups. Furthermore, the process is accompanied by the release of several ions, i.e. nitrate, sulfate and ammonium. The antibiotic activity of AMX up to 1000 mg/L was tested against Klebsiella pneumoniae and Enterococcus faecalis reference strains; both bacteria are completely inactivated at this concentration but the activity is reduced substantially at lower concentrations. Oxidized samples still exhibit some antibacterial activity (50-60%) which is due to TBPs and active chlorine species present in the liquid phase. The latter are generated from chloride ions and enhance considerably AMX degradation rates. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Chemical Analysis of Impurity Boron Atoms in Diamond Using Soft X-ray Emission Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Muramatsu, Yasuji; Iihara, Junji; Takebe, Toshihiko; Denlinger, Jonathan D.

    2008-03-29

    To analyze the local structure and/or chemical states of boron atoms in boron-doped diamond, which can be synthesized by the microwave plasma-assisted chemical vapor deposition method (CVD-B-diamond) and the temperature gradient method at high pressure and high temperature (HPT-B-diamond), we measured the soft X-ray emission spectra in the CK and BK regions of B-diamonds using synchrotron radiation at the Advanced Light Source (ALS). X-ray spectral analyses using the fingerprint method and molecular orbital calculations confirm that boron atoms in CVD-B-diamond substitute for carbon atoms in the diamond lattice to form covalent B-C bonds, while boron atoms in HPT-B-diamond react with the impurity nitrogen atoms to form hexagonal boron nitride. This suggests that the high purity diamond without nitrogen impurities is necessary to synthesize p-type B-diamond semiconductors.

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

    International Nuclear Information System (INIS)

    Garbellini, Gustavo S.; Uliana, Carolina V.; Yamanaka, Hideko

    2013-01-01

    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 × 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)

  20. 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)

  1. 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.

  2. Influence of boron doping on mechanical and tribological properties ...

    Indian Academy of Sciences (India)

    On the other hand, nanocrystalline diamond (NCD) or ultra-NCD film has low surface roughness and fine nano-scaled grains. Therefore, a multilayer-diamond coating system was designed to improve the mechanical and tribological properties by combining the advantages of boron-doped diamond (BDD), MCD and. NCD.

  3. Substitutional Boron in Nanodiamond, Bucky-Diamond, and Nanocrystalline Diamond Grain Boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Barnard, Amanda S.; Sternberg, Michael G.

    2006-10-05

    Although boron has been known for many years to be a successful dopant in bulk diamond, efficient doping of nanocrystalline diamond with boron is still being developed. In general, the location, configuration, and bonding structure of boron in nanodiamond is still unknown, including the fundamental question of whether it is located within grains or grain boundaries of thin films and whether it is within the core or at the surface of nanoparticles. Presented here are density functional tight-binding simulations examining the configuration, potential energy surface, and electronic charge of substitutional boron in various types of nanocrystalline diamond. The results predict that boron is likely to be positioned at the surface of isolated particles and at the grain boundary of thin-film samples.

  4. Boron doped diamond electrodes for the dopamine identification by anodic stripping voltammetry

    International Nuclear Information System (INIS)

    Vojs, M.; Behul, M.; Michniak, P.; Rehacek, V.; Tvarozek, V.; Vesely, M.; Rossberg, M.; Schaaf, P.

    2012-01-01

    Polycrystalline BDD films 200-280 nm thick (Fig. 1) were produced in the double bias enhanced HF CVD reactor with sheet resistivity ∼ 100 Ω/sq. As a substrate, highly conductive (0.008-0.024 Ωcm) N (100) type silicon substrate was used with ∼ 200 nm wet SiO 2 oxide. Throughout the deposition, gas flows in reaction chamber were controlled to be 1 % CH 4 in H 2 and trymethylboron (TMB) in the range of 0-200 sccm (corresponding to 0-13 333 ppm of B/C). We have compared different measurements in presence of biological molecules (DA) with various BDD electrodes. These electrodes exhibited very high sensitivity, long-therm stability and high reproducibility. A very good performance (LOD = 6.02, R 2 =0.9921) of the BDD surface has been demonstrated only for very high 10 000 ppm B/C ratio (B doping levels n = 3.6·10 21 cm -3 ) for surface sensitive reactions in complex biological matrices. (authors)

  5. Investigation of a Cu/Pd Bimetallic System Electrodeposited on Boron-Doped Diamond Films for Application in Electrocatalytic Reduction of Nitrate

    Directory of Open Access Journals (Sweden)

    Jorge T. Matsushima

    2012-01-01

    Full Text Available The Cu/Pd bimetallic system electrodeposited on boron-doped diamond (BDD films for application, as electrode material in the electrochemical reduction of nitrate was studied. The electrochemical behavior of Cu, Pd, and Cu/Pd bimetallic system was evaluated by cyclic voltammetry. From these results, the formation of the Cu/Pd composite was verified. In addition, Cu with different phases and a Cu/Pd phase in the composite were obtained. Morphological analysis by scanning electron microscopy (SEM revealed a homogeneous distribution of Cu/Pd bimetallic particles with intermediary dimensions compared to those observed in Cu or Pd electrodeposits separately. These composites were tested as electrocatalysts for nitrate reduction in Britton-Robinson buffer solution (pH 9. Electrochemical measurements showed that composites with higher Cu content displayed the best electrocatalytic activity for nitrate reduction, and the Cu/Pd phase in the bimetallic system served to improve the Cu adherence on BDD electrode.

  6. 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.

  7. Electrochemically deposited Cu{sub 2}O cubic particles on boron doped diamond substrate as efficient photocathode for solar hydrogen generation

    Energy Technology Data Exchange (ETDEWEB)

    Mavrokefalos, Christos K. [Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, OX1 3TA, England (United Kingdom); Hasan, Maksudul, E-mail: maksudul.hasan@chem.ox.ac.uk [Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, OX1 3TA, England (United Kingdom); Tyndall National Institute, University College Cork, Lee Maltings, Cork (Ireland); Rohan, James F. [Tyndall National Institute, University College Cork, Lee Maltings, Cork (Ireland); Compton, Richard G. [Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QZ, England (United Kingdom); Foord, John S., E-mail: john.foord@chem.ox.ac.uk [Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, OX1 3TA, England (United Kingdom)

    2017-06-30

    Highlights: • Fabrication of low-cost photocathode by electrochemical method is described. • Boron-doped diamond is presented as catalyst support. • NiO nanoparticles on Cu{sub 2}O surface enhances photocurrent and electrode stability. • Synergy of metallic interaction between Cu and Ni leads to high efficiency. - Abstract: Herein, we report a novel photocathode for the water splitting reaction. The electrochemical deposition of Cu{sub 2}O particles on boron doped diamond (BDD) electrodes and the subsequent decoration with NiO nanoparticles by a dip coating method to act as co-catalyst for hydrogen evolution reaction is described. The morphology analysis by scanning electron microscope (SEM) revealed that Cu{sub 2}O particles are cubic and decorated sporadically with NiO nanoparticles. X-ray photoelectron spectroscopy (XPS) confirmed the electronic interaction at the interface between Cu{sub 2}O and NiO through a binding energy shift of the main Cu 2p peak. The photoelectrochemical (PEC) performance of NiO-Cu{sub 2}O/BDD showed a much higher current density (−0.33 mA/cm{sup 2}) and photoconversion efficiency (0.28%) compared to the unmodified Cu{sub 2}O/BDD electrode, which are only −0.12 mA/cm{sup 2} and 0.06%, respectively. The enhancement in PEC performance is attributable to the synergy of NiO as an electron conduction mediator leading to the enhanced charge separation and transfer to the reaction interface for hydrogen evolution as evidenced by electrochemical impedance spectroscopy (EIS) and charge carrier density calculation. Stability tests showed that the NiO nanoparticles loading content on Cu{sub 2}O surface is a crucial parameter in this regard.

  8. Study of the effects of focused high-energy boron ion implantation in diamond

    Science.gov (United States)

    Ynsa, M. D.; Agulló-Rueda, F.; Gordillo, N.; Maira, A.; Moreno-Cerrada, D.; Ramos, M. A.

    2017-08-01

    Boron-doped diamond is a material with a great technological and industrial interest because of its exceptional chemical, physical and structural properties. At modest boron concentrations, insulating diamond becomes a p-type semiconductor and at higher concentrations a superconducting metal at low temperature. The most conventional preparation method used so far, has been the homogeneous incorporation of boron doping during the diamond synthesis carried out either with high-pressure sintering of crystals or by chemical vapour deposition (CVD) of films. With these methods, high boron concentration can be included without distorting significantly the diamond crystalline lattice. However, it is complicated to manufacture boron-doped microstructures. A promising alternative to produce such microstructures could be the implantation of focused high-energy boron ions, although boron fluences are limited by the damage produced in diamond. In this work, the effect of focused high-energy boron ion implantation in single crystals of diamond is studied under different irradiation fluences and conditions. Micro-Raman spectra of the sample were measured before and after annealing at 1000 °C as a function of irradiation fluence, for both superficial and buried boron implantation, to assess the changes in the diamond lattice by the creation of vacancies and defects and their degree of recovery after annealing.

  9. Assessment of Boron Doped Diamond Electrode Quality and Application to In Situ Modification of Local pH by Water Electrolysis

    Science.gov (United States)

    Read, Tania L.; Macpherson, Julie V.

    2016-01-01

    Boron doped diamond (BDD) electrodes have shown considerable promise as an electrode material where many of their reported properties such as extended solvent window, low background currents, corrosion resistance, etc., arise from the catalytically inert nature of the surface. However, if during the growth process, non-diamond-carbon (NDC) becomes incorporated into the electrode matrix, the electrochemical properties will change as the surface becomes more catalytically active. As such it is important that the electrochemist is aware of the quality and resulting key electrochemical properties of the BDD electrode prior to use. This paper describes a series of characterization steps, including Raman microscopy, capacitance, solvent window and redox electrochemistry, to ascertain whether the BDD electrode contains negligible NDC i.e. negligible sp2 carbon. One application is highlighted which takes advantage of the catalytically inert and corrosion resistant nature of an NDC-free surface i.e. stable and quantifiable local proton and hydroxide production due to water electrolysis at a BDD electrode. An approach to measuring the local pH change induced by water electrolysis using iridium oxide coated BDD electrodes is also described in detail. PMID:26779959

  10. Electron Paramagnetic Resonance and X-ray Diffraction of Boron- and Phosphorus-Doped Nanodiamonds

    Science.gov (United States)

    Binh, Nguyen Thi Thanh; Dolmatov, V. Yu.; Lapchuk, N. M.; Shymanski, V. I.

    2017-11-01

    Powders of boron- and phosphorus-doped detonation nanodiamonds and sintered pellets of non-doped nanodiamond powders were studied using electron paramagnetic resonance and x-ray diffraction. Doping of detonation nanodiamond crystals with boron and phosphorus was demonstrated to be possible. These methods could be used to diagnose diamond nanocrystals doped during shock-wave synthesis.

  11. An All-Solid-State pH Sensor Employing Fluorine-Terminated Polycrystalline Boron-Doped Diamond as a pH-Insensitive Solution-Gate Field-Effect Transistor.

    Science.gov (United States)

    Shintani, Yukihiro; Kobayashi, Mikinori; Kawarada, Hiroshi

    2017-05-05

    A fluorine-terminated polycrystalline boron-doped diamond surface is successfully employed as a pH-insensitive SGFET (solution-gate field-effect transistor) for an all-solid-state pH sensor. The fluorinated polycrystalline boron-doped diamond (BDD) channel possesses a pH-insensitivity of less than 3mV/pH compared with a pH-sensitive oxygenated channel. With differential FET (field-effect transistor) sensing, a sensitivity of 27 mv/pH was obtained in the pH range of 2-10; therefore, it demonstrated excellent performance for an all-solid-state pH sensor with a pH-sensitive oxygen-terminated polycrystalline BDD SGFET and a platinum quasi-reference electrode, respectively.

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

    Science.gov (United States)

    Qiu, Cuicui; Yuan, Shi; Li, Xiang; Wang, Huijiao; Bakheet, Belal; Komarneni, Sridhar; Wang, Yujue

    2014-09-15

    Electrolysis and ozonation are two commonly used technologies for treating wastewaters contaminated with nitrophenol pollutants. However, they are often handicapped by their slow kinetics and low yields of total organic carbon (TOC) mineralization. To improve TOC mineralization efficiency, we combined electrolysis using a boron-doped diamond (BDD) anode with ozonation (electrolysis-O3) to treat a p-nitrophenol (PNP) aqueous solution. Up to 91% TOC was removed after 60 min of the electrolysis-O3 process. In comparison, only 20 and 44% TOC was respectively removed by individual electrolysis and ozonation treatment conducted under similar reaction conditions. The result indicates that when electrolysis and ozonation are applied simultaneously, they have a significant synergy for PNP mineralization. This synergy can be mainly attributed to (i) the rapid degradation of PNP to carboxylic acids (e.g., oxalic acid and acetic acid) by O3, which would otherwise take a much longer time by electrolysis alone, and (ii) the effective mineralization of the ozone-refractory carboxylic acids to CO2 by OH generated from multiple sources in the electrolysis-O3 system. The result suggests that combining electrolysis with ozonation can provide a simple and effective way to mutually compensate the limitations of the two processes for degradation of phenolic pollutants. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Propham mineralization in aqueous medium by anodic oxidation using boron-doped diamond anode: influence of experimental parameters on degradation kinetics and mineralization efficiency.

    Science.gov (United States)

    Ozcan, Ali; Sahin, Yücel; Koparal, A Savaş; Oturan, Mehmet A

    2008-06-01

    This study aims the removal of a carbamate herbicide, propham, from aqueous solution by direct electrochemical advanced oxidation process using a boron-doped diamond (BDD) anode. This electrode produces large quantities of hydroxyl radicals from oxidation of water, which leads to the oxidative degradation of propham up to its total mineralization. Effect of operational parameters such as current, temperature, pH and supporting electrolyte on the degradation and mineralization rate was studied. The applied current and temperature exert a prominent effect on the total organic carbon (TOC) removal rate of the solutions. The mineralization of propham can be performed at any pH value between 3 and 11 without any loss in oxidation efficiency. The propham decay and its overall mineralization reaction follows a pseudo-first-order kinetics. The apparent rate constant value of propham oxidation was determined as 4.8 x 10(-4)s(-1) at 100 mA and 35 degrees C in the presence of 50mM Na(2)SO(4) in acidic media (pH: 3). A general mineralization sequence was proposed considering the identified oxidation intermediates.

  14. 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)

    Vahid, Behrouz; Khataee, Alireza

    2013-01-01

    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 (E EO ), 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

  15. An Experimental Approach to Controllably Vary Protein Oxidation While Minimizing Electrode Adsorption for Boron-Doped Diamond Electrochemical Surface Mapping Applications

    Science.gov (United States)

    McClintock, Carlee S; Hettich, Robert L.

    2012-01-01

    Oxidative protein surface mapping has become a powerful approach for measuring the solvent accessibility of folded protein structures. A variety of techniques exist for generating the key reagent – hydroxyl radicals – for these measurements; however, these approaches range significantly in their complexity and expense of operation. This research expands upon earlier work to enhance the controllability of boron-doped diamond (BDD) electrochemistry as an easily accessible tool for producing hydroxyl radicals in order to oxidize a range of intact proteins. Efforts to modulate oxidation level while minimizing the adsorption of protein to the electrode involved the use of relatively high flow rates to reduce protein residence time inside the electrochemical flow chamber. Additionally, a different cell activation approach using variable voltage to supply a controlled current allowed us to precisely tune the extent of oxidation in a protein-dependent manner. In order to gain perspective on the level of protein adsorption onto the electrode surface, studies were conducted to monitor protein concentration during electrolysis and gauge changes in the electrode surface between cell activation events. This report demonstrates the successful use of BDD electrochemistry for greater precision in generating a target number of oxidation events upon intact proteins. PMID:23210708

  16. Electrochemical Oxidation of Resorcinol in Aqueous Medium Using Boron-Doped Diamond Anode: Reaction Kinetics and Process Optimization with Response Surface Methodology.

    Science.gov (United States)

    Körbahti, Bahadır K; Demirbüken, Pelin

    2017-01-01

    Electrochemical oxidation of resorcinol in aqueous medium using boron-doped diamond anode (BDD) was investigated in a batch electrochemical reactor in the presence of Na 2 SO 4 supporting electrolyte. The effect of process parameters such as resorcinol concentration (100-500 g/L), current density (2-10 mA/cm 2 ), Na 2 SO 4 concentration (0-20 g/L), and reaction temperature (25-45°C) was analyzed on electrochemical oxidation using response surface methodology (RSM). The optimum operating conditions were determined as 300 mg/L resorcinol concentration, 8 mA/cm 2 current density, 12 g/L Na 2 SO 4 concentration, and 34°C reaction temperature. One hundred percent of resorcinol removal and 89% COD removal were obtained in 120 min reaction time at response surface optimized conditions. These results confirmed that the electrochemical mineralization of resorcinol was successfully accomplished using BDD anode depending on the process conditions, however the formation of intermediates and by-products were further oxidized at much lower rate. The reaction kinetics were evaluated at optimum conditions and the reaction order of electrochemical oxidation of resorcinol in aqueous medium using BDD anode was determined as 1 based on COD concentration with the activation energy of 5.32 kJ/mol that was supported a diffusion-controlled reaction.

  17. 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

    2014-01-07

    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.

  18. Enhancing the electrochemical oxidation of acid-yellow 36 azo dye using boron-doped diamond electrodes by addition of ferrous ion

    Energy Technology Data Exchange (ETDEWEB)

    Villanueva-Rodriguez, M.; Hernandez-Ramirez, A. [Universidad Autonoma de Nuevo Leon, Facultad de Ciencias Quimicas, Av. Universidad s/n, Cd. Universitaria, San Nicolas de los Garza, NL. 66400 (Mexico); Peralta-Hernandez, J.M., E-mail: jperalta@fcq.uanl.mx [Universidad Autonoma de Nuevo Leon, Facultad de Ciencias Quimicas, Av. Universidad s/n, Cd. Universitaria, San Nicolas de los Garza, NL. 66400 (Mexico); Bandala, Erick R.; Quiroz-Alfaro, Marco A. [Universidad de Las Americas - Puebla, Escuela de Ingenieria y Ciencias, Sta. Catarina Martir - Cholula, Puebla 72820 (Mexico)

    2009-08-15

    This work shows preliminary results on the electrochemical oxidation process (EOP) using boron-doped diamond (BDD) electrode for acidic yellow 36 oxidation, a common azo dye used in textile industry. The study is centred in the synergetic effect of ferrous ions and hydroxyl free radicals for improving discoloration of azo dye. The assays were carried out in a typical glass cell under potentiostatic conditions. On experimental conditions, the EOP was able to partially remove the dye from the reaction mixture. The reaction rate increased significantly by addition of Fe{sup 2+} (1 mM as ferrous sulphate) to the system and by (assumed) generation of ferrate ion [Fe(VI)] over BDD electrode. Ferrate is considered as a highly oxidizing reagent capable of removing the colorant from the reaction mixture, in synergistic action with the hydroxyl radicals produced on the BDD surface. Further increases in the Fe{sup 2+} concentration lead to depletion of the reaction rate probably due to the hydroxyl radical scavenging effect of Fe{sup 2+} excess in the system.

  19. Electrochemical treatment of anti-cancer drug carboplatin on mixed-metal oxides and boron doped diamond electrodes: Density functional theory modelling and toxicity evaluation.

    Science.gov (United States)

    Barışçı, Sibel; Turkay, Ozge; Ulusoy, Ebru; Soydemir, Gülfem; Seker, Mine Gul; Dimoglo, Anatoli

    2018-02-15

    This study represents the electrooxidation of anti-cancer drug carboplatin (CrbPt) with different mixed metal oxide (MMO) and boron doped diamond (BDD) electrodes. The most effective anode was found as Ti/RuO 2 with the complete degradation of CrbPt in just 5min. The effect of applied current density, pH and electrolyte concentration on CrbPt degradation has been studied. The degradation of CrbPt significantly increased at the initial stages of the process with increasing current density. However, further increase in current density did not affect the degradation rate. While complete degradation of CrbPt was provided at pH 7, the degradation rates were 49% and 75% at pH 9 and 4, respectively. Besides, increasing supporting electrolyte (Na 2 SO 4 ) concentration provided higher degradation rate but further increase in Na 2 SO 4 concentration did not provide higher degradation rate due to excess amount of SO 4 -2 . According to the DFT calculations, the formation of [Pt(NH 3 ) 2 (H 2 O) 2 ] 2+ and [Pt(NH 3 ) 2 (OH) 2 ] takes place with molecular weights of 265 and 263gmol -1 , respectively. Toxicity of treated samples at BDD and Ti/RuO 2 electrodes has been also evaluated in this study. The results showed that Ti/RuO 2 anode provided zero toxicity at the end of the process. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Determination of organophosphate pesticides using an acetylcholinesterase-based biosensor based on a boron-doped diamond electrode modified with gold nanoparticles and carbon spheres

    International Nuclear Information System (INIS)

    Wei, Min; Zeng, Gaoying; Lu, Qiyu

    2014-01-01

    We report on a biosensor for organophosphate pesticides (OPs) by exploiting their inhibitory effect on the activity of acetylcholinesterase (AChE). A boron-doped diamond (BDD) electrode was modified with a nanocomposite prepared from carbon spheres (CSs; with an average diameter of 500 nm) that were synthesized from resorcinol and formaldehyde, and then were coated with gold nanoparticles (AuNPs) by chemically growing them of the CSs. Compared to a bare BDD electrode, the electron transfer resistance is lower on this new electrode. Compared to an electrode without Au-NPs, the peak potential is negatively shifted by 42 mV, and the peak current is increased by 55 %. This is ascribed to the larger surface in the AuNP-CS nanocomposite which improves the adsorption of AChE, enhances its activity, and facilitates electrocatalysis. Under optimum conditions, the inhibitory effect of chlorpyrifos is linearly related to the negative log of its concentration in the 10−11 to 10−7 M range, with a detection limit of 1.3 × 10 −13 M. For methyl parathion, the inhibition effect is linear in the 10 −12 to 10 −6 M range, and the detection limit is 4.9 × 10 −13 M. The biosensor exhibits good precision and acceptable operational and temporal stability. (author)

  1. Electrochemical Oxidation of Resorcinol in Aqueous Medium Using Boron-Doped Diamond Anode: Reaction Kinetics and Process Optimization with Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Bahadır K. Körbahti

    2017-10-01

    Full Text Available Electrochemical oxidation of resorcinol in aqueous medium using boron-doped diamond anode (BDD was investigated in a batch electrochemical reactor in the presence of Na2SO4 supporting electrolyte. The effect of process parameters such as resorcinol concentration (100–500 g/L, current density (2–10 mA/cm2, Na2SO4 concentration (0–20 g/L, and reaction temperature (25–45°C was analyzed on electrochemical oxidation using response surface methodology (RSM. The optimum operating conditions were determined as 300 mg/L resorcinol concentration, 8 mA/cm2 current density, 12 g/L Na2SO4 concentration, and 34°C reaction temperature. One hundred percent of resorcinol removal and 89% COD removal were obtained in 120 min reaction time at response surface optimized conditions. These results confirmed that the electrochemical mineralization of resorcinol was successfully accomplished using BDD anode depending on the process conditions, however the formation of intermediates and by-products were further oxidized at much lower rate. The reaction kinetics were evaluated at optimum conditions and the reaction order of electrochemical oxidation of resorcinol in aqueous medium using BDD anode was determined as 1 based on COD concentration with the activation energy of 5.32 kJ/mol that was supported a diffusion-controlled reaction.

  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. 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)

    Taylor, G.T.; Newey, A.W.E.; Bates, C.J.; King, C.R.; Dawes, K.

    2009-01-01

    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 m 2 , 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)

  4. Serial coupling of RP and zwitterionic hydrophilic interaction LC-MS: suspects screening of diclofenac transformation products by oxidation with a boron-doped diamond electrode.

    Science.gov (United States)

    Rajab, Mohamad; Greco, Giorgia; Heim, Carolin; Helmreich, Brigitte; Letzel, Thomas

    2013-09-01

    The presence of pollutants and their transformation products (TPs) in the water system is a big concern because of possible adverse effects on the aquatic environment. Their identification is still a challenge that requires the combination of different chromatographic techniques. In the current research, serial coupling of RPLC and zwitterionic hydrophilic interaction LC with TOF-MS was investigated as a single separation technique for the screening of suspected TPs from electrochemical oxidation of diclofenac using a boron-doped diamond electrode. Diclofenac oxidation was performed in three water matrices in order to study its transformation in different chemical contexts. 47 TPs resulting from similar oxidation methods were selected from the literature. As in most cases standards were not available, an identification procedure based on accurate mass data and chromatographic behavior was proposed. According to this procedure, 11 suspected TPs, previously analyzed by LC, GC, or ion chromatography, were detected in a single injection. The method was proved to be reliable and versatile and it could be efficiently employed as a comprehensive analytical tool for the simultaneous analysis of compounds in a wide polarity range. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    International Nuclear Information System (INIS)

    Zhu Xiuping; Ni Jinren

    2011-01-01

    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., FeO 2+ , FeO 4 2− ) was enhanced by direct electrochemical oxidation at BDD anode.

  6. Chemical Analysis of Impurity Boron Atoms in Diamond Using Soft X-ray Emission Spectroscopy

    OpenAIRE

    Muramatsu, Yasuji

    2009-01-01

    To analyze the local structure and/or chemical states of boron atoms in boron-doped diamond, which can be synthesized by the microwave plasma-assisted chemical vapor deposition method (CVD-B-diamond) and the temperature gradient method at high pressure and high temperature (HPT-B-diamond), we measured the soft X-ray emission spectra in the CK and BK regions of B-diamonds using synchrotron radiation at the Advanced Light Source (ALS). X-ray spectral analyses using the fingerprint method and mo...

  7. Superconductivity in heavily boron-doped silicon carbide

    OpenAIRE

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

    2008-01-01

    The discoveries of superconductivity in heavily boron-doped diamond (C:B) in 2004 and silicon (Si:B) in 2006 renew 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 (SiC:B). The sample used for that study consists of cubic and hexagonal SiC ph...

  8. Preparation and Cutting Performance of Boron-Doped Diamond Coating on Cemented Carbide Cutting Tools with High Cobalt Content

    OpenAIRE

    Zhaozhi Liu; Feng Xu; Junhua Xu; Xiaolong Tang; Ying Liu; Dunwen Zuo

    2015-01-01

    Chemical vapor deposition (CVD) diamond coated cutting tool has excellent cutting performance, it is the most ideal tool for the processing of nonferrous metals and alloys, composites, nonmetallic materials and other difficult-to-machine materials efficiently and accurately. Depositing CVD diamond coating on the cemented carbide with high cobalt content can improve its toughness and strength, therefore, it is very important to research on the preparation technology and cu...

  9. 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)

    Barros, Willyam R.P.; Steter, Juliana R.; Lanza, Marcos R.V.; Motheo, Artur J.

    2014-01-01

    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

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

    Science.gov (United States)

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

    2014-05-20

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

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

    International Nuclear Information System (INIS)

    Flox, Cristina; Garrido, Jose Antonio; Rodriguez, Rosa Maria; Centellas, Francesc; Cabot, Pere-Lluis; Arias, Conchita; Brillas, Enric

    2005-01-01

    Anodic oxidation of 4,6-dinitro-o-cresol (DNOC) has been studied in a cell of 100 ml with a boron-doped diamond anode and a graphite cathode, both of 3-cm 2 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 NO 3 - 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

  12. A novel paper-based device coupled with a silver nanoparticle-modified boron-doped diamond electrode for cholesterol detection

    Energy Technology Data Exchange (ETDEWEB)

    Nantaphol, Siriwan [Electrochemistry and Optical Spectroscopy Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok 10330 (Thailand); Chailapakul, Orawon, E-mail: corawon@chula.ac.th [Electrochemistry and Optical Spectroscopy Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok 10330 (Thailand); Center for Petroleum, Petrochemicals and Advanced Materials, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok 10330 (Thailand); Siangproh, Weena, E-mail: weenasi@hotmail.com [Department of Chemistry, Faculty of Science, Srinakharinwirot University, Sukhumvit 23, Wattanna, Bangkok 10110 (Thailand)

    2015-09-03

    A novel paper-based analytical device (PAD) coupled with a silver nanoparticle-modified boron-doped diamond (AgNP/BDD) electrode was first developed as a cholesterol sensor. The AgNP/BDD electrode was used as working electrode after modification by AgNPs using an electrodeposition method. Wax printing was used to define the hydrophilic and hydrophobic areas on filter paper, and then counter and reference electrodes were fabricated on the hydrophilic area by screen-printing in house. For the amperometric detection, cholesterol and cholesterol oxidase (ChOx) were directly drop-cast onto the hydrophilic area, and H{sub 2}O{sub 2} produced from the enzymatic reaction was monitored. The fabricated device demonstrated a good linearity (0.39 mg dL{sup −1} to 270.69 mg dL{sup −1}), low detection limit (0.25 mg dL{sup −1}), and high sensitivity (49.61 μA mM{sup −1} cm{sup −2}). The precision value for ten replicates was 3.76% RSD for 1 mM H{sub 2}O{sub 2}. In addition, this biosensor exhibited very high selectivity for cholesterol detection and excellent recoveries for bovine serum analysis (in the range of 99.6–100.8%). The results showed that this new sensing platform will be an alternative tool for cholesterol detection in routine diagnosis and offers the advantages of low sample/reagent consumption, low cost, portability, and short analysis time. - Highlights: • Novel PAD coupled with AgNP/BDDE for cholesterol determination was developed. • Wide linear range, low detection limit and high selectivity were achieved. • This sensor was successfully applied for cholesterol determination in bovine serum. • This platform offers the advantages of low sample/reagent consumption and low cost.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-09-15

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

  14. AFM studies and electrochemical characterization of boron-doped diamond surfaces modified with metal oxides by the Sol-Gel method

    Directory of Open Access Journals (Sweden)

    Suffredini Hugo B.

    2006-01-01

    Full Text Available 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 Nafion® 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 Nafion® 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.

  15. Erratum to: Influence of boron doping on mechanical and tribological ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Erratum to: Influence of boron doping on mechanical and tribological properties in multilayer CVD-diamond coating systems. SAJAD HUSSAIN DIN M A SHAH N A SHEIKH K A NAJAR K RAMASUBRAMANIAN S BALAJI M S RAMACHANDRA RAO. Volume 39 Issue 7 December 2016 pp 1763-1763 ...

  16. Influence of boron doping on mechanical and tribological properties ...

    Indian Academy of Sciences (India)

    Influence of boron doping on mechanical and tribological properties in multilayer CVD-diamond coating systems. SAJAD HUSSAIN DIN1,∗, M A SHAH2, N A SHEIKH1, K A NAJAR1, K RAMASUBRAMANIAN3,. S BALAJI3 and M S RAMACHANDRA RAO3. 1Department of Mechanical Engineering, National Institute of ...

  17. Influence of boron doping on mechanical and tribological properties ...

    Indian Academy of Sciences (India)

    Titanium alloy (Ti6Al4V) substrates were deposited with smooth multilayer coatings, by hot filament chemical vapour deposition technique. The effect of boron doping on lattice parameter, residual stresses, hardness and coefficient of friction in multilayer-diamond coating system was studied. The frictional behaviour of the ...

  18. Development and application of a labmade apparatus using open-source “arduino” hardware for the electrochemical pretreatment of boron-doped diamond electrodes

    International Nuclear Information System (INIS)

    Rosa, Thalles Ramon; Betim, Fernando Silva; Ferreira, Rafael de Queiroz

    2017-01-01

    Highlights: • BDD electrodes use an electrochemical pretreatment (anodic and/or cathodic) to restore their original characteristics and promote the reproduction of previous voltammograms; • Automatic system can carefully reproduce the electrochemical pretreatment of BDD electrode quickly and efficiently; • Open source platform “Arduino” can be used to developed a labmade apparatus to control a BDD electrode pretreatment system for analytical purposes; • The main advantages of this labmade apparatus are: low supporting electrolyte consumption (20 mL), a total time for each pretreatment of 80 seconds and an average cost of production below US$ 200. - Abstract: Every day, new electroanalytical methodologies are developed to supplant the established spectrometric and chromatographic methods due to their versatility, low cost and ability to perform measurements without sample treatment. Electroanalytical techniques have provided an alternative to quantify substances due to the direct relationship between the analyte concentration and some electrical property of the system. However, this ratio between the concentration and peak current is valid only if the electrochemically active area of the working electrode is constant in each electrochemical test. For years, classic polarography ensured the reproducibility of the mercury electrode surface due to its liquid state at room temperature. However, this metal has a high toxicity, driving the search for new inert materials for their replacement, most notably boron-doped diamond (BDD) electrodes. This electrode material has, among other attractive advantages for electroanalysis, a potential range higher than that of the mercury working electrode under the same conditions. Solid electrodes are, in general, polished to promote the reproducibility of their electrochemical performance. For BDD, the use of an electrochemical pretreatment (anodic and/or cathodic) has been sufficient to restore their original

  19. 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)

    Švorc, Ľubomír; Sochr, Jozef; Svítková, Jana; Rievaj, Miroslav; Bustin, Dušan

    2013-01-01

    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 (R 2 = 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

  20. Architecting boron nanostructure on the diamond particle surface

    International Nuclear Information System (INIS)

    Bai, H.; Dai, D.; Yu, J.H.; Nishimura, K.; Sasaoka, S.; Jiang, N.

    2014-01-01

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

  1. Nanopores creation in boron and nitrogen doped polycrystalline graphene: A molecular dynamics study

    Science.gov (United States)

    Izadifar, Mohammadreza; Abadi, Rouzbeh; Nezhad Shirazi, Ali Hossein; Alajlan, Naif; Rabczuk, Timon

    2018-05-01

    In the present paper, molecular dynamic simulations have been conducted to investigate the nanopores creation on 10% of boron and nitrogen doped polycrystalline graphene by silicon and diamond nanoclusters. Two types of nanoclusters based on silicon and diamond are used to investigate their effect for the fabrication of nanopores. Therefore, three different diameter sizes of the clusters with five kinetic energies of 10, 50, 100, 300 and 500 eV/atom at four different locations in boron or nitrogen doped polycrystalline graphene nanosheets have been perused. We also study the effect of 3% and 6% of boron doped polycrystalline graphene with the best outcome from 10% of doping. Our results reveal that the diamond cluster with diameter of 2 and 2.5 nm fabricates the largest nanopore areas on boron and nitrogen doped polycrystalline graphene, respectively. Furthermore, the kinetic energies of 10 and 50 eV/atom can not fabricate nanopores in some cases for silicon and diamond clusters on boron doped polycrystalline graphene nanosheets. On the other hand, silicon and diamond clusters fabricate nanopores for all locations and all tested energies on nitrogen doped polycrystalline graphene. The area sizes of nanopores fabricated by silicon and diamond clusters with diameter of 2 and 2.5 nm are close to the actual area size of the related clusters for the kinetic energy of 300 eV/atom in all locations on boron doped polycrystalline graphene. The maximum area and the average maximum area of nanopores are fabricated by the kinetic energy of 500 eV/atom inside the grain boundary at the center of the nanosheet and in the corner of nanosheet with diameters of 2 and 3 nm for silicon and diamond clusters on boron and nitrogen doped polycrystalline graphene.

  2. Investigation of electrochemical behavior of lipid lowering agent atorvastatin calcium in aqueous media and its determination from pharmaceutical dosage forms and biological fluids using boron-doped diamond and glassy carbon electrodes.

    Science.gov (United States)

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

    2007-08-01

    The electrochemical behavior of atorvastatin calcium at glassy carbon and boron-doped diamond electrodes has been studied using voltammetric techniques. The possible mechanism of oxidation was discussed with model compounds. The dependence of the peak current and potentials on pH, concentration, scan rate and nature of the buffer were investigated for both electrodes. The oxidation of atorvastatin was irreversible and exhibited a diffusion-controlled fashion on the diamond electrode. A linear response was obtained within the range of 9.65 x 10(-7) - 3.86 x 10(-5) M in 0.1 M H(2)SO(4) solution for both electrodes. The detection limits of a standard solution are estimated to be 2.11 x 10(-7) M with differential pulse voltammetry (DPV) and 2.05 x 10(-7)M with square wave voltammetry (SWV) for glassy carbon electrode, and 2.27 x 10(-7) M with DPV and 1.31 x 10(-7)M with SWV for diamond electrodes in 0.1 M H(2)SO(4) solution. The repeatability of the methods was found good for both electrodes. The methods were fully validated and successfully applied to the high-throughput determination of the drug in tablets, human serum and human urine with good recoveries.

  3. Application of electrochemical advanced oxidation processes with a boron-doped diamond anode to degrade acidic solutions of Reactive Blue 15 (Turqueoise Blue) dye

    International Nuclear Information System (INIS)

    Solano, Aline Maria Sales; Martínez-Huitle, Carlos Alberto; Garcia-Segura, Sergi; El-Ghenymy, Abdellatif

    2016-01-01

    Highlights: • Degradation of Reactive Blue 15 solution at pH 3.0 by electrochemical oxidation, electro-Fenton and photoelectro-Fenton. • Hard destruction of the dye and its products by BDD(·OH) and much more rapidly by ·OH. • 94% mineralization by the most powerful photoelectro-Fenton at 66.7 mA cm −2 , with acetic acid accumulation. • 25 aromatics and heteroaromatics, 30 hydroxylated derivatives and 4 carboxylic acids as products. • Release of Cl − , SO 4 2− and pre-eminently NO 3 − during dye mineralization. - Abstract: The degradation of the copper-phthalocyanine dye Reactive Blue 15 dye in sulfate medium has been comparatively studied by electrochemical oxidation with electrogenerated H 2 O 2 (EO-H 2 O 2 ), electro-Fenton (EF) and photoelectro-Fenton (PEF). Experiments with 100 cm 3 solutions of 0.203 mmol dm −3 dye were performed with a stirred tank reactor containing a boron-doped diamond (BDD) anode and an air-diffusion cathode for continuous H 2 O 2 production. Experimental conditions of pH 3.0 and 0.50 mmol dm −3 Fe 2+ as catalyst were found optimal for the EF process by the predominant oxidation with hydroxyl radicals formed in the bulk from Fenton’s reaction between added Fe 2+ and generated H 2 O 2 . The kinetics of Reactive Blue 15 abatement was followed by reversed-phase HPLC and always obeyed a pseudo-first-order reaction. The decolorization rate in EO-H 2 O 2 was much lower than dye decay due to the formation of large quantities of colored intermediates under the action of hydroxyl radicals generated at the BDD anode from water oxidation. In contrast, the color and dye removals were much more rapid in EF and PEF by the most efficient oxidation of hydroxyl radicals produced from Fenton’s reaction. PEF was the most powerful treatment owing to the photolytic action of UVA irradiation, yielding 94% mineralization after 360 min at 66.7 mA cm −2 . The effect of current density over the performance of all methods was examined

  4. 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.

  5. Superconductivity in heavily boron-doped silicon carbide.

    Science.gov (United States)

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

    2008-12-01

    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.

  6. Square-wave voltammetric determination of fungicide fenfuram in real samples on bare boron-doped diamond electrode, and its corrosion properties on stainless steels used to produce agricultural tools

    International Nuclear Information System (INIS)

    Brycht, Mariola; Skrzypek, Sławomira; Kaczmarska, Kinga; Burnat, Barbara; Leniart, Andrzej; Gutowska, Natalia

    2015-01-01

    Graphical abstract: Display Omitted -- Highlights: • A bare boron-doped diamond electrode was first used to determine fenfuram. • A sensitive voltammetric procedure for the determination of fenfuram was developed. • The sensor showed high sensitivity, selectivity, and wide linear range. • The procedure was successfully applied to detect fenfuram in real samples. • The effect of fenfuram on the uniform and pitting corrosion of steel was stated. -- Abstract: A simple, selective, and sensitive electroanalytical method for the determination of a novel fungicide, fenfuram (Fnf), on a bare boron-doped diamond electrode (BDDE) using square-wave voltammetry (SWV) was developed. For the first time, the electrochemical oxidation of Fnf at BDDE at about 1.5 V vs. Ag/AgCl reference electrode in 0.35 mol L −1 sulfuric acid was investigated. To select the optimum experimental conditions, the effects of the supporting electrolyte, pH, frequency, amplitude, and step potential were studied. The developed method allowed the determination of Fnf in the concentration range of 2.4 × 10 −5 to 2.6 × 10 −4 mol L −1 (LOD = 6.3 × 10 −6 mol L −1 , LOQ = 2.1 × 10 −5 mol L −1 ). The validation of the method was carried out. The proposed procedure was successfully applied to determine Fnf in the spiked natural water samples collected from Polish rivers and in the spiked triticale seed samples by the standard addition method. To understand the Fnf electrode mechanism, the cyclic voltammetry (CV) technique was applied. The oxidation mechanism was also confirmed using mass spectrometry with the electrospray ionization (ESI-MS) technique. Using electrochemical techniques, the effect of Fnf on the corrosion properties of stainless steel which is used to produce agricultural tools was studied

  7. Stabilization of boron carbide via silicon doping.

    Science.gov (United States)

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

    2015-01-14

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

  8. Electronic Structures of Aluminum-Doped Diamond near the Fermi Level

    Science.gov (United States)

    Mori, Masaki; Saeki, Yosuke; Hakamata, Masaki; Sato, Takuya; Kabasawa, Eiki; Nakamura, Jin

    2015-04-01

    Aluminum-doped diamond samples were synthesized using the conventional microwave plasma chemical vapor deposition method. The electronic structures were measured using an electron probe microanalyzer and by X-ray photoelectron spectroscopy. The area intensity of the partial profile of Al-3p near the Fermi level increased with increasing aluminum concentration in the sample. The partial profile of Al-3p resembles that of C-2p at high aluminum concentrations, which suggests strong hybridization between Al-3p and C-2p. Additionally, the temperature dependence of the electric resistance yields an activation energy of 8.2 meV at room temperature. The present results suggest the metal-insulator transition of aluminum-doped diamond, similar to that of boron-doped diamond. However, with increasing aluminum concentration, a considerable amount of carriers is not doped to C-2p orbitals in aluminum-doped diamond. The present results indicate that superconductivity in aluminum-doped diamond with the same mechanism as that in boron-doped diamond does not occur.

  9. Role of electrode materials for the anodic oxidation of a real landfill leachate--comparison between Ti-Ru-Sn ternary oxide, PbO(2) and boron-doped diamond anode.

    Science.gov (United States)

    Panizza, Marco; Martinez-Huitle, Carlos A

    2013-01-01

    In this paper the electrocatalytic properties of Ti-Ru-Sn ternary oxide (TiRuSnO(2)), PbO(2) and boron-doped diamond (BDD) anodes have been compared for the electrochemical oxidation of a real landfill leachate from an old municipal solid waste landfill (average values of COD 780 mg dm(-3) and NH(4)(+)-N266 mg dm(-3)). The experiments have been performed using an undivided flow cell equipped with a stainless steel cathode, under constant current of 2 A and flow-rate of 420 dm(3) h(-1). The performance of the electrodes has been compared measuring the time evolution of aromatic compounds, COD, ammonium, colour removal, current efficiency and energy consumption. The experimental results indicated that after 8 h of electrolyses TiRuSnO(2) anode yields only 35% COD, 52% colour and 65% ammonium removal. Using PbO(2) ammonium and colour were completely removed but a residual COD (i.e. 115 mg dm(-3)) was present. On the contrary BDD enables complete COD, colour and ammonium removal due to the electrogeneration of hydroxyl radicals from water discharge and active chlorine from chloride ions oxidation. BDD also exhibits greater current efficiency along with a significantly lower energy cost than other electrodes. These results indicated that the electrochemical oxidation with BDD anode is an effective process for the treatment of landfill leachate. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. 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)

  11. A multidimensional high performance liquid chromatography method coupled with amperometric detection using a boron-doped diamond electrode for the simultaneous determination of sulfamethoxazole and trimethoprim in bovine milk

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Leonardo S.; Moraes, Marcela C. de; Rocha-Filho, Romeu C.; Fatibello-Filho, Orlando [Departamento de Quimica, Universidade Federal de Sao Carlos, C.P. 676, 13560-970 Sao Carlos - SP (Brazil); Cass, Quezia B., E-mail: quezia@pesquisador.cnpq.br [Departamento de Quimica, Universidade Federal de Sao Carlos, C.P. 676, 13560-970 Sao Carlos - SP (Brazil)

    2009-11-10

    The development and validation of a multidimensional HPLC method using an on-line clean-up column coupled with amperometric detection employing a boron-doped diamond (BDD) electrode for the simultaneous determination of sulfamethoxazole (SMX) and trimethoprim (TMP) in bovine milk are presented. Aliquots of pre-prepared skim-milk samples were directly injected into a RAM octyl-BSA column in order to remove proteins that otherwise would interfere with milk analysis. After exclusion of the milk proteins, SMX and TMP were transferred to the analytical column (an octyl column) and the separation of the compounds from one another and from other endogenous milk components was achieved. SMX and TMP were detected amperometrically at 1.25 V vs. Ag/AgCl (3.0 mol L{sup -1} KCl). Results with good linearity in the concentration ranges 50-800 and 25-400 {mu}g L{sup -1} for SMX and TMP, respectively, were obtained and no fouling of the BDD electrode was observed within the experimental period of several hours. The intra- and inter-assay coefficients of variation were less than 10% for both drugs and the obtained LOD values for SMX and TMP were 25.0 and 15.0 {mu}g L{sup -1}, respectively.

  12. 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)

    Costa, Carla Regina; Montilla, Francisco; Morallon, Emilia; Olivi, Paulo

    2009-01-01

    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.

  13. XPS analysis of boron doped heterofullerenes

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-06-01

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

  14. Properties of hybridized DNA arrays on single-crystalline undoped and boron-doped (100) diamonds studied by Atomic Force Microscopy in electrolytes

    Czech Academy of Sciences Publication Activity Database

    Rezek, Bohuslav; Shin, D.; Nebel, C.E.

    2007-01-01

    Roč. 23, - (2007), s. 7626-7633 ISSN 0743-7463 Institutional research plan: CEZ:AV0Z10100521 Keywords : diamond * DNA * AFM * electrolytes Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.009, year: 2007

  15. 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

    International Nuclear Information System (INIS)

    Skoumal, Marcel; Rodriguez, Rosa Maria; Cabot, Pere Lluis; Centellas, Francesc; Garrido, Jose Antonio; Arias, Conchita; Brillas, Enric

    2009-01-01

    The degradation of a 41 mg dm -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 2 -diffusion cathode. Heterogeneous hydroxyl radical (·OH) is generated at the anode surface from water oxidation, while homogeneous ·OH is formed from Fenton's reaction between Fe 2+ and H 2 O 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 ·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 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Ynsa, M.D., E-mail: m.ynsa@uam.es [Centro de Micro-Análisis de Materiales, Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Departamento de Física Aplicada, Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Ramos, M.A. [Centro de Micro-Análisis de Materiales, Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Departamento de Física de la Materia Condensada and Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Skukan, N. [Laboratory for Ion Beam Interactions, Ruđer Bošković Institute, Bijenička 54, HR-10000 Zagreb (Croatia); Torres-Costa, V. [Centro de Micro-Análisis de Materiales, Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Departamento de Física Aplicada, Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Jakšić, M. [Laboratory for Ion Beam Interactions, Ruđer Bošković Institute, Bijenička 54, HR-10000 Zagreb (Croatia)

    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 μm{sup 2} 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 {sup 11}B(p, α){sup 8}Be at E{sub p} = 660 keV. This reaction has a high Q-value (8.59 MeV for α{sub 0} and 5.68 MeV for α{sub 1}) and thus is almost interference-free. The sensitivity of the technique is studied in this work.

  17. Plasmonic Properties of Silicon Nanocrystals Doped with Boron and Phosphorus.

    Science.gov (United States)

    Kramer, Nicolaas J; Schramke, Katelyn S; Kortshagen, Uwe R

    2015-08-12

    Degenerately doped silicon nanocrystals are appealing plasmonic materials due to silicon's low cost and low toxicity. While surface plasmonic resonances of boron-doped and phosphorus-doped silicon nanocrystals were recently observed, there currently is poor understanding of the effect of surface conditions on their plasmonic behavior. Here, we demonstrate that phosphorus-doped silicon nanocrystals exhibit a plasmon resonance immediately after their synthesis but may lose their plasmonic response with oxidation. In contrast, boron-doped nanocrystals initially do not exhibit plasmonic response but become plasmonically active through postsynthesis oxidation or annealing. We interpret these results in terms of substitutional doping being the dominant doping mechanism for phosphorus-doped silicon nanocrystals, with oxidation-induced defects trapping free electrons. The behavior of boron-doped silicon nanocrystals is more consistent with a strong contribution of surface doping. Importantly, boron-doped silicon nanocrystals exhibit air-stable plasmonic behavior over periods of more than a year.

  18. Innovative boron nitride-doped propellants

    Directory of Open Access Journals (Sweden)

    Thelma Manning

    2016-04-01

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

  19. Boron Doped Graphene 3-Dimensi untuk Superkapasitor Kapasitas Tinggi

    Directory of Open Access Journals (Sweden)

    Nurlia Pramita Sari

    2017-08-01

    Full Text Available Chemical doping is an effective approach to improve the property of carbon material. In this study boron doped graphene with 3D structure used as the electrode was investigated. Boron doped graphene was prepared through freeze-dried process followed by pyrolysis of graphene oxide (GO with three types of chemical substances; boron oxide, boric acid, and boron powder in an argon and hydrogen atmosphere at 1000 C for 3 hours. The difference of chemical composition generated a different percentage of boron bond with GO. The results shows that the highest electrochemical performance was found in graphene samples with the addition of boric acid (BA 86 F/g, followed by boron oxide (BO 59.2 F/g, and boron powder (BP 2 F/g. It can be caused by boron concentration bound with graphene. The higher concentration of boron could be increased the electrochemical performance due to better of ion movement.

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

    Science.gov (United States)

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

    2016-02-02

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

  1. Doping and cluster formation in diamond

    KAUST Repository

    Schwingenschlögl, Udo

    2011-09-09

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

  2. Simulating the effect of boron doping in superconducting carbon

    Science.gov (United States)

    Sakai, Yuki; Chelikowsky, James R.; Cohen, Marvin L.

    2018-02-01

    We examine the effect of boron doping in superconducting forms of amorphous carbon. By judiciously optimizing boron substitutional sites in simulated amorphous carbon, we predict a superconducting transition temperature near 37 K at 14% boron concentration. Our findings have direct implications for understanding the recently discovered high-Tc superconductivity in Q-carbon.

  3. Energetics of Boron Doping of Carbon Pores

    Science.gov (United States)

    Wexler, Carlos; St. John, Alexander; Connolly, Matthew

    2014-03-01

    Carbon-based materials show promise, given their light weight, large surface areas and low cost for storage of hydrogen and other gases, e.g., for energy applications. Alas, the interaction of H2 and carbon, 4-5kJ/mol, is insufficient for room-temperature operation. Boron doping of carbon materials could raise the binding energy of H2 to 12-15kJ/mol. The nature of the incorporation of boron into a carbon structure has not been studied so far. In this talk we will address the energetics of boron incorporation into a carbon matrix via adsorption and decomposition of decaborane by first principles calculations. These demonstrate: (a) A strong adsorption of decaborane to carbon (70-80kJ/mol) resulting in easy incorporation of decaborane, sufficient for up to 10-20% B:C at low decaborane vapour pressures. (b) Identification that boron acts as an electron acceptor when incorporated substitutionally into a graphene-like material, as expected due to its valence. (c) The electrostatic field near the molecule is responsible for ca. 2/3 of the enhancement of the H2-adsorbent interaction in aromatic compounds such as pyrene, coronene and ovalene. Supported by DOE DE-FG36-08GO18142, ACS-PRF 52696-ND5, and NSF 1069091.

  4. Raman spectroscopy of boron-doped single-layer graphene.

    Science.gov (United States)

    Kim, Yoong Ahm; Fujisawa, Kazunori; Muramatsu, Hiroyuki; Hayashi, Takuya; Endo, Morinobu; Fujimori, Toshihiko; Kaneko, Katsumi; Terrones, Mauricio; Behrends, Jan; Eckmann, Axel; Casiraghi, Cinzia; Novoselov, Kostya S; Saito, Riichiro; Dresselhaus, Mildred S

    2012-07-24

    The introduction of foreign atoms, such as nitrogen, into the hexagonal network of an sp(2)-hybridized carbon atom monolayer has been demonstrated and constitutes an effective tool for tailoring the intrinsic properties of graphene. Here, we report that boron atoms can be efficiently substituted for carbon in graphene. Single-layer graphene substitutionally doped with boron was prepared by the mechanical exfoliation of boron-doped graphite. X-ray photoelectron spectroscopy demonstrated that the amount of substitutional boron in graphite was ~0.22 atom %. Raman spectroscopy demonstrated that the boron atoms were spaced 4.76 nm apart in single-layer graphene. The 7-fold higher intensity of the D-band when compared to the G-band was explained by the elastically scattered photoexcited electrons by boron atoms before emitting a phonon. The frequency of the G-band in single-layer substitutionally boron-doped graphene was unchanged, which could be explained by the p-type boron doping (stiffening) counteracting the tensile strain effect of the larger carbon-boron bond length (softening). Boron-doped graphene appears to be a useful tool for engineering the physical and chemical properties of graphene.

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

    Energy Technology Data Exchange (ETDEWEB)

    Keru, Godfrey; Ndungu, Patrick G.; Nyamori, Vincent O., E-mail: nyamori@ukzn.ac.za

    2015-03-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Cui Xia Yan et al

    2008-01-01

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

  7. Boron-doped nanodiamonds as possible agents for local hyperthermia

    Science.gov (United States)

    Vervald, A. M.; Burikov, S. A.; Vlasov, I. I.; Ekimov, E. A.; Shenderova, O. A.; Dolenko, T. A.

    2017-04-01

    In this work, the effective heating of surrounding water by heavily-boron-doped nanodiamonds (NDs) under laser irradiation of visible wavelength was found. Using Raman scattering spectroscopy of aqueous suspensions of boron-doped NDs, it was found that this abnormally high heating results in the weakening of hydrogen bonds much more so (2-5 times stronger) than for undoped NDs. The property of boron-doped NDs to heat a solvent under the influence of laser radiation (1-5 W cm-2) opens broad prospects for their use to create nanoagents for medical oncology and local hyperthermia.

  8. Plasmon scattering in electron and hole doped diamond

    Science.gov (United States)

    Kazempour, Ali; Morshedloo, Toktam

    2018-02-01

    By using a first principle method, we address the plasmon manipulation of diamond crystal as a function of electron and hole doped concentration ranging from light to the heavy doping regime. Our results indicate that with increasing doping concentration plasmon resonances shift to lower energies into the near ultraviolet. Further, for electron and hole doped material, bulk plasmon dispersion shows a different trend compared with undoped crystal particularly at the small momentum transfer which is attributed to strong inhomogeneity of electron charge density. Eventually, by comparison of phonon linewidths a general discussion is presented about possible mechanisms of plasmon-phonon coupling. At heavy doping regime, near the zone edge, optical phonons have the most growing contribution in bulk plasmon damping which may lead to enhanced plasmon-assisted Raman scattering for doped diamond.

  9. Iron solubility in highly boron-doped silicon

    International Nuclear Information System (INIS)

    McHugo, S.A.; McDonald, R.J.; Smith, A.R.; Hurley, D.L.; Weber, E.R.

    1998-01-01

    We have directly measured the solubility of iron in high and low boron-doped silicon using instrumental neutron activation analysis. Iron solubilities were measured at 800, 900, 1000, and 1100thinsp degree C in silicon doped with either 1.5x10 19 or 6.5x10 14 thinspboronthinspatoms/cm 3 . We have measured a greater iron solubility in high boron-doped silicon as compared to low boron-doped silicon, however, the degree of enhancement is lower than anticipated at temperatures >800thinsp degree C. The decreased enhancement is explained by a shift in the iron donor energy level towards the valence band at elevated temperatures. Based on this data, we have calculated the position of the iron donor level in the silicon band gap at elevated temperatures. We incorporate the iron energy level shift in calculations of iron solubility in silicon over a wide range of temperatures and boron-doping levels, providing a means to accurately predict iron segregation between high and low boron-doped silicon. copyright 1998 American Institute of Physics

  10. TOPICAL REVIEW: Superconductivity in CVD diamond films

    Science.gov (United States)

    Takano, Yoshihiko

    2009-06-01

    A beautiful jewel of diamond is insulator. However, boron doping can induce semiconductive, metallic and superconducting properties in diamond. When the boron concentration is tuned over 3 × 1020 cm-3, diamonds enter the metallic region and show superconductivity at low temperatures. The metal-insulator transition and superconductivity are analyzed using ARPES, XAS, NMR, IXS, transport and magnetic measurements and so on. This review elucidates the physical properties and mechanism of diamond superconductor as a special superconductivity that occurs in semiconductors.

  11. Enhanced diffusion of boron by oxygen precipitation in heavily boron-doped silicon

    Science.gov (United States)

    Torigoe, Kazuhisa; Ono, Toshiaki

    2017-06-01

    The enhanced diffusion of boron has been investigated by analyzing out-diffusion profiles in the vicinity of the interface between a lightly boron-doped silicon epitaxial layer and a heavily boron-doped silicon substrate with a resistivity of 8.2 mΩ cm and an oxide precipitate (O.P.) density of 108-1010 cm-3. It is found that the boron diffusion during annealing at 850-1000 °C is enhanced with the increase of the oxide precipitate density. On the basis of a model for boron diffusion mediated by silicon self-interstitials, we reveal that the enhanced diffusion is attributed to self-interstitials supersaturated as a result of the emission from oxide precipitates and the absorption by punched-out dislocations. In addition, the temperature dependence of the fraction of the self-interstitial emission obtained analyzing the diffusion enhancement well explains the morphology changes of oxide precipitates reported in literature.

  12. Deposition of boron doped DLC films on TiNb and characterization of their mechanical properties and blood compatibility.

    Science.gov (United States)

    Liza, Shahira; Hieda, Junko; Akasaka, Hiroki; Ohtake, Naoto; Tsutsumi, Yusuke; Nagai, Akiko; Hanawa, Takao

    2017-01-01

    Diamond-like carbon (DLC) material is used in blood contacting devices as the surface coating material because of the antithrombogenicity behavior which helps to inhibit platelet adhesion and activation. In this study, DLC films were doped with boron during pulsed plasma chemical vapor deposition (CVD) to improve the blood compatibility. The ratio of boron to carbon (B/C) was varied from 0 to 0.4 in the film by adjusting the flow rate of trimethylboron and acetylene. Tribological tests indicated that boron doping with a low B/C ratio of 0.03 is beneficial for reducing friction (μ = 0.1), lowering hardness and slightly increasing wear rate compared to undoped DLC films. The B/C ratio in the film of 0.03 and 0.4 exhibited highly hydrophilic surface owing to their high wettability and high surface energy. An in vitro platelet adhesion experiment was conducted to compare the blood compatibility of TiNb substrates before and after coating with undoped and boron doped DLC. Films with highly hydrophilic surface enhanced the blood compatibility of TiNb, and the best results were obtained for DLC with the B/C ratio of 0.03. Boron doped DLC films are promising surface coatings for blood contacting devices.

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

    Directory of Open Access Journals (Sweden)

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

    2006-01-01

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

  14. Pairwise cobalt doping of boron carbides with cobaltocene

    Science.gov (United States)

    Ignatov, A. Yu.; Losovyj, Ya. B.; Carlson, L.; LaGraffe, D.; Brand, J. I.; Dowben, P. A.

    2007-10-01

    We have performed Co K-edge x-ray absorption fine structure and x-ray absorption near edge structure measurements of Co-doped plasma enhanced chemical vapor phase deposition (PECVD) grown "C2B10Hx" semiconducting boron carbides, using cobaltocene. Cobalt does not dope PECVD grown boron carbides as a random fragment of the cobaltocene source gas. The Co atoms are fivefold boron coordinated (R=2.10±0.02Å) and are chemically bonded to the icosahedral cages of B10CHx or B9C2Hy. Pairwise Co doping occurs, with the cobalt atoms favoring sites some 5.28±0.02Å apart.

  15. Misfit accommodation mechanism at the heterointerface between diamond and cubic boron nitride.

    Science.gov (United States)

    Chen, Chunlin; Wang, Zhongchang; Kato, Takeharu; Shibata, Naoya; Taniguchi, Takashi; Ikuhara, Yuichi

    2015-02-17

    Diamond and cubic boron nitride (c-BN) are the top two hardest materials on the Earth. Clarifying how the two seemingly incompressible materials can actually join represents one of the most challenging issues in materials science. Here we apply the temperature gradient method to grow the c-BN single crystals on diamond and report a successful epitaxial growth. By transmission electron microscopy, we reveal a novel misfit accommodation mechanism for a {111} diamond/c-BN heterointerface, that is, lattice misfit can be accommodated by continuous stacking fault networks, which are connected by periodically arranged hexagonal dislocation loops. The loops are found to comprise six 60° Shockley partial dislocations. Atomically, the carbon in diamond bonds directly to boron in c-BN at the interface, which electronically induces a two-dimensional electron gas and a quasi-1D electrical conductivity. Our findings point to the existence of a novel misfit accommodation mechanism associated with the superhard materials.

  16. Electron transport in HBr adsorbed boron doped carbon nanotube

    Science.gov (United States)

    Srivastava, Reena; Shahzad Khan, Md.; Shrivastava, Sadhna; Srivastava, Anurag

    2017-01-01

    A 10,0 pristine as well as boron doped zigzag single walled carbon nanotube has been analyzed as possible HBr sensor using DFT based ab-initio approach. The variation in band structures, Mulliken charge, NBO charge, binding energy and conductance variation has been analyzed. The CNT observes a lowering of bandgap in presence of HBr molecule near its surface and reduces the metallicity of Boron doped CNT. The B-CNT shows semiconducting to metallic transition and on introducing the HBr molecule near the surface, changes its conductance drastically. Strong physisorption is observed for HBr over B-CNT surface as a consequence of electrostatic interaction.

  17. Superconductivity in CVD Diamond Thin Film Well-Above Liquid Helium Temperature

    OpenAIRE

    Takano, Y.; Nagao, M.; Kobayashi, K.; Umezawa, H.; Sakaguchi, I.; Tachiki, M.; Hatano, T.; Kawarada, H.

    2004-01-01

    Diamond has always been adored as a jewel. Even more fascinating is its outstanding physical properties; it is the hardest material known in the world with the highest thermal conductivity. Meanwhile, when we turn to its electrical properties, diamond is a rather featureless electrical insulator. However, with boron doping, it becomes a p-type semiconductor, with boron acting as a charge acceptor. Therefore the recent news of superconductivity in heavily boron-doped diamond synthesized by hig...

  18. The search for super-hard materials: doped boron

    International Nuclear Information System (INIS)

    Hebbache, M.

    2009-01-01

    Super-hard materials have numerous industrial applications and are then the subject of intense investigations. The β-rhombohedral polymorphic system of boron is the second hardest elemental crystal (H V ∼ 34 GPa). It is also very light and a p-type semiconductor. In the early seventies, it has been shown that the doping of boron with 3d transition elements enhances its hardness by about 25%. We predict that, in general, heavily doped samples MB x , with x ≤ 31 or equivalently a dopant concentration larger than 3.2 at.%, should be ultra-hard, i.e., H V > 43 GPa. The relevant dopants M are Al, Cu, Sc, Mn, Mg and Li. In addition to these properties, boron-rich materials have a very low volatility, a high chemical inertness and high melting point (> 2400 C degrees). They are suitable for applications under extreme conditions and thermoelectric equipment. (author)

  19. Potential of P-doped carbon nanocone and Si-doped boron nitride ...

    Indian Academy of Sciences (India)

    22

    The mechanisms of N2O reduction via CO on surfaces of P-doped carbon nanocone (CNC) and. Si-doped boron nitride nanocone (BNNC) by density functional theory were investigated. The adsorption energies of P and Si on surfaces of CNC and BNNC were -293.1 and -325.7 kcal/mol, respectively. The decomposition of ...

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

    International Nuclear Information System (INIS)

    Looi, H.J.

    2000-01-01

    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

  1. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-15

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

  3. Magnesium doping of boron nitride nanotubes

    Science.gov (United States)

    Legg, Robert; Jordan, Kevin

    2015-06-16

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

  4. Pressure dependence of the refractive index of diamond, cubic silicon carbide and cubic boron nitride

    Science.gov (United States)

    Balzaretti, N. M.; da Jornada, J. A. H.

    1996-09-01

    The pressure dependence of the refractive index of diamond, cubic boron nitride and cubic silicon carbide, was measured up to 9 GPa by an interferometric method using the diamond anvil cell. A least-square fit yields the following values for ( {1}/{n}) ( {dn }/{dP }): - 3.6 × 10 -4GPa -1 for diamond, -3.2 × 10 -4GPa -1 for c-BN and, for 3CSiC, -8.3 × 10 -4GPa -1. These results were used to investigate, for the first time under pressure, general empirical relationships between refractive index and energy gap found in the literature. The volume dependence of the electronic polarizability, α, of these compounds was determined through the Lorentz-Lorenz approach. The obtained linear behavior of α for the three cases was correlated to previous results for the pressure dependence of the transverse effective charge, e T∗.

  5. Electrostatic doping of graphene through ultrathin hexagonal boron nitride films.

    Science.gov (United States)

    Bokdam, Menno; Khomyakov, Petr A; Brocks, Geert; Zhong, Zhicheng; Kelly, Paul J

    2011-11-09

    When combined with graphene, hexagonal boron nitride (h-BN) is an ideal substrate and gate dielectric with which to build metal|h-BN|graphene field-effect devices. We use first-principles density functional theory (DFT) calculations for Cu|h-BN|graphene stacks to study how the graphene doping depends on the thickness of the h-BN layer and on a potential difference applied between Cu and graphene. We develop an analytical model that describes the doping very well, allowing us to identify the key parameters that govern the device behavior. A predicted intrinsic doping of graphene is particularly prominent for ultrathin h-BN layers and should be observable in experiment. It is dominated by novel interface terms that we evaluate from DFT calculations for the individual materials and for interfaces between h-BN and Cu or graphene.

  6. Voltammetric determination of sodium cyclamate in dietary products using a boron-doped diamond electrode; Determinacao voltametrica de ciclamato de sodio em produtos dieteticos empregando um eletrodo de diamante dopado com boro

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, Roberta Antigo; Carvalho, Adriana Evaristo de; Rocha-Filho, Romeu C.; Fatibello-Filho, Orlando [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica]. E-mail: bello@dq.ufscar.br

    2008-07-01

    The use of square-wave voltammetry in conjunction with a cathodic ally pre-treated diamond electrode for the analytical determination of sodium cyclamate is described. The samples were analyzed as received in a 0.5 mol L{sup -1} H{sub 2}SO{sub 4} solution in the concentration range from 5.0 x 10{sup -5} mol L{sup -1} to 4.1 x. 10{sup -4} mol L{sup -1}, with a detection limit of 4.8 x 10{sup -6} mol L{sup -1}. The RSD was smaller than 1.2 % and the proposed method was applied with success in the determination of sodium cyclamate in several dietary products. (author)

  7. Anode performance of boron-doped graphites prepared from shot and sponge cokes

    Science.gov (United States)

    Liu, Tao; Luo, Ruiying; Yoon, Seong-Ho; Mochida, Isao

    The structures and anode performances of graphitized pristine and boron-doped shot and sponge cokes have been comparatively studied by means of scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and galvanostatic measurement. The results show that high degree of graphitization can be obtained by the substituted boron atom in the carbon lattice, and boron in the resultant boron-doped graphites mainly exist in the form of boron carbide and boron substituted in the carbon lattice. Both of boron-doped graphites from shot and sponge cokes obtain discharge capacity of 350 mAh g -1 and coulombic efficiency above 90%. Apart from commonly observed discharge plateau for graphite, boron-doped samples in this study also show a small plateau at ca. 0.06 V. This phenomenon can be explained that Li ion stores in the site to be void-like spaces that are produced by "molecular bridging" between the edge sites of graphene layer stack with a release of boron atoms substituted at the edge of graphene layer. The effect of the amount of boron dopant and graphitization temperature on the anode performance of boron-doped graphite are also investigated in this paper.

  8. Structure and photoluminescence of boron and nitrogen co-doped carbon nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Wang, B.B. [College of Chemistry and Chemical Engineering, Chongqing University of Technology, 69 Hongguang Rd, Lijiatuo, Banan District, Chongqing 400054 (China); Gao, B. [College of Computer Science, Chongqing University, Chongqing 400044 (China); Chongqing Municipal Education Examinations Authority, Chongqing 401147 (China); Zhong, X.X., E-mail: xxzhong@sjtu.edu.cn [Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Shao, R.W.; Zheng, K. [Institute of Microstructure and Properties of Advanced Materials, Beijing University of Technology, Beijing 100124 (China)

    2016-07-15

    Graphical abstract: Boron- and nitrogen- doped carbon nanorods. - Highlights: • The co-doping of nitrogen and boron in carbon nanorods. • The doping mechanism of nitrogen and boron in carbon nanorods by plasma. • Photoluminescence properties of nitrogen- and boron-doped carbon nanorods. - Abstract: Boron and nitrogen doped carbon nanorods (BNCNRs) were synthesized by plasma-enhanced hot filament chemical vapor deposition, where methane, nitrogen and hydrogen were used as the reaction gases and boron carbide was the boron source. The results of scanning electron microscopy, micro-Raman spectroscopy, transmission electron microscopy and X-ray photoelectron spectroscopy indicate that boron and nitrogen can be used as co-dopants in amorphous carbon nanorods. Combined with the characterization results, the doping mechanism was studied. The mechanism is used to explain the formation of different carbon materials by different methods. The photoluminescence (PL) properties of BNCNRs were studied. The PL results show that the BNCNRs generate strong green PL bands and weak blue PL bands, and the PL intensity lowered due to the doping of boron. The outcomes advance our knowledge on the synthesis and optical properties of carbon-based nanomaterials and contribute to the development of optoelectronic nanodevices based on nano-carbon mateirals.

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

    Indian Academy of Sciences (India)

    Administrator

    Abstract. 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.

  10. 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...

  11. The corrosion resistance of zinc coatings in the presence of boron-doped detonation nanodiamonds (DND)

    Science.gov (United States)

    Burkat, G. K.; Alexandrova, G. S.; Dolmatov, V. Yu; Osmanova, E. D.; Myllymäki, V.; Vehanen, A.

    2017-02-01

    The effect of detonation nanodiamonds, doped with boron (boron-DND) in detonation synthesis on the process of zinc electrochemical deposition from zincate electrolyte is investigated. It is shown that the scattering power (coating uniformity) increases 2-4 times (depending on the concentration of DND-boron electrolyte conductivity does not change, the corrosion resistance of Zn- DND -boron coating increases 2.6 times in 3% NaCl solution (corrosion currents) and 3 times in the climatic chamber.

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

    KAUST Repository

    Mokkath, Junais Habeeb

    2014-09-04

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

  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. Boron-doped nanocrystalline silicon thin films for solar cells

    International Nuclear Information System (INIS)

    Fathi, E.; Vygranenko, Y.; Vieira, M.; Sazonov, A.

    2011-01-01

    This article reports on the structural, electronic, and optical properties of boron-doped hydrogenated nanocrystalline silicon (nc-Si:H) thin films. The films were deposited by plasma-enhanced chemical vapour deposition (PECVD) at a substrate temperature of 150 deg. C. Crystalline volume fraction and dark conductivity of the films were determined as a function of trimethylboron-to-silane flow ratio. Optical constants of doped and undoped nc-Si:H were obtained from transmission and reflection spectra. By employing p + nc-Si:H as a window layer combined with a p' a-SiC buffer layer, a-Si:H-based p-p'-i-n solar cells on ZnO:Al-coated glass substrates were fabricated. Device characteristics were obtained from current-voltage and spectral-response measurements.

  15. Employment of boron-doped carbon materials for the anode materials of lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Yu-Jin [Center for Energy Convergence, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seoul 136-791 (Korea, Republic of); Department of Energy and Environmental Engineering, University of Science and Technology (UST), 176 Gajung-dong, 217 Gajungro, Daejeon 305-350 (Korea, Republic of); Kim, Sang-Ok [Center for Energy Convergence, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seoul 136-791 (Korea, Republic of); Lee, Joong Kee, E-mail: leejk@kist.re.kr [Center for Energy Convergence, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seoul 136-791 (Korea, Republic of); Department of Energy and Environmental Engineering, University of Science and Technology (UST), 176 Gajung-dong, 217 Gajungro, Daejeon 305-350 (Korea, Republic of)

    2014-01-05

    Highlights: • Plasma carbon and boron doped carbon were formed by vapor phase synthesis using the plasma arc torch. • We investigated that graphite sheets formed as increasing content of boron using the TEM images. • We have confirmed by XRD and Raman analysis that with the increasing amount of boron, carbon increases degree graphtization. • The boron-doped carbons exhibit higher reversible capacity and better rate capability due to improved crystallinity. -- Abstract: Plasma carbon and boron-doped carbons are prepared by gas phase synthesis technique using a plasma arc torch apparatus. The effects of boron doping on the microstructure and electrochemical performance are investigated. Transmission electron microscopy results indicate that crystalline graphitic sheets are formed when the content of boron in the carbon is higher than around 1.00 wt.% X-ray diffraction (XRD) and Raman analysis also reveal that the increased amount of boron doping results in decreased interlayer spacing and increased crystallite size of the boron-doped carbons. The boron-doped carbons exhibit not only higher reversible capacity, but also better rate capability than undoped plasma carbon, due to the formation of nano-structured carbon composite composed of both spherically shaped amorphous (hard carbon-like) and paper-shaped crystalline (graphite-like) phases. The reversible capacity remained over 390 mAh g{sup −1} even after 200 cycles at a current density of 300 mA g{sup −1} for the 1.00 wt.% boron-doped carbon.

  16. 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.

  17. Characteristic Study of Boron Doped Carbon Nanowalls Films Deposited by Microwave Plasma Enhanced Chemical Vapor Deposition.

    Science.gov (United States)

    Lu, Chunyuan; Dong, Qi; Tulugan, Kelimu; Park, Yeong Min; More, Mahendra A; Kim, Jaeho; Kim, Tae Gyu

    2016-02-01

    In this research, catalyst-free vertically aligned boron doped carbon nanowalls films were fabricated on silicon (100) substrates by MPECVD using feeding gases CH4, H2 and B2H6 (diluted with H2 to 5% vol) as precursors. The substrates were pre-seeded with nanodiamond colloid. The fabricated CNWs films were characterized by Scanning Electron Microscopy (SEM) and Raman Spectroscopy. The data obtained from SEM confirms that the CNWs films have different density and wall thickness. From Raman spectrum, a G peak around 1588 cm(-1) and a D band peak at 1362 cm(-1) were observed, which indicates a successful fabrication of CNWs films. The EDX spectrum of boron doped CNWs film shows the existence of boron and carbon. Furthermore, field emission properties of boron doped carbon nanowalls films were measured and field enhancement factor was calculated using Fowler-Nordheim plot. The result indicates that boron doped CNWs films could be potential electron emitting materials.

  18. Thick homoepitaxial (110)-oriented phosphorus-doped n-type diamond

    Energy Technology Data Exchange (ETDEWEB)

    Balasubramaniam, Y.; Pobedinskas, P., E-mail: paulius.pobedinskas@uhasselt.be; Janssens, S. D.; Nesládek, M.; Haenen, K., E-mail: ken.haenen@uhasselt.be [Institute for Materials Research (IMO), Hasselt University, Wetenschapspark 1, B-3590 Diepenbeek (Belgium); IMOMEC, IMEC vzw, Wetenschapspark 1, B-3590 Diepenbeek (Belgium); Sakr, G.; Jomard, F.; Barjon, J. [Groupe d' Etude de la Matière Condensée (GEMaC), Université de Versailles St. Quentin en Yvelines, CNRS, Université Paris Saclay, 45 ave. des Etats-Unis, F-78035 Versailles (France); Turner, S.; Lu, Y.-G.; Verbeeck, J. [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Dexters, W. [Institute for Materials Research (IMO), Hasselt University, Wetenschapspark 1, B-3590 Diepenbeek (Belgium); Soltani, A. [Institut d' Electronique, Microélectronique et Nanotechnologie (IEMN/CNRS 8520), Université Lille, Ave. Poincaré-BP 60069, F-59652 Villeneuve d' Ascq (France)

    2016-08-08

    The fabrication of n-type diamond is essential for the realization of electronic components for extreme environments. We report on the growth of a 66 μm thick homoepitaxial phosphorus-doped diamond on a (110)-oriented diamond substrate, grown at a very high deposition rate of 33 μm h{sup −1}. A pristine diamond lattice is observed by high resolution transmission electron microscopy, which indicates the growth of high quality diamond. About 2.9 × 10{sup 16} cm{sup −3} phosphorus atoms are electrically active as substitutional donors, which is 60% of all incorporated dopant atoms. These results indicate that P-doped (110)-oriented diamond films deposited at high growth rates are promising candidates for future use in high-power electronic applications.

  19. Potential of P-doped carbon nanocone and Si-doped boron nitride ...

    Indian Academy of Sciences (India)

    22

    Si-doped boron nitride nanocone (BNNC) by density functional theory were investigated. The adsorption energies of P and Si on surfaces of CNC and BNNC were -293.1 and -325.7 kcal/mol, respectively. The decomposition of CNC-P-N2O and BNNC-Si-N2O and reduction of CNC-P-. O* and BNNC-Si-O* by CO molecule ...

  20. n-type diamond growth by phosphorus doping on (0 0 1)-oriented surface

    International Nuclear Information System (INIS)

    Kato, Hiromitsu; Makino, Toshiharu; Yamasaki, Satoshi; Okushi, Hideyo

    2007-01-01

    The properties of phosphorus incorporation for n-type doping of diamond are discussed and summarized. Doping of (0 0 1)-oriented diamond is introduced and compared with results achieved on (1 1 1) diamond. This review describes detailed procedures and conditions of plasma-enhanced chemical vapour deposition (CVD) growth and characteristics of electrical properties of phosphorus-doped diamond. The phosphorus incorporation was characterized by SIMS analysis including mapping. n-type conductivity is evaluated by Hall-effect measurements over a temperature regime of 300-1000 K. The crystal perfection of (0 0 1)-oriented n-type diamond is also evaluated by x-ray diffraction, Raman spectroscopy, reflection high-energy electron diffraction and cathodoluminescence analyses. The results show that phosphorus atoms are incorporated into the diamond network during (0 0 1) CVD diamond growth and that phosphorus acts as a donor as in (1 1 1)-oriented diamond. This result eliminates the restriction on substrate orientation, which had previously created a bottleneck in the development of diamond electronic devices. (review article)

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

    International Nuclear Information System (INIS)

    Kirihara, K.; Hyodo, H.; Fujihisa, H.; Wang, Z.; Kawaguchi, K.; Shimizu, Y.; Sasaki, T.; Koshizaki, N.; Soga, K.; Kimura, K.

    2006-01-01

    We measured electrical conductance of single crystalline boron nanobelts having α-tetragonal crystalline structure. The doping experiment of Mg was carried out by vapor diffusion method. The pure boron nanobelt is a p-type semiconductor and its electrical conductivity was estimated to be on the order of 10 -3 (Ω cm) -1 at room temperature. The carrier mobility of pure boron nanobelt was measured to be on the order of 10 -3 (cm 2 Vs -1 ) at room temperature and has an activation energy of ∼0.19 eV. The Mg-doped boron nanobelts have the same α-tetragonal crystalline structure as the pristine nanobelts. After Mg vapor diffusion, the nanobelts were still semiconductor, while the electrical conductance increased by a factor of 100-500. Transition to metal or superconductor by doping was not observed. - Graphical abstract: SEM micrographs of boron nanobelt after Ni/Au electrode fabrication by electron beam lithography. Display Omitted

  2. Hole states in diamond p-delta-doped field effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Orozco, J C; Rodriguez-Vargas, I [Unidad Academica de Fisica, Universidad Autonoma de Zacatecas, Calzada Solidaridad Esquina con Paseo la Bufa S/N, CP 98060 Zacatecas, ZAC. (Mexico); Mora-Ramos, M E, E-mail: jcmover@correo.unam.m [Facultad de Ciencias, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, CP 62209 Cuernavaca, MOR. (Mexico)

    2009-05-01

    The p-delta-doping in diamond allows to create high density two-dimensional hole gases. This technique has already been applied in the design and fabrication of diamond-based field effect transistors. Consequently, the knowledge of the electronic structure is of significant importance to understand the transport properties of diamond p-delta-doped systems. In this work the hole subbands of diamond p-type delta-doped quantum wells are studied within the framework of a local-density Thomas-Fermi-based approach for the band bending profile. The calculation incorporates an independent three-hole-band scheme and considers the effects of the contact potential, the delta-channel to contact distance, and the ionized impurity density.

  3. Effect of low level doping of boron and phosphorus on the properties of amorphous silicon films

    International Nuclear Information System (INIS)

    Tran, N.T.; Epstein, K.A.; Grimmer, D.P.; Vernstrom, G.D.

    1987-01-01

    Effect of the low level doping of boron and phosphorus on the properties of amorphous silicon films (a-Si:H) were studied. Doping level of both boron and phosphorus was in the range of 10/sup 17/ atoms/cm/sup 3/. Apparent improvement in the stability of dark and photoconductivity of a-Si: films upon low level doping does not result from the elimination of light-induced defects. The stability of the dark and photoconductivity upon doping is an indication of pinning of the Fermi level

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

    DEFF Research Database (Denmark)

    Ou, Yiyu; Jokubavicius, Valdas; Liu, Chuan

    2011-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Darwish, Ahmed A. [Center for Nanotechnology, Zewail City of Science and Technology, Giza 12588 (Egypt); Department of Nuclear and Radiation Engineering, Faculty of Engineering, Alexandria University, Alexandria (Egypt); Fadlallah, Mohamed M. [Center for Fundamental Physics, Zewail City of Science and Technology, Giza 12588 (Egypt); Department of Physics, Faculty of Science, Benha University, Benha (Egypt); Badawi, Ashraf [Center for Nanotechnology, Zewail City of Science and Technology, Giza 12588 (Egypt); Maarouf, Ahmed A., E-mail: ahmed.maarouf@egnc.gov.eg [Center for Fundamental Physics, Zewail City of Science and Technology, Giza 12588 (Egypt); Egypt Nanotechnology Center & Department of Physics, Faculty of Science, Cairo University, Giza 12613 (Egypt)

    2016-07-30

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

  6. Gold intercalation of boron-doped graphene on Ni(111): XPS and DFT study.

    Science.gov (United States)

    Zhao, W; Gebhardt, J; Gotterbarm, K; Höfert, O; Gleichweit, C; Papp, C; Görling, A; Steinrück, H-P

    2013-11-06

    The intercalation of a graphene layer adsorbed on a metal surface by gold or other metals is a standard procedure. While it was previously shown that pristine, i.e., undoped, and nitrogen-doped graphene sheets can be decoupled from a nickel substrate by intercalation with gold atoms in order to produce quasi-free-standing graphene, we find the gold intercalation behavior for boron-doped graphene on a Ni(111) surface to be more complex: for low boron contents (2-5%) in the graphene lattice only partial gold intercalation occurs and for higher boron contents (up to 20%) no intercalation is observed. In order to understand this different behavior, a density functional theory investigation is carried out, comparing undoped as well as substitutional nitrogen- and boron-doped graphene on Ni(111). We identify the stronger binding of the boron atoms to the nickel substrate as the factor responsible for the different intercalation behavior in the case of boron doping. However, the calculations predict that this energetic effect prevents the intercalation process only for large boron concentrations and that it can be overcome for smaller boron coverages, in line with our x-ray photoelectron spectroscopy experiments.

  7. Characterization and photocatalytic activity of boron-doped TiO2 thin ...

    Indian Academy of Sciences (India)

    Wintec

    Department of Physics, Sri Venkateswara University, Tirupati 517 502, India. MS received 28 December 2007; revised 16 March 2008. Abstract. 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 ...

  8. 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)

  9. High temperature surface Brillouin scattering study of mechanical properties of boron-doped epitaxial polysilicon

    Directory of Open Access Journals (Sweden)

    B. A. Mathe

    2017-02-01

    Full Text Available A study of the mechanical properties of a boron-doped epitaxial polysilicon layer deposited on a Si (100 substrate specimen has been carried out by surface Brillouin scattering at high temperatures. This type of specimen is widely used in micro-electro-mechanical systems (MEMS. By accumulating spectra with the Rayleigh mode and the Lamb continuum the isotropic elastic constants C44 and C11 were obtained, from which the values of the bulk, shear and Young’s moduli and Poisson’s ratio for the layer were determined over a range of temperatures from 20 °C to 110 °C. By contrast, an examination of the literature on polycrystalline silicon shows that other methods each provide a limited range of the above properties and thus additional experiments and techniques were needed. The SBS method is applicable to other polycrystalline materials such as silicon carbide, silicon nitride, silicon germanium and amorphous diamond that have also been used for MEMS applications.

  10. First principle investigations on Boron doped Fe2VAl Heusler alloy

    International Nuclear Information System (INIS)

    Venkatesh, Ch.; Srivastava, S.K.; Rao, V.V.

    2014-01-01

    The role of atomic size of sp-element is investigated through theoretical calculations and basic experiments to understand the physical properties of Boron doped Fe 2 VAl alloy. The results of ab-initio calculations on ordered L2 1 structure of Fe 2 VAl 1-x B x (x=0, 0.5, 1) alloys have been compared to understand the role of sp-element size on the hybridization among their respective valance states. Interestingly, semi-metallic and paramagnetic like ground states were found in the Boron doped alloys in similar to Fe 2 VAl, eliminating the role of size of the doppent sp-atom. These calculations result in hybridization where the covalent distribution of valance states among the atoms is responsible to produce a finite pseudo-gap at the Fermi level. The observed features could be explained on the basis of covalent theory of magnetism in which an amount of spectral weight transfer occurs in the DOS spectrum among the same spin orbitals, leading to symmetric distribution of bonding and anti-bonding states. However, the obtained experimental findings on Boron doped alloys are in contrast with these calculations, indicating that experimentally the alloy formation into an ideal L2 1 lattice does not happen while doping with Boron. Further, the micro structural analysis shows Boron segregation across the grain boundaries that may form magnetic inhomogeneities in the lattice of Boron doped Fe 2 VAl alloys which preferably cause these experimental anomalies

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

    Indian Academy of Sciences (India)

    Administrator

    report on the synthesis of boron-doped manganese telluride (B-doped MnTe) semiconductor-decorated .... research on this issue represents a stage in the improve- ment to produce higher power conversion efficiency ... sart University, Kamphaeng Saen Campus, for financial support and thanks to the Kasetsart University ...

  12. Modified diamond electrodes for electrolysis and electroanalysis applications

    International Nuclear Information System (INIS)

    Einaga, Yasuaki; Sato, Rika; Olivia, Herlambang; Shin, Dongchan; Ivandini, T.A.; Fujishima, Akira

    2004-01-01

    The outstanding properties of diamond make it a very attractive material for use in many potential applications. In particular, the superior electrochemical properties of highly boron-doped conductive diamond films, prepared by the chemical vapor deposition (CVD) process, have received attention from electrochemists. This paper reports several diversified applications of boron-doped diamond electrodes; highly sensitive and interference-free microfiber electrodes with over-oxidized polypyrrole modification, integrated electrochemical detector for microchip capillary electrophoresis (CE), and smoothing treatments of micro-polycrystalline surface. Studies have been made of the electrochemical properties of each system and their application in electroanalysis is discussed

  13. Tl and OSL dosimetry of diamond films CVD pure and unpurified with boron-carbon

    International Nuclear Information System (INIS)

    Melendrez, R.; Pedroza M, M.; Chernov, V.; Ochoa N, J.D.; Bernal, R.; Barboza F, M.; Castaneda, B.; Goncalves, J.A.N.; Sandonato, G.M.; Cruz Z, E.; Preciado F, S.; Cruz V, C.; Brown, F.; Schreck, M.

    2004-01-01

    The diamond is a material that possesses extreme physical properties, such as its hardness to the radiation, its low chemical reactivity besides its equivalence to the human tissue, which qualify him as an ideal material for radiation dosimetry. In this work, it was studied the thermal and optically stimulated response (Tl and OSL) of polycrystalline diamond films grown by the technique of CVD pure and contaminated with Boron-carbon (B/C) with the intention of characterizing their efficiency like a dosemeter for radiation in a range of 0 - 3000 Gy. For the case of the films without impurities, the Tl curve presents four main peaks, two of them in an interval of temperatures of 150-200 C and other two additional around of 250-400 C. The dependence of the response of integrated Tl and that of OSL always maintained a lineal relationship with the exhibition dose up to 100 Gy. The behavior of the films contaminated with B/C (2000 - 20000 ppm) was established through experiments that involved the signal of OSL and their relationship with the Tl response. It was found that this processes are correlated, since the electrons caught in the traps of low temperature (50 - 250 C) of the Tl they are the electrons that recombining with more probability to provide the signal of OSL. According to these results it is possible to propose the diamond films as a good candidate for dosimetry to, using the traditional technique of Tl so much as well as the but recent of OSL. (Author)

  14. Measurements of Increased Enthalpies of Adsorption for Boron-Doped Activated Carbons

    Science.gov (United States)

    Gillespie, Andrew; Beckner, Matthew; Chada, Nagaraju; Schaeperkoetter, Joseph; Singh, Anupam; Lee, Mark; Wexler, Carlos; Burress, Jacob; Pfeifer, Peter

    2013-03-01

    Boron-doping of activated carbons has been shown to increase the enthalpies of adsorption for hydrogen as compared to their respective undoped precursors (>10kJ/mol compared to ca. 5kJ/mol). This has brought significant interest to boron-doped carbons for their potential to improve hydrogen storage. Boron-doped activated carbons have been produced using a process involving the deposition of decaborane (B10H14) and high-temperature annealing resulting in boron contents up to 15%. In this talk, we will present a systematic study of the effect that boron content has on the samples' structure, hydrogen sorption, and surface chemistry. Measurements have shown a significant increase in the areal hydrogen excess adsorption and binding energy. Experimental enthalpies of adsorption will be presented for comparison to theoretical predictions. Additionally, samples have been characterized by thermal gravimetric analysis, gas chromatography-mass spectroscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. TGA and GC-MS results investigated the decomposition of the decaborane in the carbon. Boron-carbon bonds are shown in the FTIR and XPS spectra, indicating that boron has been incorporated into the carbon matrix. Work supported by DOE-EERE, Award No. DE-FG36-08GO18142

  15. Low-temperature electrical transport in B-doped ultrananocrystalline diamond film

    International Nuclear Information System (INIS)

    Li, Lin; Zhao, Jing; Hu, Zhaosheng; Quan, Baogang; Li, Junjie; Gu, Changzhi

    2014-01-01

    B-doped ultrananocrystalline diamond (UNCD) films are grown using hot-filament chemical vapor deposition method, and their electrical transport properties varying with temperature are investigated. When the B-doped concentration of UNCD film is low, a step-like increase feature of the resistance is observed with decreasing temperature, reflecting at least three temperature-modified electronic state densities at the Fermi level according to three-dimensional Mott's variable range hopping transport mechanism, which is very different from that of reported B-doped nanodiamond. With increasing B-doped concentration, a superconductive transformation occurs in the UNCD film and the highest transformation temperature of 5.3 K is observed, which is higher than that reported for superconducting nanodiamond films. In addition, the superconducting coherence length is about 0.63 nm, which breaks a reported theoretical and experimental prediction about ultra-nanoscale diamond's superconductivity

  16. Photocatalytic activity of TiO2 doped with boron and vanadium

    International Nuclear Information System (INIS)

    Bettinelli, M.; Dallacasa, V.; Falcomer, D.; Fornasiero, P.; Gombac, V.; Montini, T.; Romano, L.; Speghini, A.

    2007-01-01

    Boron (B)- and vanadium (V)-doped TiO 2 photocatalysts were synthesized using modified sol-gel reaction processes and characterized by X-ray diffraction (XRD), Raman spectroscopy and N 2 physisorption (BET). The photocatalytic activities were evaluated by monitoring the degradation of methylene blue (MB). The results showed that the materials possess high surface area. The addition of B favored the transformation of anatase to rutile, while in the presence of V, anatase was the only phase detected. The MB degradation on V-doped TiO 2 was significantly affected by the preparation method. In fact while the presence of V in the bulk did not influence strongly the photoreactivity under visible irradiation, an increase of surface V doping lead to improved photodegradation of MB. The degradation of MB dye indicated that the photocatalytic activities of TiO 2 increased as the boron doping increased, with high conversion efficiency for 9 mol% B doping

  17. Silicon doped boron carbide nanorod growth via a solid-liquid-solid process

    Science.gov (United States)

    Han, Wei-Qiang

    2006-03-01

    Here we report the synthesis of silicon doped boron carbide (Si-doped B4C) nanorods via a solid reaction using activated carbon, boron, and silicon powder as reactants. These nanorods have been studied by high-resolution transmission electron microscopy, scanning electron microscopy, electron energy loss spectroscopy, and energy-dispersive x-ray spectrometry. The diameter of Si-doped B4C nanorods ranges from 15to70nm. The length of Si-doped B4C nanorods is up to 30μm. NixCoyBz nanoparticles are used as catalysts for the growth of Si-doped B4C nanorods. A solid-liquid-solid growth mechanism is proposed.

  18. Diffuse X-ray scattering from neutron-irradiated silicon doped with boron

    International Nuclear Information System (INIS)

    Mayer, W.; Grasse, D.; Peisl, J.

    1985-01-01

    The diffuse X-ray scattering and lattice parameter change of silicon crystals heavily doped with boron after electron and neutron irradiation are measured. From a comparison of unirradiated and electron-irradiated samples the volume change is determined of substitutional boron Q/sub B/ = -(2.2 +- 0.2) x 10 -2 nm 3 and of boron with a trapped interstitial Q/sub BI/ = (0 +- 0.5) x 10 -2 nm 3 . During neutron irradiation of the doped samples each boron stabilizes an additional Frenkel pair by trapping of the interstitial. The concentration of the untrapped interstitials remains the same as in the undoped sample, but the nucleation of interstitial clusters is enhanced thus reducing the cluster size to 93% of the value of undoped samples. (author)

  19. n-Type phosphorus-doped nanocrystalline diamond: electrochemical and in situ Raman spectroelectrochemical study

    OpenAIRE

    Zivcova, Z. Vlckova; Frank, O.; Drijkoningen, Sien; Haenen, Ken; Mortet, Vincent; Kavan, L.

    2016-01-01

    Electrochemical and in situ Raman spectroelectrochemical characterization of n-type phosphorus-doped nanocrystalline diamond (P-NCD) is carried out. The P-NCD films are grown by microwave plasma enhanced chemical vapour deposition and doped with phosphorus at a concentration of 10 000 ppm in the gas phase. Micro-Raman spectroscopy determines the film quality (presence of graphitic or amorphous phases). All electrochemical measurements are performed in aqueous 0.5 M H2SO4 electrolyte solution....

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

    International Nuclear Information System (INIS)

    Trócoli, Rafael; Franger, Sylvain; Cruz, Manuel; Morales, Julián; Santos-Peña, Jesús

    2014-01-01

    Highlights: • Thermal treatment of boron phosphate with LiFePO 4 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 LiFePO 4 , FePO 4 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 BPO 4 in 3-9% weight at 700 °C. The materials can be described as nanocomposites containing i) LiFePO 4 , possibly doped with a low amount of boron, ii) FePO 4 and iii) an amorphous layer based on Li 4 P 2 O 7 -derived material that surrounds the phosphate particles. The thermal treatment with BPO 4 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 B 6 -LiFePO 4 , 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

  1. Facile Fabrication of Boron-Doped Titania Nanopowders by Atmospheric Pressure Chemical Vapor Synthesis Route and its Photocatalytic Activity

    Directory of Open Access Journals (Sweden)

    K. Saberyan

    2014-04-01

    Full Text Available The Atmospheric Pressure Chemical Vapor Synthesis (APCVS route is a process that can be used for the synthesis of doped-nanocrystalline powders with very small crystallite sizes having a narrow particle size distribution and high purity. In this study, APCVS technique was used to prepare boron-doped titania nanopowders. The effects of temperature, borate flow rate and water flow rate on the amount of doped boron were studied. The resultant powders were characterized by inductively coupled plasma (ICP, X-ray diffraction (XRD, nitrogen adsorption technique (BET, UV-visible DRS spectroscopy, scanning electron microscopy (SEM, and transmission electron microscopy (TEM. The optimum boron precursor flow rate was 80 sccm. The highest amount of doped boron was attained when water flow rate was 900 sccm. In comparison to the pristine TiO2, the boron-doped TiO2 nanoparticles showed blue-shift in band-gap energy of the samples.

  2. Analysis of hydrogen sorption characteristics of boron-doped activated carbons

    Science.gov (United States)

    Beckner, M.; Romanos, J.; Stalla, D.; Dohnke, E.; Singh, A.; Lee, M.; Suppes, G.; Hawthorne, M. F.; Yu, P.; Wexler, C.; Pfeifer, P.

    2011-03-01

    There is significant interest in the properties of boron-doped activated carbons for their potential to improve hydrogen storage. Boron-doped activated carbons have been produced using a novel process involving the pyrolysis of a boron containing compound and subsequent high-temperature annealing. In this talk we will present a systematic study of the effect of different boron doping processes on the samples' surface area, micropore structure, and hydrogen sorption. Experimental results include boron content from prompt gamma neutron activation analysis, boron-carbon chemistry from Fourier transform infrared spectroscopy (FTIR), nitrogen subcritical adsorption, and 80K and 90K hydrogen adsorption isotherms which allow us to evaluate the hydrogen binding energy for each sorptive material. This material is based on work supported by the US Department of Defense under Awards No. N00164-07-P-1306 and N00164-08-C-GS37, the US Department of Energy under Awards No. DE-FG02-07ER46411 and DE-FG36-08GO18142.

  3. Boron, phosphorus, and gallium determination in silicon crystals doped with gallium

    International Nuclear Information System (INIS)

    Shklyar, B.L.; Dankovskij, Yu.V.; Trubitsyn, Yu.V.

    1989-01-01

    When studying IR transmission spectra of silicon doped with gallium in the range of concentrations 1 x 10 14 - 5 x 10 16 cm -3 , the possibility to quantity at low (∼ 20 K) temperatures residual impurities of boron and phosphorus is ascertained. The lower determination limit of boron is 1 x 10 12 cm -3 for a sample of 10 nm thick. The level of the impurities in silicon crystals, grown by the Czochralski method and method of crucible-free zone melting, is measured. Values of boron and phosphorus concentrations prior to and after their alloying with gallium are compared

  4. Atomistic boron-doped graphene field-effect transistors: a route toward unipolar characteristics.

    Science.gov (United States)

    Marconcini, Paolo; Cresti, Alessandro; Triozon, François; Fiori, Gianluca; Biel, Blanca; Niquet, Yann-Michel; Macucci, Massimo; Roche, Stephan

    2012-09-25

    We report fully quantum simulations of realistic models of boron-doped graphene-based field-effect transistors, including atomistic details based on DFT calculations. We show that the self-consistent solution of the three-dimensional (3D) Poisson and Schrödinger equations with a representation in terms of a tight-binding Hamiltonian manages to accurately reproduce the DFT results for an isolated boron-doped graphene nanoribbon. Using a 3D Poisson/Schrödinger solver within the non-equilibrium Green's function (NEGF) formalism, self-consistent calculations of the gate-screened scattering potentials induced by the boron impurities have been performed, allowing the theoretical exploration of the tunability of transistor characteristics. The boron-doped graphene transistors are found to approach unipolar behavior as the boron concentration is increased and, by tuning the density of chemical dopants, the electron-hole transport asymmetry can be finely adjusted. Correspondingly, the onset of a mobility gap in the device is observed. Although the computed asymmetries are not sufficient to warrant proper device operation, our results represent an initial step in the direction of improved transfer characteristics and, in particular, the developed simulation strategy is a powerful new tool for modeling doped graphene nanostructures.

  5. Cobalt Doping of Semiconducting Boron Carbide Using Cobaltocene

    National Research Council Canada - National Science Library

    Carlson, Lonnie

    2007-01-01

    .... This temperature dependent surface photovoltage effect is not compelling evidence for the majority carrier type but does suggest an increase in the carrier concentration in semiconducting boron...

  6. Photoluminescence and Raman Spectroscopy Characterization of Boron- and Nitrogen-Doped 6H Silicon Carbide

    DEFF Research Database (Denmark)

    Ou, Yiyu; Jokubavicius, Valdas; Liu, Chuan

    2012-01-01

    Nitrogen-boron doped 6H-SiC epilayers grown on low off-axis 6H-SiC substrates have been characterized by photoluminescence and Raman spectroscopy. The photoluminescence results show that a doping larger than 1018 cm-3 is favorable to observe the luminescence and addition of nitrogen is resulting...... in an increased luminescence. A dopant concentration difference larger than 4x1018 cm-3 is proposed to achieve intense photoluminescence. Raman spectroscopy further confirmed the doping type and concentrations for the samples. The results indicate that N-B doped SiC is being a good wavelength converter in white...

  7. Enhancing the mechanical properties of single-crystal CVD diamond.

    Science.gov (United States)

    Liang, Qi; Yan, Chih-Shiue; Meng, Yufei; Lai, Joseph; Krasnicki, Szczesny; Mao, Ho-Kwang; Hemley, Russell J

    2009-09-09

    Approaches for enhancing the strength and toughness of single-crystal diamond produced by chemical vapor deposition (CVD) at high growth rates are described. CVD processes used to grow single-crystal diamond in high density plasmas were modified to incorporate boron and nitrogen. Semi-quantitative studies of mechanical properties were carried out using Vickers indentation techniques. The introduction of boron in single-crystal CVD diamond can significantly enhance the fracture toughness of this material without sacrificing its high hardness (∼78 GPa). Growth conditions were varied to investigate its effect on boron incorporation and optical properties by means of photoluminescence, infrared, and ultraviolet-visible absorption spectroscopy. Boron can be readily incorporated into single-crystal diamond by the methods used, but with nitrogen addition, the incorporation of boron was hindered. The spectroscopic measurements indicate that nitrogen and boron coexist in the diamond structure, which helps explain the origin of the enhanced fracture toughness of this material. Further, low pressure/high temperature annealing can enhance the intrinsic hardness of single-crystal CVD diamond by a factor of two without appreciable loss in fracture toughness. This doping and post-growth treatment of diamond may lead to new technological applications that require enhanced mechanical properties of diamond.

  8. 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

  9. Electrochemical applications of CVD diamond

    International Nuclear Information System (INIS)

    Pastor-Moreno, Gustavo

    2002-01-01

    Diamond technology has claimed an important role in industry since non-expensive methods of synthesis such as chemical vapour deposition allow to elaborate cheap polycrystalline diamond. This fact has increased the interest in the scientific community due to the outstanding properties of diamond. Since Pleskov published in 1987 the first paper in electrochemistry, many researchers around the world have studied different aspects of diamond electrochemistry such as reactivity, electrical structure, etc. As part of this worldwide interest these studies reveal new information about diamond electrodes. These studies report investigation of diamond electrodes characterized using structural techniques like scanning electrode microscopy and Raman spectroscopy. A new electrochemical theory based on surface states is presented that explains the metal and the semiconductor behaviour in terms of the doping level of the diamond electrode. In an effort to characterise the properties of diamond electrodes the band edges for hydrogen and oxygen terminated surface are located in organic solvent, hence avoiding possible interference that are present in aqueous solution. The determination of the band edges is performed by Mott-Schottky studies. These allow the calculation of the flat band potential and therefore the band edges. Additional cyclic voltammetric studies are presented for both types of surface termination. Mott-Schottky data and cyclic voltammograms are compared and explained in terms of the band edge localisation. Non-degenerately p-type semiconductor behaviour is presented for hydrogen terminated boron doped diamond. Graphitic surface states on oxidised surface boron doped diamond are responsible for the electrochemistry of redox couples that posses similar energy. Using the simple redox couple 1,4-benzoquinone effect of surface termination on the chemical behaviour of diamond is presented. Hydrogen sublayers in diamond electrodes seem to play an important role for the

  10. Comparative investigation of surface transfer doping of hydrogen terminated diamond by high electron affinity insulators

    Energy Technology Data Exchange (ETDEWEB)

    Verona, C.; Marinelli, Marco; Verona-Rinati, G. [Dip. di Ingegneria Industriale, Università di Roma “Tor Vergata,” Via del Politecnico 1, I-00133 Roma (Italy); Ciccognani, W.; Colangeli, S.; Limiti, E. [Dip. di Ingegneria Elettronica, Università di Roma “Tor Vergata,” Via del Politecnico 1, I-00133 Roma (Italy)

    2016-07-14

    We report on a comparative study of transfer doping of hydrogenated single crystal diamond surface by insulators featured by high electron affinity, such as Nb{sub 2}O{sub 5}, WO{sub 3}, V{sub 2}O{sub 5}, and MoO{sub 3}. The low electron affinity Al{sub 2}O{sub 3} was also investigated for comparison. Hole transport properties were evaluated in the passivated hydrogenated diamond films by Hall effect measurements, and were compared to un-passivated diamond films (air-induced doping). A drastic improvement was observed in passivated samples in terms of conductivity, stability with time, and resistance to high temperatures. The efficiency of the investigated insulators, as electron accepting materials in hydrogenated diamond surface, is consistent with their electronic structure. These surface acceptor materials generate a higher hole sheet concentration, up to 6.5 × 10{sup 13} cm{sup −2}, and a lower sheet resistance, down to 2.6 kΩ/sq, in comparison to the atmosphere-induced values of about 1 × 10{sup 13} cm{sup −2} and 10 kΩ/sq, respectively. On the other hand, hole mobilities were reduced by using high electron affinity insulator dopants. Hole mobility as a function of hole concentration in a hydrogenated diamond layer was also investigated, showing a well-defined monotonically decreasing trend.

  11. First Principles Atomistic Model for Carbon-Doped Boron Suboxide

    Science.gov (United States)

    2014-09-01

    Sutherland DG, Van Buuren T, Carlisle JA, Terminello LJ, Himpsel FJ. Photoemission and x - ray -absorption study of boron carbide and its surface thermal...along the C-C chain. If the interstitial dopant is either B or C, a local boron carbide (B4C)-like structure with either a C-B-C or C-C-C chain is...strength, high oxidation resistance (򒱰 °C), and chemical inertness.1–8 However, unlike other high-performance ceramics, boron carbide (B4C) and

  12. Improved Thermal Performance of Diamond-Copper Composites with Boron Carbide Coating

    Science.gov (United States)

    Hu, Haibo; Kong, Jian

    2013-11-01

    B4C-coated diamond (diamond@B4C) particles are used to improve the interfacial bonding and thermal properties of diamond/Cu composites. Scanning electron microscopy, x-ray diffraction, and x-ray photoelectron spectroscopy were applied to characterize the formed B4C coating on diamond particles. It is found that the B4C coating strongly improves the interfacial bonding between the Cu matrix and diamond particles. The resulting diamond@B4C/Cu composites show high thermal conductivity of 665 W/mK and low coefficient of thermal expansion of 7.5 × 10-6/K at 60% diamond volume fraction, which are significantly superior to those of the composites with uncoated diamond particles. The experimental thermal conductivity is also theoretically analyzed to account for the thermal resistance at the diamond@B4C-Cu interface boundary.

  13. Characterization and photocatalytic activity of boron-doped TiO2 thin ...

    Indian Academy of Sciences (India)

    Wintec

    was found that chlorobenzene undergoes degradation efficiently in presence of boron doped TiO2 thin films by exposing its aqueous solution to ... at different irradiation times. The solution was bubbled frequently with air during irradiation. ... X-ray diffraction spectra were obtained from an X-ray diffractometer (type PW 3710 ...

  14. The atomic and electronic structure of nitrogen- and boron-doped phosphorene.

    Science.gov (United States)

    Boukhvalov, Danil W

    2015-10-28

    First principles modeling of nitrogen- and boron-doped phosphorene demonstrates the tendency toward the formation of highly ordered structures. Nitrogen doping leads to the formation of -N-P-P-P-N- lines. Further transformation into -P-N-P-N- lines across the chains of phosphorene occurs with increasing band gap and increasing nitrogen concentration, which coincides with the decreasing chemical activity of N-doped phosphorene. In contrast to the case of nitrogen, boron atoms prefer to form -B-B- pairs with the further formation of -P-P-B-B-P-P- patterns along the phosphorene chains. The low concentration of boron dopants converts the phosphorene from a semiconductor into a semimetal with the simultaneous enhancement of its chemical activity. Co-doping of phosphorene by both boron and nitrogen starts from the formation of -B-N- pairs, which provides flat bands and further transformation of these pairs into hexagonal BN lines and ribbons across the phosphorene chains.

  15. Low-temperature phenomena in highly doped grained diamond

    Czech Academy of Sciences Publication Activity Database

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

    2009-01-01

    Roč. 9, č. 6 (2009), s. 3689-3694 ISSN 1533-4880 Institutional research plan: CEZ:AV0Z10100521 Keywords : nanocrystalline diamond films * granular structure * superconductivity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.435, year: 2009

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-06-23

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

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

    International Nuclear Information System (INIS)

    Yang, Y.T.; Ding, R.X.; Song, J.X.

    2011-01-01

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

  18. Structural, electronic and magnetic properties of carbon doped boron nitride nanowire: Ab initio study

    Energy Technology Data Exchange (ETDEWEB)

    Jalilian, Jaafar, E-mail: JaafarJalilian@gmail.com [Young Researchers and Elite Club, Kermanshah Br anch, Islamic Azad University, P.O. Box: 6718997551, Kermanshah (Iran, Islamic Republic of); Kanjouri, Faramarz, E-mail: kanjouri@khu.ac.ir [Physics Department, Faculty of Science, Kharazmi University, University Square, P.O. Box: 3197937551, Karaj (Iran, Islamic Republic of)

    2016-11-15

    Using spin-polarized density functional theory calculations, we demonstrated that carbon doped boron nitride nanowire (C-doped BNNW) has diverse electronic and magnetic properties depending on position of carbon atoms and their percentages. Our results show that only when one carbon atom is situated on the edge of the nanowire, C-doped BNNW is transformed into half-metal. The calculated electronic structure of the C-doped BNNW suggests that doping carbon can induce localized edge states around the Fermi level, and the interaction among localized edge states leads to semiconductor to half-metal transition. Overall, the bond reconstruction causes of appearance of different electronic behavior such as semiconducting, half-metallicity, nonmagnetic metallic, and ferromagnetic metallic characters. The formation energy of the system shows that when a C atom is doped on surface boron site, system is more stable than the other positions of carbon impurity. Our calculations show that C-doped BNNW may offer unique opportunities for developing nanoscale spintronic materials.

  19. Ab initio self-consistent calculations of the Compton profiles and polarizabilities of diamond and cubic boron nitride

    CERN Document Server

    Ayma, D; Lichanot, A

    1998-01-01

    Compton profiles, polarizabilities and related functions of diamond and cubic boron nitride have been investigated within the Hartree-Fock approximation and the density functional theory, calculated within the local density approximation and generalized gradient approximation, but without any explicit correlation correction for the Compton profiles. The correlation part already included in the standard uncorrected density functional theory is deduced from the comparison of the two types of calculation. The Compton profile and reciprocal-form-factor anisotropies, polarizability, dielectric constant and energy loss function of the two compounds are compared at the same level of accuracy. These properties are very close in spite of the rather different chemical bonds due to the charge transfer occurring in cubic boron nitride and gaps. (author)

  20. Effect of sintering temperature and boron carbide content on the wear behavior of hot pressed diamond cutting segments

    OpenAIRE

    Islak S.; Çelik H.

    2015-01-01

    The aim of this study was to investigate the effect of sintering temperature and boron carbide content on wear behavior of diamond cutting segments. For this purpose, the segments contained 2, 5 and 10 wt.% B4C were prepared by hot pressing process carried out under a pressure of 35 MPa, at 600, 650 and 700 °C for 3 minutes. The transverse rupture strength (TRS) of the segments was assessed using a three-point bending test. Ankara andesite stone was cut to ...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-11-01

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

  2. Electrical current at micro-/macro-scale of undoped and nitrogen-doped MWPECVD diamond films

    Science.gov (United States)

    Cicala, G.; Velardi, L.; Senesi, G. S.; Picca, R. A.; Cioffi, N.

    2017-12-01

    Chemical, structural, morphological and micro-/macro-electrical properties of undoped and nitrogen-(N-)doped diamond films are determined by X-ray photoelectron spectroscopy, Raman and photoluminescence spectroscopies, field emission scanning electron microscopy, atomic force microscopy, scanning capacitance microscopy (SCM) and two points technique for I-V characteristics, respectively. The characterization results are very useful to examine and understand the relationship among these properties. The effect of the nitrogen incorporation in diamond films is investigated through the evolution of the chemical, structural, morphological and topographical features and of the electrical behavior. The distribution of the electrical current is first assessed at millimeter scale on the surface of diamond films and then at micrometer scale on small regions in order to establish the sites where the carriers preferentially move. Specifically, the SCM images indicate a non-uniform distribution of carriers on the morphological structures mainly located along the grain boundaries. A good agreement is found by comparing the electrical currents at the micro- and macro-scale. This work aims to highlight phenomena such as photo- and thermionic emission from N-doped diamond useful for microelectronic engineering.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-12-22

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Bogdanov, D.A.

    2006-08-01

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

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

    Science.gov (United States)

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

    2016-08-01

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

  6. The infrared optical properties of heavily B-doped nanocrystalline diamond films on low alkaline glass substrates

    Czech Academy of Sciences Publication Activity Database

    Remeš, Zdeněk; Nesladek, M.

    2006-01-01

    Roč. 203, č. 12 (2006), s. 3016-3020 ISSN 0031-8965 R&D Projects: GA AV ČR KJB100100623 Institutional research plan: CEZ:AV0Z10100521 Keywords : diamond * boron * dielectric function * glass Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.221, year: 2006

  7. 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.

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

    International Nuclear Information System (INIS)

    Jana, Sunirmal; Vuk, Angela Surca; Mallick, Aparajita; Orel, Boris; Biswas, Prasanta Kumar

    2011-01-01

    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.

  9. Chemical hole doping into large-area transition metal dichalcogenide monolayers using boron-based oxidant

    KAUST Repository

    Matsuoka, Hirofumi

    2018-01-18

    Hole carrier doping into single-crystalline transition metal dichalcogenide (TMDC) films can be achieved with various chemical reagents. However, large-area polycrystalline TMDC monolayers produced by a chemical vapor deposition (CVD) growth method have yet to be chemically doped. Here, we report that a salt of a two-coordinate boron cation, Mes2B+ (Mes: 2,4,6-trimethylphenyl group), with a chemically stable tetrakis(pentafluorophenyl)borate anion, [(C6F5)4B]−, can serve as an efficient hole-doping reagent for large-area CVD-grown tungsten diselenide (WSe2) films. Upon doping, the sheet resistance of large-area polycrystalline WSe2 monolayers decreased from 90 GΩ/sq to 3.2 kΩ/sq.

  10. Chemical hole doping into large-area transition metal dichalcogenide monolayers using boron-based oxidant

    Science.gov (United States)

    Matsuoka, Hirofumi; Kanahashi, Kaito; Tanaka, Naoki; Shoji, Yoshiaki; Li, Lain-Jong; Pu, Jiang; Ito, Hiroshi; Ohta, Hiromichi; Fukushima, Takanori; Takenobu, Taishi

    2018-02-01

    Hole carrier doping into single-crystalline transition metal dichalcogenide (TMDC) films can be achieved with various chemical reagents. However, large-area polycrystalline TMDC monolayers produced by a chemical vapor deposition (CVD) growth method have yet to be chemically doped. Here, we report that a salt of a two-coordinate boron cation, Mes2B+ (Mes: 2,4,6-trimethylphenyl group), with a chemically stable tetrakis(pentafluorophenyl)borate anion, [(C6F5)4B]‑, can serve as an efficient hole-doping reagent for large-area CVD-grown tungsten diselenide (WSe2) films. Upon doping, the sheet resistance of large-area polycrystalline WSe2 monolayers decreased from 90 GΩ/sq to 3.2 kΩ/sq.

  11. Polymeric Luminescent Compositions Doped with Beta-Diketonates Boron Difluoride as Material for Luminescent Solar Concentrator

    Science.gov (United States)

    Khrebtov, A. A.; Fedorenko, E. V.; Reutov, V. A.

    2017-11-01

    In this paper we investigated polymeric luminescent compositions based on polystyrene doped with beta diketonates boron difluoride. Transparent films with effective absorption in the ultraviolet and blue regions of the spectrum were obtained. Polymeric luminescent compositions based on the mixture of dyes allow expanding the absorption region and increase the radiation shift. A luminescent solar concentrator consisting of a glass plate coated with such film can be used for photovoltaic window application.

  12. Cu and Boron Doped Carbon Nitride for Highly Selective Oxidation of Toluene to Benzaldehyde

    Directory of Open Access Journals (Sweden)

    Hongling Han

    2015-07-01

    Full Text Available A novel Cu and boron doped graphitic carbon nitride catalyst (Cu-CNB was synthesized using cheap precursors and systematically characterized. The selective oxidation of toluene proceeded very smoothly over the catalyst at 70 °C using tert-butyl hydroperoxide (TBHP as the oxidant to exclusively afford benzaldehyde. The catalyst can be used for at least five cycles without decrease in activity and selectivity.

  13. Bare and boron-doped cubic silicon carbide nanowires for electrochemical detection of nitrite sensitively

    OpenAIRE

    Tao Yang; Liqin Zhang; Xinmei Hou; Junhong Chen; Kuo-Chih Chou

    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...

  14. Reduction in Recombination Current Density in Boron Doped Silicon Using Atomic Hydrogen

    Science.gov (United States)

    Young, Matthew Garett

    The solar industry has grown immensely in recent years and has reached a point where solar energy has now become inexpensive enough that it is starting to emerge as a mainstream electrical generation source. However, recent economic analysis has suggested that for solar to become a truly wide spread source of electricity, the costs still need to plummet by a factor of 8x. This demands new and innovative concepts to help lower such cost. In pursuit of this goal, this dissertation examines the use of atomic hydrogen to lessen the recombination current density in the boron doped region of n-type silicon solar cells. This required the development of a boron diffusion process that maintained the bulk lifetime of n-type silicon such that the recombination current density could be extracted by photoconductance spectroscopy. It is demonstrated that by hydrogenating boron diffusions, the majority carrier concentration can be controlled. By using symmetrically diffused test structures with quinhydrone-methanol surface passivation the recombination current density of a hydrogenated boron profile is shown to be less than that of a standard boron profile, by as much as 30%. This is then applied to a modified industrial silicon solar cell process to demonstrate an efficiency enhancement of 0.4%.

  15. Kinetics and thermodynamics of human serum albumin adsorption on silicon doped diamond like carbon

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Mukhtar H., E-mail: ahmed-m@email.ulster.ac.uk; Byrne, John A.; McLaughlin, James

    2015-03-15

    To gain a better understanding of protein adsorption onto biomaterial surfaces is required for the control of biocompatibility and bioactivity. Various samples of diamond like carbon (DLC) and silicon-doped DLC were synthesised using plasma enhanced chemical vapour deposition (PECVD). The effects of surface morphology on the interaction of human serum albumin (HSA) with doped and undoped DLC films was investigated using spectroscopic ellipsometry (SE) and other surface analysis techniques. The results highlighted an increase in both contact angle and hydrophobicity with increasing silicon dopant levels. A reduction on the contact angle values. After adsorption of HSA, the films showed a reduction in the contact angle with a significant change in the cosΔ and this gap increased with increasing surface coverage of HSA. The adsorption kinetics of HSA were also investigated and revealed that the maximum adsorption occurred at pH 5.0 and the process involved chemisorption. The experimental isotherm data were analysed using the Langmuir and Freundlich‎ models. The amount of HSA adsorbed increased with contact time and reached saturation ‎after 30 min. The adsorption ‎process was found to be pseudo first order with respect to the bulk concentration and was dependent on both the concentration of protein and surface characteristics of the samples. The amount of adsorbed HSA was higher with higher levels of silicon doping of the DLC. Therefore, doping DLC may provide an approach to controlling the protein adsorption. - Graphical abstract: The average thickness layer of HSA measurement onto surfaces of DLC and Si-DLC. - Highlights: • Diamond Like Carbon (DLC) and Silicon doped DLC were synthesised and characterised. • Si-DLC increases the hydrophobicity and decreases the surface free energy. • Adsorption study using human serum albumin (HSA). • The adsorbed amount of HSA increases with increasing of Silicon content DLC. • Adsorption process follow pseudo

  16. Doping chloro boron subnaphthalocyanines and chloro boron subphthalocyanine in simple OLED architectures yields warm white incandescent-like emissions

    Science.gov (United States)

    Plint, Trevor G.; Lessard, Benoît H.; Bender, Timothy P.

    2018-01-01

    We have incorporated chloro boron subphthalocyanine (Cl-BsubPc) and chloro boron subnapthalocyanines (Cl-ClnBsubNcs) into organic light emitting diodes (OLEDs) that enabled an overall warm white emission with CIE coordinates close to that of a 60 W incandescent lightbulb. More specifically, we have shown that Cl-BsubPc and Cl-ClnBsubNcs can be used as dopant emitters in a simple host-dopant architecture, and we have compared the use of NPB and Alq3 as potential hosts for these materials. When doped into Alq3, Cl-BsubPc shows a strong orange emission, and Cl-ClnBsubNcs shows a moderately strong red emission. We have further demonstrated that Cl-BsubPc and Cl-ClnBsubNcs can be co-doped into the same layer giving combined orange and red emission peaks. A "cascade" energy transfer mechanism of sequential absorption and re-emission is proposed. Device performance characteristics such as luminance, current efficiency, photoluminescence efficiency, and external quantum efficiency are tabulated. Additionally, in view of ongoing research into white emitting OLEDs for indoor lighting purposes, the Colour Rendering Index (CRI), R9 values, and CIE co-ordinates for these devices are also discussed. We conclude from this study that the BsubNc chromophore has potential application as a red dopant in OLEDs including for indoor lighting. Additionally, given the scope for axial and peripheral derivatization of the BsubNc motif, we believe that this chromophore has many unexplored molecular design handles that will affect its ultimate performance and application in OLEDs and other opto-electronic devices.

  17. Comparison between nano-diamond and carbon nanotube doping effects on critical current density and flux pinning in MgB2

    International Nuclear Information System (INIS)

    Cheng, C H; Yang, Y; Munroe, P; Zhao, Y

    2007-01-01

    Doping effects of nano-diamond and carbon nanotubes (CNTs) on critical current density of bulk MgB 2 have been studied. CNTs are found prone to be doped into the MgB 2 lattice whereas nano-diamond tends to form second-phase inclusions in the MgB 2 matrix, leading to a more significant improvement of J c (H) by doping by nano-diamond than by CNTs in MgB 2 . TEM reveals tightly packed MgB 2 nanograins (50-100 nm) with a dense distribution of diamond nanoparticles (10-20 nm) inside MgB 2 grains in nano-diamond-doped samples. Such a unique microstructure leads to a flux pinning behaviour different from that in CNTs-doped MgB 2

  18. Enhanced surface transfer doping of diamond by V{sub 2}O{sub 5} with improved thermal stability

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, Kevin G., E-mail: k.crawford.2@research.gla.ac.uk; Moran, David A. J. [School of Engineering, University of Glasgow, Glasgow G12 8LT (United Kingdom); Cao, Liang [High Magnetic Field Laboratory, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031, Anhui (China); Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, Singapore 117542 (Singapore); Qi, Dongchen, E-mail: d.qi@latrobe.edu.au [Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086 (Australia); Tallaire, Alexandre [LSPM-CNRS, Université Paris 13, Villetaneuse 93430 (France); Limiti, E.; Verona, C. [Department of Industrial Engineering, “Tor Vergata” University, Rome 00173 (Italy); Wee, Andrew T. S. [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, Singapore 117542 (Singapore)

    2016-01-25

    Surface transfer doping of hydrogen-terminated diamond has been achieved utilising V{sub 2}O{sub 5} as a surface electron accepting material. Contact between the oxide and diamond surface promotes the transfer of electrons from the diamond into the V{sub 2}O{sub 5} as revealed by the synchrotron-based high resolution photoemission spectroscopy. Electrical characterization by Hall measurement performed before and after V{sub 2}O{sub 5} deposition shows an increase in hole carrier concentration in the diamond from 3.0 × 10{sup 12} to 1.8 × 10{sup 13 }cm{sup −2} at room temperature. High temperature Hall measurements performed up to 300 °C in atmosphere reveal greatly enhanced thermal stability of the hole channel produced using V{sub 2}O{sub 5} in comparison with an air-induced surface conduction channel. Transfer doping of hydrogen-terminated diamond using high electron affinity oxides such as V{sub 2}O{sub 5} is a promising approach for achieving thermally stable, high performance diamond based devices in comparison with air-induced surface transfer doping.

  19. 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: 4.732, year: 2015

  20. Multi-phase structures of boron-doped copper tin sulfide nanoparticles synthesized by chemical bath deposition for optoelectronic devices

    Science.gov (United States)

    Rakspun, Jariya; Kantip, Nathakan; Vailikhit, Veeramol; Choopun, Supab; Tubtimtae, Auttasit

    2018-04-01

    We investigated the influence of boron doping on the structural, optical, and electrical properties of copper tin sulfide (CTS) nanoparticles coated on a WO3 surface and synthesized using chemical bath deposition. Boron doping at concentrations of 0.5, 1.0, 1.5, and 2.0 wt% was investigated. The X-ray diffraction pattern of CTS showed the presence of monoclinic Cu2Sn3S7, cubic Cu2SnS3, and orthorhombic Cu4SnS4. Boron doping influenced the preferred orientation of the nanoparticles for all phase structures and produced a lattice strain effect and changes in the dislocation density. Increasing the concentration of boron in CTS from 0.5 wt% to 2.0 wt% reduced the band gap for all phases of CTS from 1.46 to 1.29 eV and reduced the optical transmittance. Optical constants, such as the refractive index, extinction coefficient, and dissipation factor, were also obtained for B-doped CTS. The dispersion behavior of the refractive index was investigated in terms of a single oscillator model and the physical parameters were determined. Fourier transform infrared spectroscopy confirmed the successful synthesis of CTS nanoparticles. Cyclic voltammetry indicated that optimum boron doping (<1.5 wt% for all phases) resulted in desirable p-n junction behavior for optoelectronic applications.

  1. In-situ boron doping of chemical-bath deposited CdS thin films

    International Nuclear Information System (INIS)

    Khallaf, Hani; Park, S.; Schulte, Alfons; Chai, Guangyu; Lupan, Oleg; Chow, Lee; Heinrich, Helge

    2009-01-01

    In-situ boron doping of CdS using chemical-bath deposition (CBD) is reported. The effect of B doping on optical properties, as well as electrical properties, crystal structure, chemistry, and morphology of CdS films is studied. We present a successful approach towards B doping of CdS using CBD, where a resistivity as low as 1.7 x 10 -2 Ωcm and a carrier density as high as 1.91 x 10 19 cm -3 were achieved. The bandgap of B-doped films was found to slightly decrease as the[B]/[Cd] ratio in the solution increases. X-ray diffraction studies showed B 3+ ions likely enter the lattice substitutionally. A phase transition, due to annealing, as well as induced lattice defects, due to B doping, were detected by micro-Raman spectroscopy and transmission electron microscopy. The chemistry and morphology of films were unaffected by B doping. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Tuning dissociation using isoelectronically doped graphene and hexagonal boron nitride: Water and other small molecules

    Energy Technology Data Exchange (ETDEWEB)

    Al-Hamdani, Yasmine S. [Thomas Young Centre and London Centre for Nanotechnology, 17–19 Gordon Street, London WC1H 0AH (United Kingdom); Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ (United Kingdom); Alfè, Dario [Thomas Young Centre and London Centre for Nanotechnology, 17–19 Gordon Street, London WC1H 0AH (United Kingdom); Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT (United Kingdom); Lilienfeld, O. Anatole von [Institute of Physical Chemistry and National Center for Computational Design and Discovery of Novel Materials (MARVEL), Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel (Switzerland); Michaelides, Angelos, E-mail: angelos.michaelides@ucl.ac.uk [Thomas Young Centre and London Centre for Nanotechnology, 17–19 Gordon Street, London WC1H 0AH (United Kingdom); Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)

    2016-04-21

    Novel uses for 2-dimensional materials like graphene and hexagonal boron nitride (h-BN) are being frequently discovered especially for membrane and catalysis applications. Still however, a great deal remains to be understood about the interaction of environmentally and industrially relevant molecules such as water with these materials. Taking inspiration from advances in hybridising graphene and h-BN, we explore using density functional theory, the dissociation of water, hydrogen, methane, and methanol on graphene, h-BN, and their isoelectronic doped counterparts: BN doped graphene and C doped h-BN. We find that doped surfaces are considerably more reactive than their pristine counterparts and by comparing the reactivity of several small molecules, we develop a general framework for dissociative adsorption. From this a particularly attractive consequence of isoelectronic doping emerges: substrates can be doped to enhance their reactivity specifically towards either polar or non-polar adsorbates. As such, these substrates are potentially viable candidates for selective catalysts and membranes, with the implication that a range of tuneable materials can be designed.

  3. 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.

  4. Photodegradation of aniline by goethite doped with boron under ultraviolet and visible light irradiation

    International Nuclear Information System (INIS)

    Liu, Guanglong; Liao, Shuijiao; Zhu, Duanwei; Liu, Linghua; Cheng, Dongsheng; Zhou, Huaidong

    2011-01-01

    Highlights: → Goethite modified by boron was prepared by sol-gel method in presence of boron acid at the low temperature. → B-goethite has slight red shift in the band gap transition beside their stronger light absorption compared with pristine goethite. → The results showed that semiconductor photocatalytic reaction mechanism should exist in the process of aniline degradation with goethite and B-goethite as photocatalyst. -- Abstract: In the present study, goethite and goethite doped with boron (B-goethite) were employed to detect the presence or absence of semiconductor photocatalytic reaction mechanism in the reaction systems. B-goethite was prepared by sol-gel method in presence of boron acid in order to improve its photocatalystic efficiency under the ultraviolet and visible light irradiation. The optical properties of goethite and B-goethite were characterized by ultraviolet and visible absorption spectra and the result indicated that B-goethite has slight red shift in the band gap transition beside their stronger light absorption compared with pristine goethite. Degradation of aniline was investigated in presence of goethite and B-goethite in aqueous solution. It was found that the B-goethite photocatalyst exhibited enhanced ultraviolet and visible light photocatalytic activity in degradation of aniline compared with the pristine goethite. The photocatalytic degradation mechanism of B-goethite was discussed.

  5. Reduced-pressure chemical vapor deposition of boron-doped Si and Ge layers

    International Nuclear Information System (INIS)

    Bogumilowicz, Y.; Hartmann, J.M.

    2014-01-01

    We have studied the in-situ boron (B) doping of germanium (Ge) and silicon (Si) in Reduced Pressure-Chemical Vapor Deposition. Three growth temperatures have been investigated for the B-doping of Ge: 400, 600 and 750 °C at a constant growth pressure of 13300 Pa (i.e. 100 Torr). The B concentration in the Ge:B epilayer increases linearly with the diborane concentration in the gaseous phase. Single-crystalline Ge:B layers with B concentrations in-between 9 ∙ 10 17 and 1 ∙ 10 20 cm −3 were achieved. For the in-situ B doping of Si at 850 °C, two dichlorosilane mass flow ratios (MFR) have been assessed: F[SiH 2 Cl 2 ]/F[H 2 ] = 0.0025 and F[SiH 2 Cl 2 ]/F[H 2 ] = 0.0113 at a growth pressure of 2660 Pa (i.e. 20 Torr). Linear boron incorporation with the diborane concentration in the gas phase has been observed and doping levels in-between 3.5 ∙ 10 17 and 1 ∙ 10 20 cm −3 were achieved. We almost kept the same ratio of B versus Si atoms in the gas phase and in the Si epilayer. By contrast, roughly half of the B atoms present in the gas phase were incorporated in the Ge:B layers irrespective of the growth temperature. X-Ray Diffraction (XRD) allowed us to extract from the angular position of the Ge:B layer diffraction peak the substitutional B concentration. Values close to the B concentrations obtained by 4-probe resistivity measurements were obtained. Ge:B layers were smooth (< 1 m root mean square roughness associated with 20 × 20 μm 2 Atomic Force Microscopy images). Only for high F[B 2 H 6 ]/F[GeH 4 ] MFR (3.2 10 −3 ) did the Ge:B layers became rough; they were however still mono-crystalline (XRD). Above this MFR value, Ge:B layers became polycrystalline. - Highlights: • Boron doping of germanium and silicon in Reduced Pressure-Chemical Vapor Deposition • Linear boron incorporation in Ge:B and Si:B with the diborane flow • Single-crystal Ge:B layers with B concentrations in-between 9 ∙ 10 17 and 1 ∙ 10 20 cm −3 • Single-crystal Si

  6. N-Doped Hybrid Graphene and Boron Nitride Armchair Nanoribbons As Nonmagnetic Semiconductors with Widely Tunable Electronic Properties

    Science.gov (United States)

    Habibpour, Razieh; Kashi, Eslam; Vazirib, Raheleh

    2018-03-01

    The electronic and chemical properties of N-doped hybrid graphene and boron nitride armchair nanoribbons (N-doped a-GBNNRs) in comparison with graphene armchair nanoribbon (pristine a-GNR) and hybrid graphene and boron nitride armchair nanoribbon (C-3BN) are investigated using the density functional theory method. The results show that all the mentioned nanoribbons are nonmagnetic direct semiconductors and all the graphitic N-doped a-GBNNRs are n-type semiconductors while the rest are p-type semiconductors. The N-doped graphitic 2 and N-doped graphitic 3 structures have the lowest work function and the highest number of valence electrons (Lowdin charges) which confirms that they are effective for use in electronic device applications.

  7. Effect of sintering temperature and boron carbide content on the wear behavior of hot pressed diamond cutting segments

    Directory of Open Access Journals (Sweden)

    Islak S.

    2015-01-01

    Full Text Available The aim of this study was to investigate the effect of sintering temperature and boron carbide content on wear behavior of diamond cutting segments. For this purpose, the segments contained 2, 5 and 10 wt.% B4C were prepared by hot pressing process carried out under a pressure of 35 MPa, at 600, 650 and 700 °C for 3 minutes. The transverse rupture strength (TRS of the segments was assessed using a three-point bending test. Ankara andesite stone was cut to examine the wear behavior of segments with boron carbide. Microstructure, surfaces of wear and fracture of segments were determined by scanning electron microscopy (SEM-EDS, and X-ray diffraction (XRD analysis. As a result, the wear rate decreased significantly in the 0-5 wt.% B4C contents, while it increased in the 5-10 wt.% B4C contents. With increase in sintering temperature, the wear rate decreased due to the hard matrix.

  8. Friction and wear performance of diamond-like carbon, boron carbide, and titanium carbide coatings against glass

    International Nuclear Information System (INIS)

    Daniels, B.K.; Brown, D.W.; Kimock, F.M.

    1997-01-01

    Protection of glass substrates by direct ion beam deposited diamond-like carbon (DLC) coatings was observed using a commercial pin-on-disk instrument at ambient conditions without lubrication. Ion beam sputter-deposited titanium carbide and boron carbide coatings reduced sliding friction, and provided tribological protection of silicon substrates, but the improvement factor was less than that found for DLC. Observations of unlubricated sliding of hemispherical glass pins at ambient conditions on uncoated glass and silicon substrates, and ion beam deposited coatings showed decreased wear in the order: uncoated glass>uncoated silicon>boron carbide>titanium carbide>DLC>uncoated sapphire. Failure mechanisms varied widely and are discussed. Generally, the amount of wear decreased as the sliding friction decreased, with the exception of uncoated sapphire substrates, for which the wear was low despite very high friction. There is clear evidence that DLC coatings continue to protect the underlying substrate long after the damage first penetrates through the coating. The test results correlate with field use data on commercial products which have shown that the DLC coatings provide substantial extension of the useful lifetime of glass and other substrates. copyright 1997 Materials Research Society

  9. 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.

  10. Bare and boron-doped cubic silicon carbide nanowires for electrochemical detection of nitrite sensitively.

    Science.gov (United States)

    Yang, Tao; Zhang, Liqin; Hou, Xinmei; Chen, Junhong; Chou, Kuo-Chih

    2016-04-25

    Fabrication of eletrochemical sensors based on wide bandgap compound semiconductors has attracted increasing interest in recent years. Here we report for the first time electrochemical nitrite sensors based on cubic silicon carbide (SiC) nanowires (NWs) with smooth surface and boron-doped cubic SiC NWs with fin-like structure. Multiple techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electron energy loss spectroscopy (EELS) were used to characterize SiC and boron-doped SiC NWs. As for the electrochemical behavior of both SiC NWs electrode, the cyclic voltammetric results show that both SiC electrodes exhibit wide potential window and excellent electrocatalytic activity toward nitrite oxidation. Differential pulse voltammetry (DPV) determination reveals that there exists a good linear relationship between the oxidation peak current and the concentration in the range of 50-15000 μmoL L(-1) (cubic SiC NWs) and 5-8000 μmoL L(-1) (B-doped cubic SiC NWs) with the detection limitation of 5 and 0.5 μmoL L(-1) respectively. Compared with previously reported results, both as-prepared nitrite sensors exhibit wider linear response range with comparable high sensitivity, high stability and reproducibility.

  11. Effect of Boron Doping on Cellular Discontinuous Precipitation for Age-Hardenable Cu–Ti Alloys

    Directory of Open Access Journals (Sweden)

    Satoshi Semboshi

    2015-06-01

    Full Text Available The effects of boron doping on the microstructural evolution and mechanical and electrical properties of age-hardenable Cu–4Ti (at.% alloys are investigated. In the quenched Cu–4Ti–0.03B (at.% alloy, elemental B (boron is preferentially segregated at the grain boundaries of the supersaturated solid-solution phase. The aging behavior of the B-doped alloy is mostly similar to that of conventional age-hardenable Cu–Ti alloys. In the early stage of aging at 450 °C, metastable β′-Cu4Ti with fine needle-shaped precipitates continuously form in the matrix phase. Cellular discontinuous precipitates composed of the stable β-Cu4Ti and solid-solution laminates are then formed and grown at the grain boundaries. However, the volume fraction of the discontinuous precipitates is lower in the Cu–4Ti–0.03B alloy than the Cu–4Ti alloy, particularly in the over-aging period of 72–120 h. The suppression of the formation of discontinuous precipitates eventually results in improvement of the hardness and tensile strength. It should be noted that minor B doping of Cu–Ti alloys also effectively enhances the elongation to fracture, which should be attributed to segregation of B at the grain boundaries.

  12. Electrochemical Properties of Boron-Doped Fullerene Derivatives for Lithium-Ion Battery Applications.

    Science.gov (United States)

    Sood, Parveen; Kim, Ki Chul; Jang, Seung Soon

    2017-12-07

    The high electron affinity of fullerene C 60 coupled with the rich chemistry of carbon makes it a promising material for cathode applications in lithium-ion batteries. Since boron has one electron less than carbon, the presence of boron on C 60 cages is expected to generate electron deficiency in C 60 , and thereby to enhance its electron affinity. By using density functional theory (DFT), we studied the redox potentials and electronic properties of C 60 and C 59 B. We have found that doping C 60 with one boron atom results in a substantial increase in redox potential from 2.462 V to 3.709 V, which was attributed to the formation of an open shell system. We also investigated the redox and electronic properties of C 59 B functionalized with various redox-active oxygen containing functional groups (OCFGs). For the combination of functionalization with OCFGs and boron doping, it is found that the enhancement of redox potential is reduced, which is mainly attributed to the open shell structure being changed to a closed-shell one. Nevertheless, the redox potentials are still higher than that of pristine C 60 . From the observation that the lowest unoccupied molecular orbital of closed-shell OCFG- functionalized C 59 B is correlated well with the redox potential, it was confirmed that the spin state is crucial to be considered to understand the relationship between electronic structure and redox properties. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Boron-doped carbon nanotubes as metal-free electrocatalyst for dye-sensitized solar cells: Heteroatom doping level effect on tri-iodide reduction reaction

    Science.gov (United States)

    Yeh, Min-Hsin; Leu, Yow-An; Chiang, Wei-Hung; Li, Yan-Sheng; Chen, Guan-Lin; Li, Ta-Jen; Chang, Ling-Yu; Lin, Lu-Yin; Lin, Jiang-Jen; Ho, Kuo-Chuan

    2018-01-01

    Heteroatom-doped carbons have been substantially applied on electrochemical applications for their exceptional electrocatalytic ability and electric conductivity. Among the doping elements, electron-deficient boron (B) is considered to be a promising heteroatom for the chemical doping of carbon materials to modify the chemically inert sp2 carbon structure and thus activate the abundant free-flowing π electrons. In this study, B-doped carbon nanotubes (BCNTs) with various boron doping atomic percentages (0.40-3.92 at%) are synthesized and used as a electrocatalyst on the counter electrode (CE) of dye-sensitized solar cells (DSSCs) for investigating the effect of boron doping on carbon materials. A solar-to-electricity conversion efficiency (η) of 7.17 ± 0.11% is achieved for a DSSC with a CE containing BCNTs with optimized B doping concentration (BCNT-0.40 at%), which is higher than that of the cells with CEs consisting of pristine carbon nanotubes (CNT, η = 5.98 ± 0.20%) and is comparable to that of the cell with a Pt CE (η = 7.98 ± 0.05%). It is also noteworthy from a practical viewpoint that the developed atmospheric-pressure synthesis method for synthesizing BCNT is amenable to industrial-scale production since a requirement for vacuum system can be avoided.

  14. Transient photoresponse of nitrogen-doped ultrananocrystalline diamond electrodes in saline solution

    Energy Technology Data Exchange (ETDEWEB)

    Ahnood, Arman, E-mail: arman.ahnood@unimelb.edu.au; Ganesan, Kumaravelu; Stacey, Alastair; Prawer, Steven [School of Physics, University of Melbourne, Melbourne, Victoria 3010 (Australia); Simonov, Alexandr N.; Spiccia, Leone [School of Chemistry and the ARC Centre of Excellence for Electromaterials Science, Monash University, Melbourne, Victoria 3800 (Australia); Laird, Jamie S. [CSIRO, Minerals Resources Flagship, School of Physics, University of Melbourne, Melbourne, Victoria 3010 (Australia); Maturana, Matias I. [National Vision Research Institute, Australian College of Optometry, Carlton, Victoria 3053 (Australia); NeuroEngineering Laboratory, Department of Electrical and Electronic Engineering, University of Melbourne, Parkville, Victoria 3010 (Australia); Ibbotson, Michael R. [National Vision Research Institute, Australian College of Optometry, Carlton, Victoria 3053 (Australia); ARC Centre of Excellence for Integrative Brain Function, Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria 3010 (Australia)

    2016-03-07

    Beyond conventional electrically-driven neuronal stimulation methods, there is a growing interest in optically-driven approaches. In recent years, nitrogen-doped ultrananocrystalline diamond (N-UNCD) has emerged as a strong material candidate for use in electrically-driven stimulation electrodes. This work investigates the electrochemical activity of N-UNCD in response to pulsed illumination, to assess its potential for use as an optically-driven stimulation electrode. Whilst N-UNCD in the as-grown state exhibits a weak photoresponse, the oxygen plasma treated film exhibits two orders of magnitude enhancement in its sub-bandgap open circuit photovoltage response. The enhancement is attributed to the formation of a dense network of oxygen-terminated diamond nanocrystals at the N-UNCD surface. Electrically connected to the N-UNCD bulk via sub-surface graphitic grain boundaries, these diamond nanocrystals introduce a semiconducting barrier between the sub-surface graphitic semimetal and the electrolyte solution, leading to a photovoltage under irradiation with wavelengths of λ = 450 nm and shorter. Within the safe optical exposure limit of 2 mW mm{sup −2}, charge injection capacity of 0.01 mC cm{sup −2} is achieved using a 15 × 15 μm electrode, meeting the requirements for extracellular and intercellular stimulation. The nanoscale nature of processes presented here along with the diamond's biocompatibility and biostability open an avenue for the use of oxygen treated N-UNCD as optically driven stimulating electrodes.

  15. Plasma Synthesized Doped Boron Nanopowder for MgB2 Superconductors

    Energy Technology Data Exchange (ETDEWEB)

    James V. Marzik

    2012-03-26

    Under this program, a process to synthesize nano-sized doped boron powder by a plasma synthesis process was developed and scaled up from 20 gram batches at program start to over 200 grams by program end. Over 75 batches of boron nanopowder were made by RF plasma synthesis. Particle sizes were typically in the 20-200 nm range. The powder was synthesized by the reductive pyrolysis of BCl{sub 3} in hydrogen in an RF plasma. A wide range of process parameters were investigated including plasma power, torch geometry, gas flow rates, and process pressure. The powder-in-tube technique was used to make monofilament and multifilament superconducting wires. MgB{sub 2} wire made with Specialty Materials plasma synthesized boron nanopowder exhibited superconducting properties that significantly exceeded the program goals. Superconducting critical currents, J{sub c}, in excess of 10{sup 5} A cm{sup -2} at magnetic fields of 8 tesla were reproducibly achieved. The upper critical magnetic field in wires fabricated with program boron powder were H{sub c2}(0) = 37 tesla, demonstrating the potential of these materials for high field magnet applications. T{sub c} in carbon-doped MgB{sub 2} powder showed a systematic decrease with increasing carbon precursor gas flows, indicating the plasma synthesis process can give precise control over dopant concentrations. Synthesis rates increased by a factor of 400% over the course of the program, demonstrating the scalability of the powder synthesis process. The plasma synthesis equipment at Specialty Materials has successfully and reproducibly made high quality boron nanopowder for MgB{sub 2} superconductors. Research and development from this program enabled Specialty Materials to successfully scale up the powder synthesis process by a factor of ten and to double the size of its powder pilot plant. Thus far the program has been a technical success. It is anticipated that continued systematic development of plasma processing parameters, dopant

  16. Plasma Synthesized Doped Boron Nanopowder for MgB2 Superconductors

    International Nuclear Information System (INIS)

    Marzik, James V.

    2012-01-01

    Under this program, a process to synthesize nano-sized doped boron powder by a plasma synthesis process was developed and scaled up from 20 gram batches at program start to over 200 grams by program end. Over 75 batches of boron nanopowder were made by RF plasma synthesis. Particle sizes were typically in the 20-200 nm range. The powder was synthesized by the reductive pyrolysis of BCl 3 in hydrogen in an RF plasma. A wide range of process parameters were investigated including plasma power, torch geometry, gas flow rates, and process pressure. The powder-in-tube technique was used to make monofilament and multifilament superconducting wires. MgB 2 wire made with Specialty Materials plasma synthesized boron nanopowder exhibited superconducting properties that significantly exceeded the program goals. Superconducting critical currents, J c , in excess of 10 5 A cm -2 at magnetic fields of 8 tesla were reproducibly achieved. The upper critical magnetic field in wires fabricated with program boron powder were H c2 (0) = 37 tesla, demonstrating the potential of these materials for high field magnet applications. T c in carbon-doped MgB 2 powder showed a systematic decrease with increasing carbon precursor gas flows, indicating the plasma synthesis process can give precise control over dopant concentrations. Synthesis rates increased by a factor of 400% over the course of the program, demonstrating the scalability of the powder synthesis process. The plasma synthesis equipment at Specialty Materials has successfully and reproducibly made high quality boron nanopowder for MgB 2 superconductors. Research and development from this program enabled Specialty Materials to successfully scale up the powder synthesis process by a factor of ten and to double the size of its powder pilot plant. Thus far the program has been a technical success. It is anticipated that continued systematic development of plasma processing parameters, dopant chemistry and concentration, wire

  17. Boron-Doped Graphite for High Work Function Carbon Electrode in Printable Hole-Conductor-Free Mesoscopic Perovskite Solar Cells.

    Science.gov (United States)

    Duan, Miao; Tian, Chengbo; Hu, Yue; Mei, Anyi; Rong, Yaoguang; Xiong, Yuli; Xu, Mi; Sheng, Yusong; Jiang, Pei; Hou, Xiaomeng; Zhu, Xiaotong; Qin, Fei; Han, Hongwei

    2017-09-20

    Work function of carbon electrodes is critical in obtaining high open-circuit voltage as well as high device performance for carbon-based perovskite solar cells. Herein, we propose a novel strategy to upshift work function of carbon electrode by incorporating boron atom into graphite lattice and employ it in printable hole-conductor-free mesoscopic perovskite solar cells. The high-work-function boron-doped carbon electrode facilitates hole extraction from perovskite as verified by photoluminescence. Meanwhile, the carbon electrode is endowed with an improved conductivity because of a higher graphitization carbon of boron-doped graphite. These advantages of the boron-doped carbon electrode result in a low charge transfer resistance at carbon/perovskite interface and an extended carrier recombination lifetime. Together with the merit of both high work function and conductivity, the power conversion efficiency of hole-conductor-free mesoscopic perovskite solar cells is increased from 12.4% for the pristine graphite electrode-based cells to 13.6% for the boron-doped graphite electrode-based cells with an enhanced open-circuit voltage and fill factor.

  18. Highly conductive boron-doped hydrogenated microcrystalline silicon films obtained by hot wire deposition

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, W. [IEF5-Photovoltaik, Forschungszentrum Juelich (Germany); Malibu GmbH and Co. KG, Bielefeld (Germany); Carius, R.; Einsele, F.; Lennartz, D.; Niessen, L.; Pennartz, F. [IEF5-Photovoltaik, Forschungszentrum Juelich (Germany)

    2010-04-15

    The growth of highly conductive boron doped microcrystalline silicon by the hot wire method was studied. Various series of films were deposited to investigate the influence of the deposition parameters on conductivity, crystallinity and (void-related) microstructure. Maximum (room temperature) conductivities > 200 S/cm with carrier mobilities > 2.5 cm{sup 2}/Vs were achieved. While a high crystallinity is the major requirement for achieving high conductivities, the microstructure is also of influence. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. First principles Raman study of boron and nitrogen doped planar T-graphene clusters

    International Nuclear Information System (INIS)

    Bandyopadhyay, Arka; Pal, Parthasarathi; Chowdhury, Suman; Jana, Debnarayan

    2015-01-01

    Tetragonal graphene (TG) is one of the theoretically proposed dynamically stable graphene allotropes. In this study, the Raman spectra, IR spectra and some electronic properties of pristine and doped (single boron (B) and nitrogen (N)) TG have been investigated by first-principles based density functional theory (DFT) at the B3LYP/6-31G(d) level. Formation energy computation indicates that for the pristine structures, stability increases with increasing cluster size. In addition, for a particular cluster size, single B doping introduces some distortion in the system while single N doping increases the stability of it. The Raman spectrum of the N doped system is dominated by a single peak but for the B doped system several intense lines are found. For all the structures low intensity similar breathing-like modes have been observed. Besides, relatively low (high) intensity Raman lines are found for single B (N) doping compared to those of the pristine one. The vibrational study also reveals the existence of a prominent phonon Raman line for pristine clusters which hardly changes its position and nature of vibration with varying cluster size. So this mode can be used for identification of pristine TG structures. Unlike pristine TG, the doped structures possess non-zero finite dipole moments due to asymmetry in charge distribution. Large values of the HOMO–LUMO gap as well as the absence of DOS at the Fermi level lead to the semiconducting nature of all the structures. All these theoretical predictions from DFT calculations may shed light on experimental observations involving TG systems. (paper)

  20. Active brazed diamond and cubic boron nitride interfacial nanostructure and application

    International Nuclear Information System (INIS)

    Klotz, U.E.; Elsener, H.R.; Elsener, H.R.

    2005-01-01

    Active brazing is an effective technique for joining diamond or cBN grit onto metallic substrates. Current use of this technique is being made for super abrasive, high performance tools. The lecture will give an overview over different aspects such as (i) tool performance in selected applications, (ii) interfacial nanostructure between super abrasive grit and brazing alloys matrix, (iii) attempts to computer model such interface reactions and (iv) recent improvements of the abrasion resistance of the brazing alloy itself. Super abrasive tools with outstanding performance in applications such as grinding, honing or stone cutting can be manufactured by a single-layer of brazed diamond or cBN grit. A method to obtain regular grit patterns will be presented. Examples of prototype tools and their performance in different applications will be shown. The investigation of interface reactions between diamond and active brazing alloys plays an important role to further improve the brazing process and resulting tool performance. The interfacial nanostructure is characterised by a thin reaction layer of Ti with diamond and cBN, respectively. Results for Ag- and Cu-based brazing alloys will be presented and discussed in view of the influence of brazing process parameters and brazing alloy matrix. Computer modelling of the thermodynamics and kinetics of the interface reactions may allow optimising the process parameters. This requires reliable databases currently being built up. The potential of such methods in ceramic to metal joining will be described. The abrasion resistance of brazing alloys itself plays an important role for tool performance. A new method to achieve a dispersion of nano sized TiC precipitates in the alloy matrix by addition of an organic binder, decomposing during brazing will be presented. In an outlook further applications of brazed diamond grit, such as thermal management materials will be discussed. (author)

  1. Effects of domain shape and size in the electronic and optical properties of boron nitride doped graphenes

    Science.gov (United States)

    Leite, L.; Azevedo, S.; de Lima Bernardo, Bertúlio

    2017-11-01

    The co-dopant, boron nitride (BN) doped graphene (BNG), has been synthesized recently and has been shown to be an efficient method to engineer band gaps in graphene. The control of the dopant domain size allows us to tailor the electronic structure and properties of graphene. We have studied the electronic and optical properties of boron nitride doped graphene with different domain shapes and sizes. Seven different doping configurations (three quantum dot types and four triangular-shaped types, being two with nitrogen and two with boron at the edges, respectively) were chosen and calculated making use of first-principles calculations based on the density functional theory (DFT). Band gap opening has been observed for such structures whose magnitude increases with the doping concentration. We found that only atoms near the dopant boundary make significant contributions to the near Fermi energy. The configurations with triangular-shaped nanodomains with nitrogen and boron at the edge show a different structure of absorption and conductivity peaks when compared with the quantum dot type structures and graphene. Such findings suggest a controllable way of manipulating the optical properties of doped graphene materials.

  2. Multi-functional spintronic devices based on boron- or aluminum-doped silicene nanoribbons

    Science.gov (United States)

    Liu, Y. S.; Dong, Y. J.; Zhang, J.; Yu, H. L.; Feng, J. F.; Yang, X. F.

    2018-03-01

    Zigzag silicene nanoribbons (ZSiNRs) in the ferromagnetic edge ordering have a metallic behavior, which limits their applications in spintronics. Here a robustly half-metallic property is achieved by the boron substitution doping at the edge of ZSiNRs. When the impurity atom is replaced by the aluminum atom, the doped ZSiNRs possess a spin semiconducting property. Its band gap is suppressed with the increase of ribbon’s width, and a pure thermal spin current is achieved by modulating ribbon’s width. Moreover, a negative differential thermoelectric resistance in the thermal charge current appears as the temperature gradient increases, which originates from the fact that the spin-up and spin-down thermal charge currents have diverse increasing rates at different temperature gradient regions. Our results put forward a promising route to design multi-functional spintronic devices which may be applied in future low-power-consumption technologies.

  3. 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.

  4. Complex Boron Redistribution in P+ Doped-polysilicon / Nitrogen Doped Silicon Bi-layers during Activation Annealing

    Science.gov (United States)

    Abadli, S.; Mansour, F.; Perrera, E. Bedel

    We have investigated and modeled the complex phenomenon of boron (B) redistribution process in strongly doped silicon bilayers structure. A one-dimensional two stream transfer model well adapted to the particular structure of bi- layers and to the effects of strong-concentrations has been developed. This model takes into account the instantaneous kinetics of B transfer, trapping, clustering and segregation during the thermal B activation annealing. The used silicon bi-layers have been obtained by low pressure chemical vapor deposition (LPCVD) method, using in-situ nitrogen- doped-silicon (NiDoS) layer and strongly B doped polycrystalline-silicon (P+) layer. To avoid long redistributions, thermal annealing was carried out at relatively lowtemperatures (600 °C and 700 °C) for various times ranging between 30 minutes and 2 hours. The good adjustment of the simulated profiles with the experimental secondary ion mass spectroscopy (SIMS) profiles allowed a fundamental understanding about the instantaneous physical phenomena giving and disturbing the complex B redistribution profiles-shoulders kinetics.

  5. Complex boron redistribution kinetics in strongly doped polycrystalline-silicon/nitrogen-doped-silicon thin bi-layers

    Energy Technology Data Exchange (ETDEWEB)

    Abadli, S. [Department of Electrical Engineering, University Aout 1955, Skikda, 21000 (Algeria); LEMEAMED, Department of Electronics, University Mentouri, Constantine, 25000 (Algeria); Mansour, F. [LEMEAMED, Department of Electronics, University Mentouri, Constantine, 25000 (Algeria); Pereira, E. Bedel [CNRS-LAAS, 7 avenue du colonel Roche, 31077 Toulouse (France)

    2012-10-15

    We have investigated the complex behaviour of boron (B) redistribution process via silicon thin bi-layers interface. It concerns the instantaneous kinetics of B transfer, trapping, clustering and segregation during the thermal B activation annealing. The used silicon bi-layers have been obtained by low pressure chemical vapor deposition (LPCVD) method at 480 C, by using in-situ nitrogen-doped-silicon (NiDoS) layer and strongly B doped polycrystalline-silicon (P{sup +}) layer. To avoid long-range B redistributions, thermal annealing was carried out at relatively low-temperatures (600 C and 700 C) for various times ranging between 30 min and 2 h. To investigate the experimental secondary ion mass spectroscopy (SIMS) doping profiles, a redistribution model well adapted to the particular structure of two thin layers and to the effects of strong-concentrations has been established. The good adjustment of the simulated profiles with the experimental SIMS profiles allowed a fundamental understanding about the instantaneous physical phenomena giving and disturbing the complex B redistribution profiles-shoulders. The increasing kinetics of the B peak concentration near the bi-layers interface is well reproduced by the established model. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Corrosion and Wear Behaviors of Cr-Doped Diamond-Like Carbon Coatings

    Science.gov (United States)

    Viswanathan, S.; Mohan, L.; Bera, Parthasarathi; Kumar, V. Praveen; Barshilia, Harish C.; Anandan, C.

    2017-08-01

    A combination of plasma-enhanced chemical vapor deposition and magnetron sputtering techniques has been employed to deposit chromium-doped diamond-like carbon (DLC) coatings on stainless steel, silicon and glass substrates. The concentrations of Cr in the coatings are varied by changing the parameters of the bipolar pulsed power supply and the argon/acetylene gas composition. The coatings have been studied for composition, morphology, surface nature, nanohardness, corrosion resistance and wear resistance properties. The changes in I D / I G ratio with Cr concentrations have been obtained from Raman spectroscopy studies. Ratio decreases with an increase in Cr concentration, and it has been found to increase at higher Cr concentration, indicating the disorder in the coating. Carbide is formed in Cr-doped DLC coatings as observed from XPS studies. There is a decrease in sp 3/ sp 2 ratios with an increase in Cr concentration, and it increases again at higher Cr concentration. Nanohardness studies show no clear dependence of hardness on Cr concentration. DLC coatings with lower Cr contents have demonstrated better corrosion resistance with better passive behavior in 3.5% NaCl solution, and corrosion potential is observed to move toward nobler (more positive) values. A low coefficient of friction (0.15) at different loads is observed from reciprocating wear studies. Lower wear volume is found at all loads on the Cr-doped DLC coatings. Wear mechanism changes from abrasive wear on the substrate to adhesive wear on the coating.

  7. Iron, nitrogen and silicon doped diamond like carbon (DLC) thin films: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Sekhar C., E-mail: Raysc@unisa.ac.za [Department of Physics, College of Science, Engineering and Technology, University of South Africa, Private Bag X6, Florida, 1710, Science Campus, Christiaan de Wet and Pioneer Avenue, Florida Park, Johannesburg (South Africa); Pong, W.F. [Department of Physics, Tamkang University, Tamsui 251, New Taipei City, Taiwan (China); Papakonstantinou, P. [Nanotechnology and Integrated Bio-Engineering Centre, University of Ulster, Shore Road, Newtownabbey BT37 0QB (United Kingdom)

    2016-07-01

    The X-ray absorption near edge structure (XANES), X-ray photoelectron spectroscopy (XPS), valence band photoemission (VB-PES) and Raman spectroscopy results show that the incorporation of nitrogen in pulsed laser deposited diamond like carbon (DLC) thin films, reverts the sp{sup 3} network to sp{sup 2} as evidenced by an increase of the sp{sup 2} cluster and I{sub D}/I{sub G} ratio in C K-edge XANES and Raman spectra respectively which reduces the hardness/Young's modulus into the film network. Si-doped DLC film deposited in a plasma enhanced chemical vapour deposition process reduces the sp{sup 2} cluster and I{sub D}/I{sub G} ratio that causes the decrease of hardness/Young's modulus of the film structure. The Fe-doped DLC films deposited by dip coating technique increase the hardness/Young's modulus with an increase of sp{sup 3}-content in DLC film structure. - Highlights: • Fe, N and Si doped DLC films deposited by dip, PLD and PECVD methods respectively • DLC:Fe thin films have higher hardness/Young's modulus than DLC:N(:Si) thin films. • sp{sup 3} and sp{sup 2} contents are estimated from C K-edge XANES and VB-PES measurements.

  8. Effect of Si/Fe ratio on the boron and phosphorus doping efficiency of β-FeSi2 by magnetron sputtering

    International Nuclear Information System (INIS)

    Xu Jiaxiong; Yao Ruohe

    2011-01-01

    Boron-doped or phosphorus-doped β-FeSi 2 thin films have been prepared on silicon substrate by magnetron sputtering. Effects of Si/Fe ratio on the boron and phosphorus doping efficiencies have been studied from the resistivities of doped β-FeSi 2 thin films and current-voltage characteristics of doped β-FeSi 2 /Si heterojunctions. The experimental results reveal that the carrier concentration and doping efficiency of boron or phosphorus dopants at the Fe-rich side are higher than that at the Si-rich side. The effect of Si/Fe ratio can be deduced from the comparison of the formation energies under two extreme conditions. At the Fe-rich limit condition, the formation energy of boron or phosphorous doping is lower than that at the Si-rich condition. Therefore, the activation of impurities is more effective at the Fe-rich side. These results demonstrate that the boron-doped and phosphorous-doped β-FeSi 2 thin films should be kept at the Fe-rich side to avoid the unexpected doping sites and low doping efficiency.

  9. Role of aluminum in silver paste contact to boron-doped silicon emitters

    Directory of Open Access Journals (Sweden)

    Wei Wu

    2017-01-01

    Full Text Available The addition of aluminum to silver metallization pastes has been found to lower the contact resistivity of a silver metallization on boron-doped silicon emitters for n-type Si solar cells. However, the addition of Al also induces more surface recombination and increases the Ag pattern′s line resistivity, both of which ultimately limit the cell efficiency. There is a need to develop a fundamental understanding of the role that Al plays in reducing the contact resistivity and to explore alternative additives. A fritless silver paste is used to allow direct analysis of the impact of Al on the Ag-Si interfacial microstructure and isolate the influence of Al on the electrical contact from the complicated Ag-Si interfacial glass layer. Electrical analysis shows that in a simplified system, Al decreases the contact resistivity by about three orders of magnitude. Detailed microstructural studies show that in the presence of Al, microscale metallic spikes of Al-Ag alloy and nanoscale metallic spikes of Ag-Si alloy penetrate the surface of the boron-doped Si emitters. These results demonstrate the role of Al in reducing the contact resistivity through the formation of micro- and nano-scale metallic spikes, allowing the direct contact to the emitters.

  10. Effects of manganese doping on the structure evolution of small-sized boron clusters

    Science.gov (United States)

    Zhao, Lingquan; Qu, Xin; Wang, Yanchao; Lv, Jian; Zhang, Lijun; Hu, Ziyu; Gu, Guangrui; Ma, Yanming

    2017-07-01

    Atomic doping of clusters is known as an effective approach to stabilize or modify the structures and properties of resulting doped clusters. We herein report the effect of manganese (Mn) doping on the structure evolution of small-sized boron (B) clusters. The global minimum structures of both neutral and charged Mn doped B cluster \\text{MnB}nQ (n  =  10-20 and Q  =  0, ±1) have been proposed through extensive first-principles swarm-intelligence based structure searches. It is found that Mn doping has significantly modified the grow behaviors of B clusters, leading to two novel structural transitions from planar to tubular and then to cage-like B structures in both neutral and charged species. Half-sandwich-type structures are most favorable for small \\text{MnB}n-/0/+ (n  ⩽  13) clusters and gradually transform to Mn-centered double-ring tubular structures at \\text{MnB}16-/0/+ clusters with superior thermodynamic stabilities compared with their neighbors. Most strikingly, endohedral cages become the ground-state structures for larger \\text{MnB}n-/0/+ (n  ⩾  19) clusters, among which \\text{MnB}20+ adopts a highly symmetric structure with superior thermodynamic stability and a large HOMO-LUMO gap of 4.53 eV. The unique stability of the endohedral \\text{MnB}\\text{20}+ cage is attributed to the geometric fit and formation of 18-electron closed-shell configuration. The results significantly advance our understanding about the structure and bonding of B-based clusters and strongly suggest transition-metal doping as a viable route to synthesize intriguing B-based nanomaterials.

  11. Investigation of Physical Properties and Electrochemical Behavior of Nitrogen-Doped Diamond-Like Carbon Thin Films

    Directory of Open Access Journals (Sweden)

    Rattanakorn Saensak

    2014-03-01

    Full Text Available This work reports characterizations of diamond-like carbon (DLC films used as electrodes for electrochemical applications. DLC thin films are prepared on glass slides and silicon substrates by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD using a gas mixture of methane and hydrogen. In addition, the DLC films are doped with nitrogen in order to reduce electrical resistivity. Compared to the undoped DLC films, the electrical resistivity of nitrogen-doped (N-doped DLC films is decreased by three orders of magnitude. Raman spectroscopy and UV/Vis spectroscopy analyses show the structural transformation in N-doped DLC films that causes the reduction of band gap energy. Contact angle measurement at N-doped DLC films indicates increased hydrophobicity. The results obtained from the cyclic voltammetry measurements with Fe(CN63-/Fe(CN64- redox species exhibit the correlation between the physical properties and electrochemical behavior of DLC films.

  12. Stress reduction of Cu-doped diamond-like carbon films from ab initio calculations

    Directory of Open Access Journals (Sweden)

    Xiaowei Li

    2015-01-01

    Full Text Available Structure and properties of Cu-doped diamond-like carbon films (DLC were investigated using ab initio calculations. The effect of Cu concentrations (1.56∼7.81 at.% on atomic bond structure was mainly analyzed to clarify the residual stress reduction mechanism. Results showed that with introducing Cu into DLC films, the residual compressive stress decreased firstly and then increased for each case with the obvious deterioration of mechanical properties, which was in agreement with the experimental results. Structural analysis revealed that the weak Cu-C bond and the relaxation of both the distorted bond angles and bond lengths accounted for the significant reduction of residual compressive stress, while at the higher Cu concentration the increase of residual stress attributed to the existence of distorted Cu-C structures and the increased fraction of distorted C-C bond lengths.

  13. Effect of Silicon Doping in Cvd Diamond Films from Microcrystalline to Nanocrystalline on WC-Co Substrates

    Science.gov (United States)

    Zhang, Jianguo; Cui, Yuxiao; Shen, Bin; Sun, Fanghong

    2013-12-01

    Si-doped diamond films with various Si concentrations are deposited on WC-Co substrates using HFCVD method, with the mixture of acetone, tetraethoxysilane (TEOS) and hydrogen as the reactant source. A variety of characterizations, including FE-SEM, AFM, Raman, XRD, surface profilometer and Rockwell indentation, are conducted to systematically investigate the influence of Si incorporation on diamond films. As the Si/C ratio from 0% to 5%, the grain size of as-deposited films decreases from 4 μm to about 50 nm, and the surface roughness reduces from Ra 290 nm to Ra 180 nm. Besides, the intensity ratio of I(111)/I(220) varies from 0.57 to 0, indicating the preferred orientation of the nanocrystalline structure in the 5% doped diamond films. The silicon doping is beneficial for the formation of non-diamond carbide phases in the films, according to the Raman spectra. Moreover, the film adhesion is also improved with the increase of Si/C ratio.

  14. 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 .

  15. An optoelectronic study of diamond grown by chemical vapour deposition

    International Nuclear Information System (INIS)

    Hiscock, J.N.

    1999-01-01

    This thesis is concerned with the characterisation of CVD diamond via spectroscopic and electrical investigations. Much of the work concentrates on the identification and the effects of defects and impurities. The bulk of the experimental results are from photoconductivity studies of CVD diamond configured as a detector of ultraviolet light. Other investigations include the annealing of radiation damage in CVD diamond and an electrical characterisation of boron-doped CVD diamond. The characterisation of some group III nitrides forms the short appendix. The work is organised into chapters which are outlined below. Chapter 1 - Introduction: This gives some background to the properties of diamond, its uses, and the different synthesis techniques. Also given is a short review of some of the optical centres in natural and CVD diamond. The kinetics of migration, which is relevant to later chapters is also discussed. Chapter 2 - Experimental Details: This chapter details the experimental techniques and apparatus used in all investigations. An outline of the electronics and data acquisition technique is also presented. Chapter 3 - The Annealing of Radiation Damage: This gives the annealing behaviour of some absorption features in natural and CVD diamond which has been irradiated with electrons. A correlation has been made between the annealing behaviour of two optical centres, and the fast and slow components of a vacancy related centre are explained. Chapter 4 - Electrical characterisation of boron-doped CVD diamond: The boron-doped diamonds studied in this chapter were intended for use as a detector of neutrons. This required a concentration of boron which is large enough for the detection process to occur but low enough for the 'leakage' current to not dominate any induced signal. This electrical characterisation measures the resistivities ( and the temperature dependence ) of the samples and compares this to other work to estimate boron concentrations. Chapter 5 - CVD

  16. Isotopic substitution of boron and carbon in superconducting diamond epilayers grown by MPCVD

    Czech Academy of Sciences Publication Activity Database

    Achatz, P.; Omnès, F.; Ortega, L.; Marcenat, C.; Vacík, Jiří; Hnatowicz, Vladimír; Koster, U.; Jomard, F.; Bustarret, E.

    2010-01-01

    Roč. 19, č. 7 (2010), s. 814-817 ISSN 0925-9635 R&D Projects: GA AV ČR(CZ) KAN400480701 Institutional research plan: CEZ:AV0Z10480505 Keywords : Isotopic effects * Vibrational properties * p-type doping Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.825, year: 2010

  17. Temperature dependent simulation of diamond depleted Schottky PIN diodes

    International Nuclear Information System (INIS)

    Hathwar, Raghuraj; Dutta, Maitreya; Chowdhury, Srabanti; Goodnick, Stephen M.; Koeck, Franz A. M.; Nemanich, Robert J.

    2016-01-01

    Diamond is considered as an ideal material for high field and high power devices due to its high breakdown field, high lightly doped carrier mobility, and high thermal conductivity. The modeling and simulation of diamond devices are therefore important to predict the performances of diamond based devices. In this context, we use Silvaco ® Atlas, a drift-diffusion based commercial software, to model diamond based power devices. The models used in Atlas were modified to account for both variable range and nearest neighbor hopping transport in the impurity bands associated with high activation energies for boron doped and phosphorus doped diamond. The models were fit to experimentally reported resistivity data over a wide range of doping concentrations and temperatures. We compare to recent data on depleted diamond Schottky PIN diodes demonstrating low turn-on voltages and high reverse breakdown voltages, which could be useful for high power rectifying applications due to the low turn-on voltage enabling high forward current densities. Three dimensional simulations of the depleted Schottky PIN diamond devices were performed and the results are verified with experimental data at different operating temperatures

  18. Temperature dependent simulation of diamond depleted Schottky PIN diodes

    Science.gov (United States)

    Hathwar, Raghuraj; Dutta, Maitreya; Koeck, Franz A. M.; Nemanich, Robert J.; Chowdhury, Srabanti; Goodnick, Stephen M.

    2016-06-01

    Diamond is considered as an ideal material for high field and high power devices due to its high breakdown field, high lightly doped carrier mobility, and high thermal conductivity. The modeling and simulation of diamond devices are therefore important to predict the performances of diamond based devices. In this context, we use Silvaco® Atlas, a drift-diffusion based commercial software, to model diamond based power devices. The models used in Atlas were modified to account for both variable range and nearest neighbor hopping transport in the impurity bands associated with high activation energies for boron doped and phosphorus doped diamond. The models were fit to experimentally reported resistivity data over a wide range of doping concentrations and temperatures. We compare to recent data on depleted diamond Schottky PIN diodes demonstrating low turn-on voltages and high reverse breakdown voltages, which could be useful for high power rectifying applications due to the low turn-on voltage enabling high forward current densities. Three dimensional simulations of the depleted Schottky PIN diamond devices were performed and the results are verified with experimental data at different operating temperatures

  19. Temperature dependent simulation of diamond depleted Schottky PIN diodes

    Energy Technology Data Exchange (ETDEWEB)

    Hathwar, Raghuraj; Dutta, Maitreya; Chowdhury, Srabanti; Goodnick, Stephen M. [Department of Electrical Engineering, Arizona State University, Tempe, Arizona 85287-8806 (United States); Koeck, Franz A. M.; Nemanich, Robert J. [Department of Physics, Arizona State University, Tempe, Arizona 85287-8806 (United States)

    2016-06-14

    Diamond is considered as an ideal material for high field and high power devices due to its high breakdown field, high lightly doped carrier mobility, and high thermal conductivity. The modeling and simulation of diamond devices are therefore important to predict the performances of diamond based devices. In this context, we use Silvaco{sup ®} Atlas, a drift-diffusion based commercial software, to model diamond based power devices. The models used in Atlas were modified to account for both variable range and nearest neighbor hopping transport in the impurity bands associated with high activation energies for boron doped and phosphorus doped diamond. The models were fit to experimentally reported resistivity data over a wide range of doping concentrations and temperatures. We compare to recent data on depleted diamond Schottky PIN diodes demonstrating low turn-on voltages and high reverse breakdown voltages, which could be useful for high power rectifying applications due to the low turn-on voltage enabling high forward current densities. Three dimensional simulations of the depleted Schottky PIN diamond devices were performed and the results are verified with experimental data at different operating temperatures.

  20. Atmospheric pressure chemical vapour deposition of boron doped titanium dioxide for photocatalytic water reduction and oxidation.

    Science.gov (United States)

    Carmichael, Penelope; Hazafy, David; Bhachu, Davinder S; Mills, Andrew; Darr, Jawwad A; Parkin, Ivan P

    2013-10-21

    Boron-doped titanium dioxide (B-TiO2) films were deposited by atmospheric pressure chemical vapour deposition of titanium(iv) chloride, ethyl acetate and tri-isopropyl borate on steel and fluorine-doped-tin oxide substrates at 500, 550 and 600 °C, respectively. The films were characterised using powder X-ray diffraction (PXRD), which showed anatase phase TiO2 at lower deposition temperatures (500 and 550 °C) and rutile at higher deposition temperatures (600 °C). X-ray photoelectron spectroscopy (XPS) showed a dopant level of 0.9 at% B in an O-substitutional position. The ability of the films to reduce water was tested in a sacrificial system using 365 nm UV light with an irradiance of 2 mW cm(-2). Hydrogen production rates of B-TiO2 at 24 μL cm(-2) h(-1) far exceeded undoped TiO2 at 2.6 μL cm(-2) h(-1). The B-TiO2 samples were also shown to be active for water oxidation in a sacrificial solution. Photocurrent density tests also revealed that B-doped samples performed better, with an earlier onset of photocurrent.

  1. Boron Doped Multi-walled Carbon Nanotubes as Catalysts for Oxygen Reduction Reaction and Oxygen Evolution Reactionin in Alkaline Media

    International Nuclear Information System (INIS)

    Cheng, Yuanhang; Tian, Yayuan; Fan, Xinzhuang; Liu, Jianguo; Yan, Chuanwei

    2014-01-01

    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

  2. Thin film diamond. Electronic devices for high temperature, high power and high radiation applications

    International Nuclear Information System (INIS)

    Pang, L.Y.S.

    2000-01-01

    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

  3. Real-time study of protein adsorption on thin nanocrystalline diamond

    OpenAIRE

    Grieten, Lars; Janssens, S.D.; Ethirajan, Anitha; Vanden Bon, Natalie; Ameloot, Marcel; Michiels, Luc; Haenen, Ken; Wagner, Patrick

    2011-01-01

    The study of protein adsorption on solid surfaces is interesting for theoretical and practical bio-analytical sensing applications. In this work we combine electrochemical impedance spectroscopy, enzyme linked immunosorbent assay, and fluorescence microscopy with thin boron doped nanocrystalline diamond films to address and study the adsorption behavior of globular proteins (antibodies) on hydrophobic and hydrophilic diamond surfaces. A powerful combination of time resolved impedance spectros...

  4. Semiconductor diamond heater in the Kawai multianvil apparatus: an innovation to generate the lower mantle geotherm

    Science.gov (United States)

    Yoneda, Akira; Xie, Longjian; Tsujino, Noriyoshi; Ito, Eiji

    2014-10-01

    Semiconductor diamond is considered the best heater material to generate ultra-high temperatures in a Kawai cell. In two pioneering studies, a mixture of graphite and amorphous boron (or boron carbide, B4C) was converted to semiconductor diamond in the diamond stability field and was confirmed to generate 2000°C and 3500°C, respectively. Following these works, we synthesized a homemade boron-doped graphite block with fine machinability. With this technical breakthrough, we developed a semiconductor diamond heater in a smaller Kawai-type cell assembly. Here, we report the procedure for making machinable boron-doped graphite, and the performance of the material as a heater in a Kawai cell at 15 GPa using tungsten carbide anvils and at ∼50 GPa using sintered diamond anvils. Furthermore, we present a finite element simulation of the temperature distribution generated by a semiconductor diamond heater, which is much more homogeneous than that generated by a metal heater.

  5. Investigations of different doping concentration of phosphorus and boron into silicon substrate on the variable temperature Raman characteristics

    Science.gov (United States)

    Li, Xiaoli; Ding, Kai; Liu, Jian; Gao, Junxuan; Zhang, Weifeng

    2018-01-01

    Different doped silicon substrates have different device applications and have been used to fabricate solar panels and large scale integrated circuits. The thermal transport in silicon substrates are dominated by lattice vibrations, doping type, and doping concentration. In this paper, a variable-temperature Raman spectroscopic system is applied to record the frequency and linewidth changes of the silicon peak at 520 cm-1 in five chips of silicon substrate with different doping concentration of phosphorus and boron at the 83K to 1473K temperature range. The doping has better heat sensitive to temperature on the frequency shift over the low temperature range from 83K to 300K but on FWHM in high temperature range from 300K to 1473K. The results will be helpful for fundamental study and practical applications of silicon substrates.

  6. 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.

  7. A computational study on the hydrogen adsorption capacity of various lithium-doped boron hydrides.

    Science.gov (United States)

    Pan, Sudip; Giri, Santanab; Chattaraj, Pratim K

    2012-02-05

    An aromatic boron hydride B(3)H(3)(2-) and its various Li/Li(+) doped isomers have been studied at the B3LYP/6-311+G(d) and M06/6-311+G(d) levels of theory to assess their hydrogen storage potential. Different types of interaction energies, reaction enthalpies and reaction electrophilicities associated with the hydrogen adsorption process suggest that B(3)H(3)(2-) itself and some of its Li-decorated analogues may turn out to be effective hydrogen storage material. Nucleus independent chemical shift and conceptual density functional theory based reactivity descriptors lend additional support. The temperature-pressure phase diagram identifies the temperature-pressure zone where the reaction Gibbs free energy for the hydrogen adsorption is negative making it a thermodynamically feasible process. Copyright © 2011 Wiley Periodicals, Inc.

  8. Electronic structure of carbon doped boron nitride nanotubes: a first-principles study.

    Science.gov (United States)

    Kahaly, Mousumi Upadhyay; Waghmare, Umesh V

    2008-08-01

    We determine atomic and electronic structures of arm-chair and zigzag boron nitride nanotubes (BN-NTs) of different diameters using first-principles pseudopotential-based density functional theory calculations. We find that the structure of BN-NTs in bundled form is slightly different from that of the isolated BN-NTs, reflecting on the inter-tube interactions. Effects of carbon doping on the electronic structure of (5,5) and (5,0) BN-NTs are determined: carbon substitution either at B-site, being energetically very stable, or at N-site can yield magnetically polarized semiconducting state, whereas carbon substitution at neighbouring B and N sites yields a non-magnetic insulating structure.

  9. 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

  10. High field magnetic behavior in Boron doped Fe{sub 2}VAl Heusler alloys

    Energy Technology Data Exchange (ETDEWEB)

    Venkatesh, Ch., E-mail: venkyphysicsiitm@gmail.com [Department of Physics, Indian Institute of Technology, Kharagpur (India); DCMP & MS, Tata Institute of Fundamental Research, Mumbai (India); Vasundhara, M., E-mail: vasu.mutta@gmail.com [Materials Science and Technology Division, National Institute for Interdisciplinary Science and Technology, CSIR, Trivandrum 695019 (India); Srinivas, V. [Department of Physics, Indian Institute of Technology, Chennai (India); Rao, V.V. [Cryogenic Engineering Centre, Indian Institute of Technology, Kharagpur (India)

    2016-11-15

    We have investigated the magnetic behavior of Fe{sub 2}VAl{sub 1−x}B{sub x} (x=0, 0.03, 0.06 and 0.1) alloys under high temperature and high magnetic field conditions separately. Although, the low temperature DC magnetization data for the alloys above x>0 show clear magnetic transitions, the zero field cooled (ZFC) and field cooled (FC) curves indicate the presence of spin cluster like features. Further, critical exponent (γ) deduced from the initial susceptibility above the T{sub c}, does not agree with standard models derived for 3 dimensional long range magnetic systems. The deviation in γ values are consistent with the short range magnetic nature of these alloys. We further extend the analysis of magnetic behavior by carrying the magnetization measurements at high temperatures and high magnetic fields distinctly. We mainly emphasize the following observations; (i) The magnetic hysteresis loops show sharp upturns at lower fields even at 900 K for all the alloys. (ii) High temperature inverse susceptibility do not overlap until T=900 K, indicating the persistent short range magnetic correlations even at high temperatures. (iii) The Arrott's plot of magnetization data shows spontaneous moment (M{sub S}) for the x=0 alloy at higher magnetic fields which is absent at lower fields (<50 kOe), while the Boron doped samples show feeble M{sub S} at lower fields. The origin of this short range correlation is due to presence of dilute magnetic heterogeneous phases which are not detected from the X-ray diffraction method. - Highlights: • Short range magnetic character has been confirmed by the critical exponents analysis. • Magnetoresistace is about −14% with non-saturating tendency even at 150 kOe for Fe{sub 2}VAl alloy. • Boron doped Fe{sub 2}VAl alloys show a weak magnetism even at T=900 K.

  11. Growth of boron doped hydrogenated nanocrystalline cubic silicon carbide (3C-SiC) films by Hot Wire-CVD

    Energy Technology Data Exchange (ETDEWEB)

    Pawbake, Amit [School of Energy Studies, Savitribai Phule Pune University, Pune 411 007 (India); Tata Institute of Fundamental Research, Colaba, Mumbai 400 005 (India); Mayabadi, Azam; Waykar, Ravindra; Kulkarni, Rupali; Jadhavar, Ashok [School of Energy Studies, Savitribai Phule Pune University, Pune 411 007 (India); Waman, Vaishali [Modern College of Arts, Science and Commerce, Shivajinagar, Pune 411 005 (India); Parmar, Jayesh [Tata Institute of Fundamental Research, Colaba, Mumbai 400 005 (India); Bhattacharyya, Somnath [Department of Metallurgical and Materials Engineering, IIT Madras, Chennai 600 036 (India); Ma, Yuan‐Ron [Department of Physics, National Dong Hwa University, Hualien 97401, Taiwan (China); Devan, Rupesh; Pathan, Habib [Department of Physics, Savitribai Phule Pune University, Pune 411007 (India); Jadkar, Sandesh, E-mail: sandesh@physics.unipune.ac.in [Department of Physics, Savitribai Phule Pune University, Pune 411007 (India)

    2016-04-15

    Highlights: • Boron doped nc-3C-SiC films prepared by HW-CVD using SiH{sub 4}/CH{sub 4}/B{sub 2}H{sub 6}. • 3C-Si-C films have preferred orientation in (1 1 1) direction. • Introduction of boron into SiC matrix retard the crystallanity in the film structure. • Film large number of SiC nanocrystallites embedded in the a-Si matrix. • Band gap values, E{sub Tauc} and E{sub 04} (E{sub 04} > E{sub Tauc}) decreases with increase in B{sub 2}H{sub 6} flow rate. - Abstract: Boron doped nanocrystalline cubic silicon carbide (3C-SiC) films have been prepared by HW-CVD using silane (SiH{sub 4})/methane (CH{sub 4})/diborane (B{sub 2}H{sub 6}) gas mixture. The influence of boron doping on structural, optical, morphological and electrical properties have been investigated. The formation of 3C-SiC films have been confirmed by low angle XRD, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform infra-red (FTIR) spectroscopy and high resolution-transmission electron microscopy (HR-TEM) analysis whereas effective boron doping in nc-3C-SiC have been confirmed by conductivity, charge carrier activation energy, and Hall measurements. Raman spectroscopy and HR-TEM analysis revealed that introduction of boron into the SiC matrix retards the crystallanity in the film structure. The field emission scanning electron microscopy (FE-SEM) and non contact atomic force microscopy (NC-AFM) results signify that 3C-SiC film contain well resolved, large number of silicon carbide (SiC) nanocrystallites embedded in the a-Si matrix having rms surface roughness ∼1.64 nm. Hydrogen content in doped films are found smaller than that of un-doped films. Optical band gap values, E{sub Tauc} and E{sub 04} decreases with increase in B{sub 2}H{sub 6} flow rate.

  12. 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.

  13. 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.

  14. Cathodoluminescence of Cr-doped diamond-like carbon film by filtered cathodic vacuum arc plasma

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Meng-Wen; Jao, Jui-Yun [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 402, Taiwan (China); Lin, Chun-Chun; Hsieh, Wei-Jen; Yang, Yu-Hsiang [Department of Materials Science and Engineering, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Road, Hsinchu 300, Taiwan (China); Cheng, Li-Shin; Shieu, F.S. [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 402, Taiwan (China); Shih, Han C., E-mail: hcshih@mx.nthu.edu.tw [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 402, Taiwan (China); Department of Materials Science and Engineering, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Road, Hsinchu 300, Taiwan (China); Institute of Materials Science and Nanotechnology, Chinese Culture University, 55 Hwa Kang Road, Yang Ming Shan, Taipei 111, Taiwan (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer The formation of the DLC:Cr films dependent on the flow rates of C{sub 2}H{sub 2}/Ar have been achieved in our FCVA plasma. Black-Right-Pointing-Pointer The amorphous DLC:Cr have high sp{sup 2} content can be completely converted to nanocrystalline Cr{sub 3}C{sub 2}. Black-Right-Pointing-Pointer The effect of doping with Cr is apparently to change the band structure of the DLC and its consequent cathodoluminescence property. - Abstract: Cr doped diamond-like carbon (DLC:Cr) film was synthesized in various flow rates of C{sub 2}H{sub 2}/Ar under a substrate voltage of -50 V at 500 Degree-Sign C by a filtered cathodic vacuum arc plasma. This work has found that the structure of the films was correlated to the flow rate of C{sub 2}H{sub 2}/Ar but the luminescence properties are similar. The cathodoluminescence spectra of DLC:Cr films obtained at 1.9-2.4 eV verifies that the luminescence from the films is in the visible region. The incorporation of Cr into the carbon network results in red emission shifted to 1.99 eV and the orange emission (2.03 eV) also appeared due to the transitions between chromium-related electron levels and {sigma}* states. The peak at 2.10 eV may result from the defects of the structures in DLC:Cr films.

  15. SiV color centers in Si-doped isotopically enriched {sup 12}C and {sup 13}C CVD diamonds

    Energy Technology Data Exchange (ETDEWEB)

    Sedov, Vadim; Bolshakov, Andrey [General Physics Institute, RAS, Moscow (Russian Federation); National Research Nuclear University MEPhI, Moscow (Russian Federation); Boldyrev, Kirill [Institute of Spectroscopy, RAS, Troitsk, Moscow (Russian Federation); Krivobok, Vladimir; Nikolaev, Sergei [Lebedev Physical Institute, RAS, Moscow (Russian Federation); Khomich, Alex [Institute of Radio Engineering and Electronics, RAS, Fryazino (Russian Federation); Khomich, Andrew [General Physics Institute, RAS, Moscow (Russian Federation); Institute of Radio Engineering and Electronics, RAS, Fryazino (Russian Federation); Krasilnikov, Anatoly [Institution ' ' ProjectCenter ITER' ' , Moscow (Russian Federation); Ralchenko, Victor [General Physics Institute, RAS, Moscow (Russian Federation); National Research Nuclear University MEPhI, Moscow (Russian Federation); Harbin Institute of Technology, Harbin (China)

    2017-11-15

    The effect of isotopic modification of diamond lattice on photoluminescence (PL) and optical absorption spectra of ensembles of SiV{sup -} centers was studied. Thin epitaxial diamond layers were grown by a microwave plasma CH{sub 4}/H{sub 2} mixtures using methane enriched to 99.96% for either {sup 12}C or {sup 13}C isotopes, while the Si doping was performed by adding a small percentage of silane SiH{sub 4} into the plasma. Temperature dependent SiV{sup -} ZPL spectra in absorption were measured at 3-80 K to monitor the evolution of the ZPL fine structure. It is found that the SiV{sup -} ZPL at 736.9 nm observed in PL for {sup 12}C diamond at T = 5 K, exhibits a blue shift of 1.78 meV, to 736.1 nm in {sup 13}C diamond matrix. Narrow ZPL with the width (FWHM) of 0.09 meV (21 GHz) was measured in absorption spectra at T = 3-30 K in the Si-doped {sup 13}C diamond. Besides the charged SiV{sup -} center, the absorption of the neutral SiV{sup 0} defect at 946 nm wavelength has also been detected. From changes observed in SiV{sup -} phonon band structure in PL with isotopic modification, the band at 64 meV was confirmed to be a local vibration mode (LVM) involving a Si atom. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Boron doping: B/H/C/O gas-phase chemistry; H atom density dependences on pressure and wire temperature; puzzles regarding the gas-surface mechanism

    International Nuclear Information System (INIS)

    Mankelevich, Yuri A.; Ashfold, Michael N.R.; Comerford, Dane W.; Ma Jie; Richley, James C.

    2011-01-01

    Experimental and modeling studies of the gas-phase chemistry occurring in dilute, hot filament (HF) activated B 2 H 6 /CH 4 /H 2 gas mixtures appropriate for growth of boron-doped diamond are reported. The results of two-dimensional modeling of heat and mass transfer processes and the B/H/C chemistry prevailing in such HF activated gas mixtures (supplemented by reactions involving trace O 2 present as air impurity in the process gas mixture) are discussed and compared with measurements of B atom densities as functions of the hot wire temperature T w and distance from the wire. Most of the B 2 H 6 molecules that diffuse from the cool, near-wall regions into the hot, near wire region are thermally decomposed (yielding two BH 3 molecules as primary products) and then converted into various 'active' B-containing species like B, BH and BH 2 - some of which are able to accommodate into the growing diamond film. H-shifting reactions BH x + H ↔ BH x-1 + H 2 enable rapid inter-conversion between the various BH x (x = 0-3) species and the BH x source is limited by diffusional transfer of B 2 H 6 . H atoms play several key roles - e.g. activating the process gas mixture, and driving inter-conversions between the various H x B y C z O z' species. We show that the T w and gas pressure dependences of the H atom production rate (by H 2 dissociation on the HF surface) can be accommodated by a simple gas-surface reaction model.

  17. Analysis of laser doping of silicon using different boron dopant sources

    Energy Technology Data Exchange (ETDEWEB)

    Prathap, P., E-mail: pathiprathap@gmail.com [InESS, CNRS-UdS, Strasbourg Cedex-2 (France); National Physical Laboratory, KS Krishnan Road, New Delhi 110012 (India); Bartringer, J.; Slaoui, A. [InESS, CNRS-UdS, Strasbourg Cedex-2 (France)

    2014-05-01

    Implementation of selective emitter that decouples the requirements for front doping and metallization leads to improve the efficiency of crystalline silicon solar cells. Formation of such an efficient selective emitter using a laser beam with a suitable wavelength is an attractive method. The present work focuses on the analysis of laser doping of boron using different finite sources such as borosilicate glass (BSG) deposited by PECVD, spin-on solution and BCl{sub 3} gas source. KrF excimer laser (248 nm) was used for the selective doping. The surface dopant concentration and depth, as measured using SIMS, were controlled by variation of the laser fluence, pulse number and dopant source thickness. Depending on the type of BSG source, sheet resistance close to 20 Ω/sq was achieved at the laser fluences in the range, 2.5–5 J/cm{sup 2}. The PECVD-BSG layers with a relatively higher thickness resulted in a lower sheet resistance of 20 Ω/sq with a junction of depth of ∼1 μm at a moderate laser fluence of 2.5 J/cm{sup 2}. In the case of BSG deposited by spin-on source, a deeper junction of depth of ∼2.7 μm with a plateau profile of 1 μm was formed at a laser fluence of 3.1 J/cm{sup 2} that resulted in a lower sheet resistance of ∼31 Ω/sq. Redistribution of the dopant with pulse repetition was observed for the BSG deposited by BCl{sub 3} gas source. Pulse repetition at relatively lower laser fluences (>threshold energy) resulted in the best electrical results in combination with a limited laser induced damage in the silicon crystal. Also, multiple laser annealing resulted in redistribution of the dopant profiles in terms of enhanced junction depth.

  18. Analysis of laser doping of silicon using different boron dopant sources

    Science.gov (United States)

    Prathap, P.; Bartringer, J.; Slaoui, A.

    2014-05-01

    Implementation of selective emitter that decouples the requirements for front doping and metallization leads to improve the efficiency of crystalline silicon solar cells. Formation of such an efficient selective emitter using a laser beam with a suitable wavelength is an attractive method. The present work focuses on the analysis of laser doping of boron using different finite sources such as borosilicate glass (BSG) deposited by PECVD, spin-on solution and BCl3 gas source. KrF excimer laser (248 nm) was used for the selective doping. The surface dopant concentration and depth, as measured using SIMS, were controlled by variation of the laser fluence, pulse number and dopant source thickness. Depending on the type of BSG source, sheet resistance close to 20 Ω/sq was achieved at the laser fluences in the range, 2.5-5 J/cm2. The PECVD-BSG layers with a relatively higher thickness resulted in a lower sheet resistance of 20 Ω/sq with a junction of depth of ∼1 μm at a moderate laser fluence of 2.5 J/cm2. In the case of BSG deposited by spin-on source, a deeper junction of depth of ∼2.7 μm with a plateau profile of 1 μm was formed at a laser fluence of 3.1 J/cm2 that resulted in a lower sheet resistance of ∼31 Ω/sq. Redistribution of the dopant with pulse repetition was observed for the BSG deposited by BCl3 gas source. Pulse repetition at relatively lower laser fluences (>threshold energy) resulted in the best electrical results in combination with a limited laser induced damage in the silicon crystal. Also, multiple laser annealing resulted in redistribution of the dopant profiles in terms of enhanced junction depth.

  19. One-step synthesis of shell/core structural boron and nitrogen co-doped graphitic carbon/nanodiamond as efficient electrocatalyst for the oxygen reduction reaction in alkaline media

    International Nuclear Information System (INIS)

    Liu, Xiaoxu; Wang, Yanhui; Dong, Liang; Chen, Xi; Xin, Guoxiang; Zhang, Yan; Zang, Jianbing

    2016-01-01

    Shell/core structural boron and nitrogen co-doped graphitic carbon/nanodiamond (BN-C/ND) non-noble metal catalyst has been synthesized by a simple one-step heat-treatment of the mixture with nanodiamond, melamine, boric acid and FeCl 3 . In the process of the surface graphitization of nanodiamond with catalysis by FeCl 3 , B and N atoms from the decomposition of boric acid and melamine were directly introduced into the graphite lattice to form B, N co-doped graphitic carbon shell, while the core still retained the diamond structure. Electrochemical measurements of the BN-C/ND catalyst show much higher electrocatalytic activities towards oxygen reduction reaction (ORR) in alkaline medium than its analogues doped with B or N alone (B-C/ND or N-C/ND). The high catalytic activity of BN-C/ND is attributed to the synergetic effect caused by co-doping of C/ND with B and N. Meanwhile, the BN-C/ND exhibits an excellent electrochemical stability due to the special shell/core structure. There is almost no alteration occurred in the cyclic voltammetry measurements for BN-C/ND before and after 5000 cycles. All experimental results prove that the BN-C/ND may be exploited as a potentially efficient and inexpensive non-noble metal cathode catalyst for ORR to substitute Pt-based catalysts in fuel cells.

  20. Preparation of boron-doped porous titania networks containing gold nanoparticles with enhanced visible-light photocatalytic activity.

    Science.gov (United States)

    Wang, Xingdong; Blackford, Mark; Prince, Kathryn; Caruso, Rachel A

    2012-01-01

    The ability to decrease the electron/hole recombination rate, and decrease the band gap of titania to allow photoactivity on irradiation with visible light is attracting more and more attention. Here, boron doping of the titania, the deposition of gold nanoparticles, along with a meso-macroporous structure were obtained using a facile agarose gel templating process combined with sol-gel chemistry. The Au/B/TiO(2) nanocomposites were characterized using SEM, TEM, XRD, N(2) gas sorption, diffuse UV-vis, photoluminescence, and SIMS. The photocatalytic activity was assessed by degradation of an organic probe molecule (methylene blue) under visible light (λ > 420 nm). The resulting materials achieved photocatalytic activities up to 50% greater than the commercial Degussa P25 under visible light. The enhancement in photocatalytic activity was primarily attributed to the decrease in band gap as a result of the boron doping and its influence on the anatase to rutile phase formation: The doped materials were highly crystalline and an optimum anatase to rutile ratio (3:1) was obtained with 0.25 wt % boron in the sample calcined at 650 °C. In addition, the presence of the gold nanoparticles decreased recombination between the photoexcited electrons and holes, which further improved the photocatalytic activity. © 2012 American Chemical Society

  1. The processing of heteroepitaxial thin-film diamond for electronic applications

    International Nuclear Information System (INIS)

    McGrath, J.

    1998-09-01

    Thin film diamond is of particular interest because of its wide applicability, including its potential use in high temperature electronics. This thesis describes a study of some of the processing stages required to exploit thin film diamond as an electronic device. Initial experiments were carried out to optimise bi-metallic contact schemes on orientated diamond film using electrical measurements and chemical analysis. Temperature stability was also investigated and it was concluded that the most favourable ohmic contact scheme is aluminium-on-titanium. Further electrical measurements confirmed that the contribution of resistance made by the contacts themselves to the metal/diamond/metal system overall was acceptably low, specifically 6 Ω.cm 2 for an undoped diamond system and less than 3 x 10 -6 Ω.cm 2 for boron doped diamond. To improve the as-grown resistivity of diamond films, an oxygen/argon plasma etch process was applied. The input parameters of the plasma system were optimised to give the maximum achievable resistivity of 4 x 10 11 Ω.cm. This was attained using a statistical design procedure via analysis of resistivity and etch rate outputs. Having optimised post growth treatment and contact metallisation, undoped and doped orientated diamond films were characterised via voltage and temperature dependencies. It was concluded that the dominant charge transport mechanisms for undoped diamond, nitrogen and boron doped diamond were variable range hopping at low temperatures up to 523 K and grain boundary effects. At higher temperatures, valence or impurity band conduction appeared to be the probable mechanisms with activation energies of 0.23 eV for nitrogen doped diamond and 0.08 eV for boron doped diamond. Preliminary experiments electrical properties of diamond and initial results suggested the presence of a high density of recombination centres. The final stage of experimental research initiated a study of direct electron beam writing lithography to

  2. Highly photostable NV centre ensembles in CVD diamond produced by using N2O as the doping gas

    Science.gov (United States)

    Tallaire, A.; Mayer, L.; Brinza, O.; Pinault-Thaury, M. A.; Debuisschert, T.; Achard, J.

    2017-10-01

    High density Nitrogen-Vacancy (NV) centre ensembles incorporated in plasma assisted chemical vapour deposition (CVD) diamond are crucial to the development of more efficient sensing devices that use the properties of luminescent defects. Achieving high NV doping with N2 as the dopant gas source during diamond growth is, however, plagued by the formation of macroscopic and point defects that quench luminescence. Moreover, such NVs are found to exhibit poor photostability under high laser powers. Although this effect can be harnessed to locally and durably switch off NV luminescence for data storage, it is usually undesirable for most applications. In this work, the use of N2O as an alternative doping source is proposed. Much higher amounts of the doping gas can be added without significantly generating defects, which allows the incorporation of perfectly photostable and higher density NV ensembles. This effect is believed to be related to the lower dissociation energy of the N2O molecule together with the beneficial effect of the presence of a low and controlled amount of oxygen near the growing surface.

  3. Continuous growth of low-temperature Si epitaxial layer with heavy phosphorous and boron doping using photoepitaxy

    International Nuclear Information System (INIS)

    Yamazaki, T.; Minakata, H.; Ito, T.

    1990-01-01

    The authors grew p + -n + silicon epitaxial layers, heavily doped with phosphorus and boron, continuously at 650 degrees C using low-temperature photoepitaxy. Then N + photoepitaxial layer with a phosphorus concentration above 10 17 cm -3 grown on p - substrate shows high-density surface pits, and as a result, poor crystal quality. However, when this n + photoepitaxial layer is grown continuously on a heavily boron-doped p + photoepitaxial layer, these surface pits are drastically decreased, disappearing completely above a hole concentration of 10 19 cm -3 in the p + photoepitaxial layer. The phosphorus activation ratio and electron Hall mobility in the heavily phosphorus-doped n + photoexpitaxial layer were also greatly improved. The authors investigated the cause of the surface pitting using a scanning transmission electron microscope, secondary ion mass spectroscopy, and energy-dispersive x-ray spectroscopy. They characterized the precipitation of phosphorus atoms on the crystal surface at the initial stage of the heavily phosphorus-doped n + photoexpitaxial layer growth

  4. Properties of silicon nanocrystals with boron and phosphorus doping fabricated via silicon rich oxide and silicon dioxide bilayers

    Science.gov (United States)

    Chien-Jen Yang, Terry; Nomoto, Keita; Puthen-Veettil, Binesh; Lin, Ziyun; Wu, Lingfeng; Zhang, Tian; Jia, Xuguang; Conibeer, Gavin; Perez-Wurfl, Ivan

    2017-07-01

    Effects of boron and phosphorus doping on the structural, electrical, and optical properties of silicon nanocrystals in superlattice thin films were investigated. Silicon nanocrystals were fabricated via magnetron sputtering of stoichiometric silicon rich oxide and silicon dioxide bilayers followed by high temperature annealing at 1100 degrees Celsius. The characterization techniques used include: high-resolution transmission electron microscopy with energy filtering, grazing incidence x-ray diffraction, Raman, photoluminescence, and photothermal deflection spectroscopy, as well as electrical measurements. Results showed that phosphorus doping causes the loss of the bilayer structure and an increase in the average size of the silicon nanocrystals due to softening of the silicon dioxide matrix during post-sputter annealing. The result was a decrease in quantum confinement and a redshift in photoluminescence spectrum with an absorption profile similar to crystalline silicon. The undoped (intrinsic) sample maintained its bilayer structure and displayed stronger quantum confinement with higher photoluminescence peak energy and higher absorption coefficient. In-between, the boron doped sample was more similar structurally to the intrinsic sample, although merging between bilayers resulted in an extensive silicon nanocrystalline network. Optically, it displayed different effects due to photoluminescence quenching and free carrier absorption. Finally, both doped samples exhibited a decrease in electrical resistivity.

  5. Osmium Atoms and Os2 Molecules Move Faster on Selenium-Doped Compared to Sulfur-Doped Boronic Graphenic Surfaces.

    Science.gov (United States)

    Barry, Nicolas P E; Pitto-Barry, Anaïs; Tran, Johanna; Spencer, Simon E F; Johansen, Adam M; Sanchez, Ana M; Dove, Andrew P; O'Reilly, Rachel K; Deeth, Robert J; Beanland, Richard; Sadler, Peter J

    2015-07-28

    We deposited Os atoms on S- and Se-doped boronic graphenic surfaces by electron bombardment of micelles containing 16e complexes [Os(p-cymene)(1,2-dicarba-closo-dodecarborane-1,2-diselenate/dithiolate)] encapsulated in a triblock copolymer. The surfaces were characterized by energy-dispersive X-ray (EDX) analysis and electron energy loss spectroscopy of energy filtered TEM (EFTEM). Os atoms moved ca. 26× faster on the B/Se surface compared to the B/S surface (233 ± 34 pm·s(-1) versus 8.9 ± 1.9 pm·s(-1)). Os atoms formed dimers with an average Os-Os distance of 0.284 ± 0.077 nm on the B/Se surface and 0.243 ± 0.059 nm on B/S, close to that in metallic Os. The Os2 molecules moved 0.83× and 0.65× more slowly than single Os atoms on B/S and B/Se surfaces, respectively, and again markedly faster (ca. 20×) on the B/Se surface (151 ± 45 pm·s(-1) versus 7.4 ± 2.8 pm·s(-1)). Os atom motion did not follow Brownian motion and appears to involve anchoring sites, probably S and Se atoms. The ability to control the atomic motion of metal atoms and molecules on surfaces has potential for exploitation in nanodevices of the future.

  6. Electrochemical treatment of domestic wastewater using boron-doped diamond and nanostructured amorphous carbon electrodes.

    Science.gov (United States)

    Daghrir, Rimeh; Drogui, Patrick; Tshibangu, Joel; Delegan, Nazar; El Khakani, My Ali

    2014-05-01

    The performance of the electrochemical oxidation process for efficient treatment of domestic wastewater loaded with organic matter was studied. The process was firstly evaluated in terms of its capability of producing an oxidant agent (H2O2) using amorphous carbon (or carbon felt) as cathode, whereas Ti/BDD electrode was used as anode. Relatively high concentrations of H2O2 (0.064 mM) was produced after 90 min of electrolysis time, at 4.0 A of current intensity and using amorphous carbon at the cathode. Factorial design and central composite design methodologies were successively used to define the optimal operating conditions to reach maximum removal of chemical oxygen demand (COD) and color. Current intensity and electrolysis time were found to influence the removal of COD and color. The contribution of current intensity on the removal of COD and color was around 59.1 and 58.8%, respectively, whereas the contribution of treatment time on the removal of COD and color was around 23.2 and 22.9%, respectively. The electrochemical treatment applied under 3.0 A of current intensity, during 120 min of electrolysis time and using Ti/BDD as anode, was found to be the optimal operating condition in terms of cost/effectiveness. Under these optimal conditions, the average removal rates of COD and color were 78.9 ± 2 and 85.5 ± 2 %, whereas 70% of total organic carbon removal was achieved.

  7. RETRACTED: Growth of boron-doped diamond nanoclusters using the HFCVD technique

    Science.gov (United States)

    Azadfar, P.; Ghoranneviss, M.; Elahi, S. M.; Farhadyar, N.; Salar Elahi, A.

    2015-04-01

    This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Principal Editor. After a thorough investigation, the Editor has concluded that the review process for this article was compromised. The acceptance was based on information from one reviewer report that was submitted from an email account provided to the journal as a suggested reviewer during the submission of the article. Although purportedly a real reviewer account, the Editor has concluded that this was not of an appropriate, independent reviewer. This manipulation of the peer-review process represents a clear violation of the fundamentals of peer review, our publishing policies, and publishing ethics standards. Apologies are offered to the reviewer whose identity was assumed and to the readers of the journal that this deception was not detected during the submission process.

  8. Electrochemical Protein Cleavage in a Microfluidic Cell with Integrated Boron Doped Diamond Electrodes

    NARCIS (Netherlands)

    van den Brink, Floris T G; Zhang, Tao; Ma, Liwei; Bomer, Johan; Odijk, Mathieu; Olthuis, Wouter; Permentier, Hjalmar P; Bischoff, Rainer; van den Berg, Albert

    2016-01-01

    Specific electrochemical cleavage of peptide bonds at the C-terminal side of tyrosine and tryptophan generates peptides amenable to liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis for protein identification. To this end we developed a microfluidic electrochemical cell of 160 nL

  9. Electrochemical protein cleavage in a microfluidic cell with integrated boron doped diamond electrodes

    NARCIS (Netherlands)

    van den Brink, Floris Teunis Gerardus; Zhang, Tao; Ma, Liwei; Bomer, Johan G.; Odijk, Mathieu; Olthuis, Wouter; Permentier, Hjalmar P.; Bischoff, Rainer; van den Berg, Albert

    2016-01-01

    Specific electrochemical cleavage of peptide bonds at the C-terminal side of tyrosine and tryptophan generates peptides amenable to liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis for protein identification. To this end we developed a microfluidic electrochemical cell of 160 nL

  10. Rich interfacial chemistry and properties of carbon-doped hexagonal boron nitride nanosheets revealed by electronic structure calculations

    Science.gov (United States)

    Xie, Wei; Tamura, Takahiro; Yanase, Takashi; Nagahama, Taro; Shimada, Toshihiro

    2018-04-01

    The effect of C doping to hexagonal boron nitride (h-BN) to its electronic structure is examined by first principles calculations using the association from π-electron systems of organic molecules embedded in a two-dimensional insulator. In a monolayered carbon-doped structure, odd-number doping with carbon atoms confers metallic properties with different work functions. Various electronic interactions occur between two layers with odd-number carbon substitution. A direct sp3 covalent chemical bond is formed when C replaces adjacent B and N in different layers. A charge transfer complex between layers is found when C replaces B and N in the next-neighboring region, which results in narrower band gaps (e.g., 0.37 eV). Direct bonding between C and B atoms is found when two C atoms in different layers are at a certain distance.

  11. Electrochemical detection of L-cysteine using a boron-doped carbon nanotube-modified electrode

    International Nuclear Information System (INIS)

    Deng Chunyan; Chen Jinhua; Chen Xiaoli; Wang Mengdong; Nie Zhou; Yao Shouzhuo

    2009-01-01

    A boron-doped carbon nanotube (BCNT)-modified glassy carbon (GC) electrode was constructed for the detection of L-cysteine (L-CySH). The electrochemical behavior of BCNTs in response to L-cysteine oxidation was investigated. The response current of L-CySH oxidation at the BCNT/GC electrode was obviously higher than that at the bare GC electrode or the CNT/GC electrode. This finding may be ascribed to the excellent electrochemical properties of the BCNT/GC electrode. Moreover, on the basis of this finding, a determination of L-CySH at the BCNT/GC electrode was carried out. The effects of pH, scan rate and interferents on the response of L-CySH oxidation were investigated. Under the optimum experimental conditions, the detection response for L-CySH on the BCNT/GC electrode was fast (within 7 s). It was found to be linear from 7.8 x 10 -7 to 2 x 10 -4 M (r = 0.998), with a high sensitivity of 25.3 ± 1.2 nA mM -1 and a low detection limit of 0.26 ± 0.01 μM. The BCNT/GC electrode exhibited high stability and good resistance against interference by other oxidizable amino acids (tryptophan and tyrosine)

  12. First-principle approach based bandgap engineering for cubic boron nitride doped with group IIA elements

    Science.gov (United States)

    Li, Yubo; Wang, Pengtao; Hua, Fei; Zhan, Shijie; Wang, Xiaozhi; Luo, Jikui; Yang, Hangsheng

    2018-03-01

    Electronic properties of cubic boron nitride (c-BN) doped with group IIA elements were systematically investigated using the first principle calculation based on density functional theory. The electronic bandgap of c-BN was found to be narrowed when the impurity atom substituted either the B (IIA→B) or the N (IIA→N) atom. For IIA→B, a shallow accept level degenerated into valence band (VB); while for IIA→N, a shallow donor level degenerated conduction band (CB). In the cases of IIBe→N and IIMg→N, deep donor levels were also induced. Moreover, a zigzag bandgap narrowing pattern was found, which is in consistent with the variation pattern of dopants' radius of electron occupied outer s-orbital. From the view of formation energy, the substitution of B atom under N-rich conditions and the substitution of N atom under B-rich conditions were energetically favored. Our simulation results suggested that Mg and Ca are good candidates for p-type dopants, and Ca is the best candidate for n-type dopant.

  13. First-principle approach based bandgap engineering for cubic boron nitride doped with group IIA elements

    Directory of Open Access Journals (Sweden)

    Yubo Li

    2018-03-01

    Full Text Available Electronic properties of cubic boron nitride (c-BN doped with group IIA elements were systematically investigated using the first principle calculation based on density functional theory. The electronic bandgap of c-BN was found to be narrowed when the impurity atom substituted either the B (IIA→B or the N (IIA→N atom. For IIA→B, a shallow accept level degenerated into valence band (VB; while for IIA→N, a shallow donor level degenerated conduction band (CB. In the cases of IIBe→N and IIMg→N, deep donor levels were also induced. Moreover, a zigzag bandgap narrowing pattern was found, which is in consistent with the variation pattern of dopants’ radius of electron occupied outer s-orbital. From the view of formation energy, the substitution of B atom under N-rich conditions and the substitution of N atom under B-rich conditions were energetically favored. Our simulation results suggested that Mg and Ca are good candidates for p-type dopants, and Ca is the best candidate for n-type dopant.

  14. Comparison of the influence of boron and aluminium doping on the material properties of electrochemically deposited ZnO films

    Energy Technology Data Exchange (ETDEWEB)

    Calnan, Sonya [Helmholtz-Zentrum für Materialien und Energie GmbH, Hahn-Meitner Platz 1, 14109 Berlin (Germany); Riedel, Wiebke; Gledhill, Sophie [Helmholtz-Zentrum für Materialien und Energie GmbH, Hahn-Meitner Platz 1, 14109 Berlin (Germany); Fachbereich Physik, Freie Universitaet Berlin, Arnimallee 14, 14195 Berlin (Germany); Stannowski, Bernd [Helmholtz-Zentrum für Materialien und Energie GmbH, Hahn-Meitner Platz 1, 14109 Berlin (Germany); Lux-Steiner, Martha Ch. [Helmholtz-Zentrum für Materialien und Energie GmbH, Hahn-Meitner Platz 1, 14109 Berlin (Germany); Fachbereich Physik, Freie Universitaet Berlin, Arnimallee 14, 14195 Berlin (Germany); Schlatmann, Rutger [Helmholtz-Zentrum für Materialien und Energie GmbH, Hahn-Meitner Platz 1, 14109 Berlin (Germany); Fachbereich 1 Ingenieurwissenschaften I, University of Applied Science (HTW) Berlin, Wilhelminenhofstraße 75 A, 12459 Berlin (Germany)

    2015-11-02

    The effect of varying the boron and aluminium content of the starting electrolyte for extrinsically doped ZnO films grown on SnO{sub 2}:F substrates by electrochemical deposition was investigated. The ZnO:B film surface was characterized by grains with mainly hexagonal faces exposed while the exposed faces of the ZnO:Al grains were rectangular. Whereas a B{sup 3+}/Zn{sup 2+} ratio of up to 10 at.% in the electrolyte had no significant effect on the crystalline structure of the ZnO films, an Al{sup 3+}/Zn{sup 2+} ratio above 0.25 at.% increased the disorder in the crystalline structure. All the boron doped films exhibit a strong E{sub 2}-high Raman mode related to wurtzite ZnO structure but this peak was much weaker for ZnO:Al and diminished with increasing Al incorporation in the films. Exposing the films to ultra-violet light reduced their effective sheet resistance from values beyond measurement range to values between 40 and 5000 kΩ/sq for film thicknesses of 200–550 nm. Inspection of the optical spectra near the bandgap edge and the plasma edge in the mid infrared range, showed that the Al-doping resulted in a higher carrier concentration ~ 10{sup 20} cm{sup −3} than B-doping. X-ray electron spectroscopy showed that the dopant efficiency was limited by the absence of dopant atoms near the surface of all the ZnO:B films and of the lightly doped ZnO:Al and, by the formation of aluminium oxide at the surface of the more highly doped ZnO:Al films. - Highlights: • Crystalline ZnO grown by electrochemical deposition. • Comparison of influence of H{sub 3}BO{sub 3} and Al(NO{sub 3}){sub 3} as dopant sources. • Different ZnO crystalline orientation for Al and boron doping. • Film surface chemical composition suppressed electrical conductivity.

  15. Studies on the oxygen precipitation in highly boron doped silicon; Untersuchungen zur Sauerstoffausscheidung in hoch bordotiertem Silicium

    Energy Technology Data Exchange (ETDEWEB)

    Zschorsch, Markus

    2007-12-14

    The aim of this thesis was the getting of new knowledge on the elucidation of the oxygen precipitation in highly doped silicon. In the study of the early phases of the oxygen precipitation boron-oxygen complexes and their kinetics could be indirectly detected. These arise already during the cooling of the crystal and can be destroyed by subsequent temperature processes. The formation of the here as BO assumed species during the cooling after the silicon crystal fabrication could be numerically reproduced. Furthermore the study of early precipitation phases by means of neutron small angle scattering a maximum of the oxygen precipitation at {rho}=9 m{omega}cm. It could be shown that the decreasing of this at increasing boron concentration can be most probably reduced to boron precipitations. Furthermore it could be shown that after a tempering time of 24 hours at 700 C in silicon with {rho}=9 m{omega}cm platelet-shaped precipitates form. By the study of the precipitate growth could be shown that also in this phase the oxygen precipitation in silicon is strongest with a specific resistance of {rho}=9 m{omega}cm. By means of FTIR spectroscopy a new absorption band at a wave number of 1038 cm{sup -1} was found, which could be assigned to a boron species. By different experiments it is considered as probable that at this species it deals with BI respectively B{sub 2}I complexes.

  16. Investigation of charges carrier density in phosphorus and boron doped SiN{sub x}:H layers for crystalline silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Paviet-Salomon, B., E-mail: bertrand.paviet-salomon@epfl.ch [Commissariat à l’Énergie Atomique (CEA), Laboratoire d’Innovation pour les Technologies des Énergies Nouvelles et les nanomatériaux (LITEN), Institut National de l’Énergie Solaire - INES, 50 avenue du Lac Léman, 73377 Le Bourget du Lac (France); Gall, S. [Commissariat à l’Énergie Atomique (CEA), Laboratoire d’Innovation pour les Technologies des Énergies Nouvelles et les nanomatériaux (LITEN), Institut National de l’Énergie Solaire - INES, 50 avenue du Lac Léman, 73377 Le Bourget du Lac (France); Slaoui, A. [Institut de l’Électronique du Solide et des Systèmes (InESS), Unité Mixte de Recherche 7163 Centre National de la Recherche Scientifique-Université de Strasbourg (UMR 7163 CNRS-UDS), 23 rue du Loess, BP 20 CR, 67037 Strasbourg (France)

    2013-05-15

    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 (Q{sub fix}) and the effective lifetimes (τ{sub eff}) of phosphorus (P) and boron (B) doped silicon nitride layers deposited by plasma-enhanced chemical vapour deposition. P-doped layers exhibit a higher τ{sub eff} than standard undoped layers. In contrast, B-doped layers exhibit lower τ{sub eff}. A strong Q{sub fix} 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.

  17. First-principles investigations of the magnetic properties of graphite boron nitride sheet induced by Fe doping.

    Science.gov (United States)

    Deng, Xiaohui; Wang, Wenwei; Zhang, Dengyu; Lu, Wei; Fan, Bingbing

    2010-05-26

    The first-principles spin polarization method is used to investigate the magnetic properties of graphite boron nitride (g-BN) sheet induced by Fe doping. We find that a nitrogen or boron atom substituted by Fe can induce a magnetic moment. From standard Mulliken population analysis, we also find that the magnetic moment is mainly dominated by Fe 3d states. Using Heisenberg exchange coupling theory, we study the exchange coupling mechanisms by constructing two-Fe centers in g-BN. The results show the presence of relatively strong exchange coupling for two-Fe substituted two-B atoms and the coupling is ferromagnetic. For the case of two-Fe substituted two-N atoms, the coupling is antiferromagnetic and the exchange coupling is very weak. The paper enriches recent molecular magnetic investigations.

  18. Ti-doped hydrogenated diamond like carbon coating deposited by hybrid physical vapor deposition and plasma enhanced chemical vapor deposition

    Science.gov (United States)

    Lee, Na Rae; Sle Jun, Yee; Moon, Kyoung Il; Sunyong Lee, Caroline

    2017-03-01

    Diamond-like carbon films containing titanium and hydrogen (Ti-doped DLC:H) were synthesized using a hybrid technique based on physical vapor deposition (PVD) and plasma enhanced chemical vapor deposition (PECVD). The film was deposited under a mixture of argon (Ar) and acetylene gas (C2H2). The amount of Ti in the Ti-doped DLC:H film was controlled by varying the DC power of the Ti sputtering target ranging from 0 to 240 W. The composition, microstructure, mechanical and chemical properties of Ti-doped DLC:H films with varying Ti concentrations, were investigated using Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), nano indentation, a ball-on-disk tribometer, a four-point probe system and dynamic anodic testing. As a result, the optimum composition of Ti in Ti-doped DLC:H film using our hybrid method was found to be a Ti content of 18 at. %, having superior electrical conductivity and high corrosion resistance, suitable for bipolar plates. Its hardness value was measured to be 25.6 GPa with a low friction factor.

  19. Gas Permeation, Mechanical Behavior and Cytocompatibility of Ultrathin Pure and Doped Diamond-Like Carbon and Silicon Oxide Films

    Directory of Open Access Journals (Sweden)

    Juergen M. Lackner

    2013-12-01

    Full Text Available Protective ultra-thin barrier films gather increasing economic interest for controlling permeation and diffusion from the biological surrounding in implanted sensor and electronic devices in future medicine. Thus, the aim of this work was a benchmarking of the mechanical oxygen permeation barrier, cytocompatibility, and microbiological properties of inorganic ~25 nm thin films, deposited by vacuum deposition techniques on 50 µm thin polyetheretherketone (PEEK foils. Plasma-activated chemical vapor deposition (direct deposition from an ion source was applied to deposit pure and nitrogen doped diamond-like carbon films, while physical vapor deposition (magnetron sputtering in pulsed DC mode was used for the formation of silicon as well as titanium doped diamond-like carbon films. Silicon oxide films were deposited by radio frequency magnetron sputtering. The results indicate a strong influence of nanoporosity on the oxygen transmission rate for all coating types, while the low content of microporosity (particulates, etc. is shown to be of lesser importance. Due to the low thickness of the foil substrates, being easily bent, the toughness as a measure of tendency to film fracture together with the elasticity index of the thin films influence the oxygen barrier. All investigated coatings are non-pyrogenic, cause no cytotoxic effects and do not influence bacterial growth.

  20. Rhenium Alloys as Ductile Substrates for Diamond Thin-Film Electrodes.

    Science.gov (United States)

    Halpern, Jeffrey M; Martin, Heidi B

    2014-02-01

    Molybdenum-rhenium (Mo/Re) and tungsten-rhenium (W/Re) alloys were investigated as substrates for thin-film, polycrystalline boron-doped diamond electrodes. Traditional, carbide-forming metal substrates adhere strongly to diamond but lose their ductility during exposure to the high-temperature (1000°C) diamond, chemical vapor deposition environment. Boron-doped semi-metallic diamond was selectively deposited for up to 20 hours on one end of Mo/Re (47.5/52.5 wt.%) and W/Re (75/25 wt.%) alloy wires. Conformal diamond films on the alloys displayed grain sizes and Raman signatures similar to films grown on tungsten; in all cases, the morphology and Raman spectra were consistent with well-faceted, microcrystalline diamond with minimal sp 2 carbon content. Cyclic voltammograms of dopamine in phosphate-buffered saline (PBS) showed the wide window and low baseline current of high-quality diamond electrodes. In addition, the films showed consistently well-defined, dopamine electrochemical redox activity. The Mo/Re substrate regions that were uncoated but still exposed to the diamond-growth environment remained substantially more flexible than tungsten in a bend-to-fracture rotation test, bending to the test maximum of 90° and not fracturing. The W/Re substrates fractured after a 27° bend, and the tungsten fractured after a 21° bend. Brittle, transgranular cleavage fracture surfaces were observed for tungsten and W/Re. A tension-induced fracture of the Mo/Re after the prior bend test showed a dimple fracture with a visible ductile core. Overall, the Mo/Re and W/Re alloys were suitable substrates for diamond growth. The Mo/Re alloy remained significantly more ductile than traditional tungsten substrates after diamond growth, and thus may be an attractive metal substrate for more ductile, thin-film diamond electrodes.

  1. Synthesis and characterization of carbon or/and boron-doped CdS nanoparticles and investigation of optical and photoluminescence properties

    International Nuclear Information System (INIS)

    Fakhri, Ali; Khakpour, Reza

    2015-01-01

    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

  2. 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.

  3. Effect of reaction conditions on methyl red degradation mediated by boron and nitrogen doped TiO2

    International Nuclear Information System (INIS)

    Galenda, A.; Crociani, L.; Habra, N. El; Favaro, M.; Natile, M.M.; Rossetto, G.

    2014-01-01

    Highlights: • Boron and/or nitrogen-doped TiO 2 for photocatalytic wastewater treatment. • Methyl red degradation/mineralisation as a function of pH, acids and dopants. • Adsorption time influence on photocatalytic process. • Recovery of worn-out catalyst. - Abstract: Nowadays the employment of renewable and sustainable energy sources, and solar light as main option, becomes an urgent need. Photocatalytic processes received great attention in wastewater treatment due to their cheapness, environmental compatibility and optimal performances. Despite the general low selectivity of the photocatalysts, an accurate optimisation of the operational parameters needs to be carried out in order to maximise the process yield. Because of this reason, the present contribution aims to deepen either the knowledge in boron and/or nitrogen doped TiO 2 -based systems and their employment in methyl red removal from aqueous solutions. The samples were obtained by coprecipitation and characterised by XRD, SEM, BET specific surface area, UV–vis and XPS techniques. The catalytic activity was for the first time carefully evaluated with respect to methyl red photodegradation in different conditions as a function of working pH, counter-ions and pre-adsorption time. An ad-hoc study was performed on the importance of the pre-adsorption of the dye, suggesting that an extended adsorption is useless for the catalyst photoactivity, while a partial coverage is preferable. The photocatalytic tests demonstrate the positive influence of boron doping in photo-activated reactions and the great importance of the operational parameters with respect to the simple methyl red bleaching rather than the overall pollutant mineralisation. It is proved, indeed, that different working pH, acidifying means and substrate pre-adsorption time can enhance or limit the catalyst performances with respect to the complete pollutant degradation rather than its partial breakage

  4. Effect of Carbon Doping on the Electronic Structure and Elastic Properties of Boron Suboxide

    Science.gov (United States)

    2015-06-01

    bonding complexity . When one equatorial boron atom neighboring a C-B-C chain is replaced by carbon, a Ce-CO bond forms between the equatorial carbon...Scripta Materialia. 2014;76:9. 8. Wang Z, Zhao Y. In situ pressure Raman spectroscopy and mechanical stability of superhard boron suboxide. Appl Phys...Lett. 2005;86:041911. 9. Nifise E. Study of sintering and structure property relationships in boron suboxide – alkaline earth metal oxide, cobalt

  5. Efficient Photocatalytic Hydrogen Evolution over Platinum and Boron Co-doped TiO2 Photoatalysts

    Directory of Open Access Journals (Sweden)

    Zhiliang JIN

    2014-12-01

    Full Text Available In this paper, the new photocatalyst, Ptx-/TiO2-yBy was prepared by impregnation method via coupling with a inorganic water splitting system, namely, a ternary system K+,Na+/B4O72- - H2O for hydrogen evolution. The integration process of the preparation for B doping Pt/TiO2 with the significant photocatalytic hydrogen evolution in the ternary system K+,Mg2+/B4O72- - H2O and K+,Na+/B4O72- - H2O were accomplished by impregnation in situ. The photocatalyst Ptx-/TiO2-yBy synthesis and the photocatalytic hydrogen production of the isothermal solubility of the ternary system K+,Mg2+/B4O72- - H2O and K+,Na+/B4O72- - H2O at 25 ºC have been studied. Thus, the present challenge is not only to demonstrate a suitable photocatalytical system that can efficiently produce hydrogen under the borate exsited, but also research that the addition of borate to the suspensions greatly enhanced the stability of the  photocatalysts over semiconductor catalysts.The results show that borate solution is a suitable for B doped TiO2 photocatalysts preparation and a novel photocatalyst Ptx-/TiO2-yBy was successfully prepared by this way. XRD and XPS characterization showed that both anatase and rutile are coexisted and the B is incorporated into the crystal of the TiO2.So the TiO2 can be denoted as TiO2-xBx. The effect of borate on the photocatalytic properties were investigated. The results showed that the amount of hydrogen evolved is enhanced by factors of 4 with the addition of H3BO3 to the ethanol/water reaction solutions. The role of boron anion does not act as a sacrificial electron donors. DOI: http://dx.doi.org/10.5755/j01.ms.20.4.6412

  6. Diamond nanoparticles as a support for Pt and PtRu catalysts for direct methanol fuel cells.

    Science.gov (United States)

    La-Torre-Riveros, Lyda; Guzman-Blas, Rolando; Méndez-Torres, Adrián E; Prelas, Mark; Tryk, Donald A; Cabrera, Carlos R

    2012-02-01

    Diamond in nanoparticle form is a promising material that can be used as a robust and chemically stable catalyst support in fuel cells. It has been studied and characterized physically and electrochemically, in its thin film and powder forms, as reported in the literature. In the present work, the electrochemical properties of undoped and boron-doped diamond nanoparticle electrodes, fabricated using the ink-paste method, were investigated. Methanol oxidation experiments were carried out in both half-cell and full fuel cell modes. Platinum and ruthenium nanoparticles were chemically deposited on undoped and boron doped diamond nanoparticles through the use of NaBH(4) as reducing agent and sodium dodecyl benzene sulfonate (SDBS) as a surfactant. Before and after the reduction process, samples were characterized by electron microscopy and spectroscopic techniques. The ink-paste method was also used to prepare the membrane electrode assembly with Pt and Pt-Ru modified undoped and boron-doped diamond nanoparticle catalytic systems, to perform the electrochemical experiments in a direct methanol fuel cell system. The results obtained demonstrate that diamond supported catalyst nanomaterials are promising for methanol fuel cells.

  7. Fabrication and characterization of physically defined quantum dots on a boron-doped silicon-on-insulator substrate

    Science.gov (United States)

    Mizoguchi, Seiya; Shimatani, Naoki; Kobayashi, Mizuki; Makino, Takaomi; Yamaoka, Yu; Kodera, Tetsuo

    2018-04-01

    We study hole transport properties in physically defined p-type silicon quantum dots (QDs) on a heavily doped silicon-on-insulator (SOI) substrate. We observe Coulomb diamonds using single QDs and estimate the charging energy as ∼1.6 meV. We obtain the charge stability diagram of double QDs using single QDs as a charge sensor. This is the first demonstration of charge sensing in p-type heavily doped silicon QDs. For future time-resolved measurements, we apply radio-frequency reflectometry using impedance matching of LC circuits to the device. We observe the resonance and estimate the capacitance as ∼0.12 pF from the resonant frequency. This value is smaller than that of the devices with top gates on nondoped SOI substrate. This indicates that high-frequency signals can be applied efficiently to p-type silicon QDs without top gates.

  8. Investigation on the application of boron-, phosphorus and arsenic-doped glasses in the technology of photovoltaic structures

    International Nuclear Information System (INIS)

    Wrobel, E.; Waczynski, K.; Filipowski, W.

    2004-01-01

    The paper presents the investigation studies on the application of spin-on glasses doping technology of mono- and multicrystalline silicon. The objective of the carried out investigation studies was to assess the applicability of the above solutions, containing atoms of boron, phosphorus and arsenic, for the production of the emitter layer of photovoltaic structure. The preparation of these solutions was elaborated and the conditions of thermal treatment of the deposited films were determined, as well as diffusion parameters of the dopant from glass to silicon. The measurements sheet resistance and the profile of dopant concentration of the obtained films were carried out. The carried out diffusion process confirmed the applicability of the worked out emulsion sources dor silicon doping on the required level. (author)

  9. Boron- and nitrogen-doped graphene quantum dots/graphene hybrid nanoplatelets as efficient electrocatalysts for oxygen reduction.

    Science.gov (United States)

    Fei, Huilong; Ye, Ruquan; Ye, Gonglan; Gong, Yongji; Peng, Zhiwei; Fan, Xiujun; Samuel, Errol L G; Ajayan, Pulickel M; Tour, James M

    2014-10-28

    The scarcity and high cost of platinum-based electrocatalysts for the oxygen reduction reaction (ORR) has limited the commercial and scalable use of fuel cells. Heteroatom-doped nanocarbon materials have been demonstrated to be efficient alternative catalysts for ORR. Here, graphene quantum dots, synthesized from inexpensive and earth-abundant anthracite coal, were self-assembled on graphene by hydrothermal treatment to form hybrid nanoplatelets that were then codoped with nitrogen and boron by high-temperature annealing. This hybrid material combined the advantages of both components, such as abundant edges and doping sites, high electrical conductivity, and high surface area, which makes the resulting materials excellent oxygen reduction electrocatalysts with activity even higher than that of commercial Pt/C in alkaline media.

  10. Investigation of electrically-active deep levels in single-crystalline diamond by particle-induced charge transient spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kada, W., E-mail: kada.wataru@gunma-u.ac.jp [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Kambayashi, Y.; Ando, Y. [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Onoda, S. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Umezawa, H.; Mokuno, Y. [National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan); Shikata, S. [Kwansei Gakuin Univ., 2-1, Gakuen, Mita, Hyogo 669-1337 (Japan); Makino, T.; Koka, M. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Hanaizumi, O. [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Kamiya, T.; Ohshima, T. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan)

    2016-04-01

    To investigate electrically-active deep levels in high-resistivity single-crystalline diamond, particle-induced charge transient spectroscopy (QTS) techniques were performed using 5.5 MeV alpha particles and 9 MeV carbon focused microprobes. For unintentionally-doped (UID) chemical vapor deposition (CVD) diamond, deep levels with activation energies of 0.35 eV and 0.43 eV were detected which correspond to the activation energy of boron acceptors in diamond. The results suggested that alpha particle and heavy ion induced QTS techniques are the promising candidate for in-situ investigation of deep levels in high-resistivity semiconductors.

  11. Further improvement of mechanical and tribological properties of Cr-doped diamond-like carbon nanocomposite coatings by N codoping

    Science.gov (United States)

    Zou, Changwei; Xie, Wei; Tang, Xiaoshan

    2016-11-01

    In this study, the effects of nitrogen codoping on the microstructure and mechanical properties of Cr-doped diamond-like carbon (DLC) nanocomposite coatings were investigated in detail. Compared with undoped DLC coatings, the Cr-DLC and N/Cr-DLC coatings showed higher root-mean-square (RMS) roughness values. However, from the X-ray photoelectron spectroscopy (XPS) and Raman results, the fraction of sp2 carbon bonds of N/Cr-DLC coatings increased with increasing N content, which indicated the graphitization of the coatings. The hardness and elastic modulus of N/Cr-DLC coatings with 1.8 at. % N were about 26.8 and 218 GPa, respectively. The observed hardness increase with N codoping was attributed to the incorporation of N in the C network along with the formation of CrC(N) nanoparticles, as confirmed from the transmission electron microscopy (TEM) results. The internal stress markedly decreased from 0.93 to 0.32 GPa as the N content increased from 0 to 10.3 at. %. Furthermore, N doping significantly improved the high-temperature dry friction behavior of DLC coatings. The friction coefficient of N/Cr-DLC coatings with 8.0 and 10.3 at. % N was kept at about 0.2 during the overall sliding test at 500 °C. These results showed that appropriate N doping could promote the mechanical and tribological properties of Cr-DLC nanocomposite coatings.

  12. Study of Nitrogen Effect on the Boron Diffusion during Heat Treatment in Polycrystalline Silicon/Nitrogen-Doped Silicon Thin Films

    Science.gov (United States)

    Saci, Lynda; Mahamdi, Ramdane; Mansour, Farida; Boucher, Jonathan; Collet, Maéva; Bedel Pereira, Eléna; Temple-Boyer, Pierre

    2011-05-01

    The present paper studies the boron (B) diffusion in nitrogen (N) doped amorphous silicon (a-Si) layer in original bi-layer B-doped polycrystalline silicon (poly-Si)/in-situ N-doped Si layers (NIDOS) thin films deposited by low pressure chemical vapor deposition (LPCVD) technique. The B diffusion in the NIDOS layer was investigated by secondary ion mass spectrometry (SIMS) and Fourier transform infrared spectroscopy (FTIR) analysis. A new extended diffusion model is proposed to fit the SIMS profile of the bi-layer films. This model introduces new terms which take into account the effect of N concentration on the complex diffusion phenomena of B atoms in bi-layer films. SIMS results show that B diffusion does not exceed one third of NIDOS layer thickness after annealing. The reduction of the B diffusion in the NIDOS layer is due to the formation of complex B-N as shown by infrared absorption measurements. Electrical measurements using four-probe and Hall effect techniques show the good conductivity of the B-doped poly-Si layer after annealing treatment.

  13. Boron-Proton Nuclear-Fusion Enhancement Induced in Boron-Doped Silicon Targets by Low-Contrast Pulsed Laser

    Directory of Open Access Journals (Sweden)

    A. Picciotto

    2014-08-01

    Full Text Available We show that a spatially well-defined layer of boron dopants in a hydrogen-enriched silicon target allows the production of a high yield of alpha particles of around 10^{9} per steradian using a nanosecond, low-contrast laser pulse with a nominal intensity of approximately 3×10^{16}  W cm^{−2}. This result can be ascribed to the nature of the long laser-pulse interaction with the target and with the expanding plasma, as well as to the optimal target geometry and composition. The possibility of an impact on future applications such as nuclear fusion without production of neutron-induced radioactivity and compact ion accelerators is anticipated.

  14. Fabrication and characterization of an all-diamond tubular flow microelectrode for electroanalysis.

    Science.gov (United States)

    Hutton, Laura A; Vidotti, Marcio; Iacobini, James G; Kelly, Chris; Newton, Mark E; Unwin, Patrick R; Macpherson, Julie V

    2011-07-15

    The development of the first all-diamond hydrodynamic flow device for electroanalytical applications is described. Here alternate layers of intrinsic (insulating), conducting (heavily boron doped), and intrinsic polycrystalline diamond are grown to create a sandwich structure. By laser cutting a hole through the material, it is possible to produce a tubular flow ring electrode of a characteristic length defined by the thickness of the conducting layer (for these studies ∼90 μm). The inside of the tube can be polished to 17 ± 10 nm surface roughness using a diamond impregnanted wire resulting in a coplanar, smooth, all-diamond surface. The steady-state limiting current versus volume flow rate characteristics for the one electron oxidation of FcTMA(+) are in agreement with those expected for laminar flow in a tubular electrode geometry. For dopamine detection, it is shown that the combination of the reduced fouling properties of boron doped diamond, coupled with the flow geometry design where the products of electrolysis are washed away downstream of the electrode, completely eradicates fouling during electrolysis. This paves the way for incorporation of this flow design into online electroanalytical detection systems. Finally, the all diamond tubular flow electrode system described here provides a platform for future developments including the development of ultrathin ring electrodes, multiple apertures for increased current response, and multiple, individually addressable ring electrodes incorporated into the same flow tube.

  15. Diamond nanophotonics

    Directory of Open Access Journals (Sweden)

    Katja Beha

    2012-12-01

    Full Text Available We demonstrate the coupling of single color centers in diamond to plasmonic and dielectric photonic structures to realize novel nanophotonic devices. Nanometer spatial control in the creation of single color centers in diamond is achieved by implantation of nitrogen atoms through high-aspect-ratio channels in a mica mask. Enhanced broadband single-photon emission is demonstrated by coupling nitrogen–vacancy centers to plasmonic resonators, such as metallic nanoantennas. Improved photon-collection efficiency and directed emission is demonstrated by solid immersion lenses and micropillar cavities. Thereafter, the coupling of diamond nanocrystals to the guided modes of micropillar resonators is discussed along with experimental results. Finally, we present a gas-phase-doping approach to incorporate color centers based on nickel and tungsten, in situ into diamond using microwave-plasma-enhanced chemical vapor deposition. The fabrication of silicon–vacancy centers in nanodiamonds by microwave-plasma-enhanced chemical vapor deposition is discussed in addition.

  16. Boron and nitrogen doping of graphene via thermal exfoliation of graphite oxide in a BF3 or NH3 atmosphere: contrasting properties

    Czech Academy of Sciences Publication Activity Database

    Poh, H. L.; Šimek, P.; Sofer, Z.; Tomandl, Ivo; Pumera, M.

    2013-01-01

    Roč. 1, č. 42 (2013), s. 13146-13153 ISSN 2050-7488 R&D Projects: GA MŠk(XE) LM2011019 Institutional support: RVO:61389005 Keywords : Boron and nitrogen doping * Prompt gamma-ray activation analysis * Graphene lattices Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders

  17. Diamond field-effect transistors for RF power electronics: Novel NO2 hole doping and low-temperature deposited Al2O3 passivation

    Science.gov (United States)

    Kasu, Makoto

    2017-01-01

    Diamond possesses a combination of exceptional physical properties and is expected to be used as a semiconductor material in high-efficiency and high-power electronic devices. In this study, hole doping was observed when using NO2 molecules on a H-diamond surface. The activation energy of hole concentration in NO2/H-diamond was measured as 0.006 eV, and holes were fully activated at room temperature. A thermal stabilization of the hole channel was realized by passivation with an atomic-layer-deposited Al2O3 layer. The passivation method enabled the realization of a thermally stable high-performance diamond field-effect transistor (FET), which exhibited high-performance DC and RF characteristics. NO2 hole-doping and Al2O3-passivation technologies enabled reproducible measurements of MOS structure electric properties. Such technologies also facilitated observations of two-dimensional holes at the MOS interface and type-II band alignment of Al2O3/NO2/H-diamond. Additionally, the band diagram under various gate bias conditions was proposed on the basis of capacitance-voltage measurements and analysis using Poisson’s equations.

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

    Indian Academy of Sciences (India)

    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 ...

  19. Chromium-doped diamond-like carbon films deposited by dual-pulsed laser deposition

    Czech Academy of Sciences Publication Activity Database

    Písařík, Petr; Jelínek, Miroslav; Kocourek, Tomáš; Zezulová, M.; Remsa, Jan; Jurek, Karel

    2014-01-01

    Roč. 117, č. 1 (2014), s. 83-88 ISSN 0947-8396 R&D Projects: GA MŠk LD12069 Institutional support: RVO:68378271 Keywords : diamond like carbon * chromium * contact angle * surface free energy * dual laser deposition * zeta potential Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.704, year: 2014

  20. Superconductive B-doped nanocrystalline diamond thin films: Electrical transport and Raman spectra

    Czech Academy of Sciences Publication Activity Database

    Nesládek, M.; Tromson, D.; Mer, Ch.; Bergonzo, P.; Hubík, Pavel; Mareš, Jiří J.

    2006-01-01

    Roč. 88, č. 23 (2006), 232111/1-232111/3 ISSN 0003-6951 R&D Projects: GA ČR(CZ) GA202/06/0040 Institutional research plan: CEZ:AV0Z10100521 Keywords : nanocrystalline diamond * superconductivity * magnetoresistance * Raman spectroscopy * Fano resonance Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.977, year: 2006

  1. 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.

  2. The diamond/aqueous electrolyte interface: an impedance investigation.

    Science.gov (United States)

    Garrido, Jose A; Nowy, Stefan; Härtl, Andreas; Stutzmann, Martin

    2008-04-15

    We have investigated the electrochemical interface between diamond electrodes and aqueous electrolytes using electrochemical techniques such as cyclic voltammetry and ac impedance spectroscopy. High-quality CVD-grown boron-doped polycrystalline diamond electrodes and IIa single crystalline natural diamond electrodes have been used in this study. In the case of hydrogen-terminated diamond electrodes, the electrochemical interface is dominated by the electrochemical double layer. Frequency-dependent impedance spectroscopy reveals a potential regime in which the contribution of ion adsorption becomes relevant. We have conducted experiments to evaluate the effect of pH and ionic strength on the double layer. Our results suggest that only ions resulting from water auto-dissociation, i.e., hydroxide and hydronium ions, are responsible for ion adsorption and, thus, able to modify the charge at the double layer. In contrast, no effect of the adsorption of several dissolved ions (such as Na+, K+, Cl-) has been observed On the basis of the electrochemical characterization of H-terminated diamond surfaces, we also discuss the phenomenon of the surface conductivity in diamond, as well as the pH sensitivity of the diamond surface. The influence of the O2/OH- and H2/H3O+ redox couples on the origin of the surface conductivity is discussed.

  3. Amorphous boron-doped sodium titanates hydrates: Efficient and reusable adsorbents for the removal of Pb2+from water.

    Science.gov (United States)

    di Bitonto, Luigi; Volpe, Angela; Pagano, Michele; Bagnuolo, Giuseppe; Mascolo, Giuseppe; La Parola, Valeria; Di Leo, Paola; Pastore, Carlo

    2017-02-15

    Amorphous titanium hydroxide and boron-doped (B-doped) sodium titanates hydrates were synthetized and used as adsorbents for the removal of Pb 2+ from water. The use of sodium borohydride (NaBH 4 ) and titanium(IV) isopropoxide (TTIP) as precursors permits a very easy synthesis of B-doped adsorbents at 298K. The new adsorbent materials were first chemically characterized (XRD, XPS, SEM, DRIFT and elemental analysis) and then tested in Pb 2+ adsorption batch experiments, in order to define kinetics and equilibrium studies. The nature of interaction between such sorbent materials and Pb 2+ was also well defined: besides a pure adsorption due to hydroxyl interaction functionalities, there is also an ionic exchange between Pb 2+ and sodium ions even working at pH 4.4. Langmuir model presented the best fitting with a maximum adsorption capacity up to 385mg/g. The effect of solution pH and common ions (i.e. Na + , Ca 2+ and Mg 2+ ) onto Pb 2+ sorption were also investigated. Finally, recovery was positively conducted using EDTA. Very efficient adsorption (>99.9%) was verified even using tap water spiked with traces of Pb 2+ (50ppb). Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Ga-doped and antisite double defects enhance the sensitivity of boron nitride nanotubes towards Soman and Chlorosoman

    International Nuclear Information System (INIS)

    Javan, Masoud Bezi; Soltani, Alireza; Ghasemi, A.S.; Lemeski, E.Tazikeh; Gholami, Niloofar; Balakheyli, Hanzaleh

    2017-01-01

    Highlights: • Adsorptions of soman and chlorosoman over the BN nanotubes were investigated. • Adsorption energy of soman and chlorosoman on BGaNNT nanotube is more stable than B-BNNT. • BGaNNT can used to remove the toxic agents containing soman and chlorosoman molecules. • B-BNNT can detect the toxic agents containing soman and chlorosoman molecules. - Abstract: Adsorption of Soman and Chlorosoman over the outer surface of boron nitride nanotube (BNNT) was studied using density functional theory (DFT) calculations to consider its sensitivity toward mentioned nerve agents. Then, we studied the sensitivity of Ga-doped BNNT and double-antisite defective BNNT (d-BNNT) effects towards adsorbed molecule resulting in eye-catching sensitivity of defected adsorbents representing strong chemical adsorption on the Ga-doped BNNT, while they are mainly physisorbed on the pure BNNT with negligible electronic properties. Density of states (DOSs) was analyzed for further understanding of electronic properties of the applied configurations. Charges were moved from BNNT to the single molecules while in case of Ga-doped and d-BNNT; the charges were transferred from single molecules to the defected adsorbents. These along with outcomes of quantum molecular descriptors, difference in energy gap (E g ), and dipole moments clearly reveal that the d-BNNT is a promising sensor material for the detection of these nerve agents.

  5. Ga-doped and antisite double defects enhance the sensitivity of boron nitride nanotubes towards Soman and Chlorosoman

    Energy Technology Data Exchange (ETDEWEB)

    Javan, Masoud Bezi [Physics Department, Faculty of Sciences, Golestan University, Gorgan (Iran, Islamic Republic of); Soltani, Alireza, E-mail: Alireza.soltani46@yahoo.com [Golestan Rheumatology Research Center, Golestan University of Medical Science, Gorgan (Iran, Islamic Republic of); Young Researchers and Elite Club, Gorgan Branch, Islamic Azad University, Gorgan (Iran, Islamic Republic of); Ghasemi, A.S. [Department Chemistry, Payame Noor University, P.O. Box, 19395-3697, Tehran (Iran, Islamic Republic of); Lemeski, E.Tazikeh [Department of Chemistry, Gorgan Branch, Islamic Azad University, Gorgan (Iran, Islamic Republic of); Gholami, Niloofar [Young Researchers and Elite Club, Gorgan Branch, Islamic Azad University, Gorgan (Iran, Islamic Republic of); Balakheyli, Hanzaleh [Golestan Rheumatology Research Center, Golestan University of Medical Science, Gorgan (Iran, Islamic Republic of)

    2017-07-31

    Highlights: • Adsorptions of soman and chlorosoman over the BN nanotubes were investigated. • Adsorption energy of soman and chlorosoman on BGaNNT nanotube is more stable than B-BNNT. • BGaNNT can used to remove the toxic agents containing soman and chlorosoman molecules. • B-BNNT can detect the toxic agents containing soman and chlorosoman molecules. - Abstract: Adsorption of Soman and Chlorosoman over the outer surface of boron nitride nanotube (BNNT) was studied using density functional theory (DFT) calculations to consider its sensitivity toward mentioned nerve agents. Then, we studied the sensitivity of Ga-doped BNNT and double-antisite defective BNNT (d-BNNT) effects towards adsorbed molecule resulting in eye-catching sensitivity of defected adsorbents representing strong chemical adsorption on the Ga-doped BNNT, while they are mainly physisorbed on the pure BNNT with negligible electronic properties. Density of states (DOSs) was analyzed for further understanding of electronic properties of the applied configurations. Charges were moved from BNNT to the single molecules while in case of Ga-doped and d-BNNT; the charges were transferred from single molecules to the defected adsorbents. These along with outcomes of quantum molecular descriptors, difference in energy gap (E{sub g}), and dipole moments clearly reveal that the d-BNNT is a promising sensor material for the detection of these nerve agents.

  6. [Influence of deposition time on chromatics during nitrogen-doped diamond like carbon coating on pure titanium].

    Science.gov (United States)

    Yin, Lu; Yao, Jiang-wu; Xu, De-wen

    2010-10-01

    The aim of this study was to observed the influence of deposition time on chromatics during nitrogen-doped diamond like carbon coating (N-DLC) on pure titanium by multi impulse are plasma plating machine. Applying multi impulse are plasma plating machine to produce TiN coatings on pure titanium in nitrogen atmosphere, then filming with nitrogen-doped DLC on TiN in methane (10-80 min in every 5 min). The colors of N-DLC were evaluated in the CIE1976 L*a*b* uniform color scale and Mussell notation. The surface morphology of every specimen was analyzed using scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). When changing the time of N-DLC coating deposition, N-DLC surface showed different color. Golden yellow was presented when deposition time was 30 min. SEM showed that crystallization was found in N-DLC coatings, the structure changed from stable to clutter by varying the deposition time. The chromatics of N-DLC coatings on pure titanium could get golden yellow when deposition time was 30 min, then the crystallized structure was stable.

  7. Gel-hydrothermal synthesis of carbon and boron co-doped TiO{sub 2} and evaluating its photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Wu Yongmei; Xing Mingyang [Key Lab for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China); Zhang Jinlong, E-mail: jlzhang@ecust.edu.cn [Key Lab for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China)

    2011-08-15

    Graphical abstract: Carbon and boron co-doped TiO{sub 2} photocatalysts were prepared firstly by the gel-hydrothermal method, which presented excellent visible light photocatalytic activities, resulting from the coke carbon photosensitization and B-N synergistic effect. Display Omitted Highlights: {yields} Carbon and boron co-doped TiO{sub 2} photocatalysts with larger surface area were prepared firstly by the gel-hydrothermal method. {yields} Surface coke carbon photosensitization effect is responsible for its high photocatalytic activity in the visible light irradiation. {yields} B-C synergistic effects play the major role in its effective photo-degradation of 2,4-DCP under the visible light. - Abstract: Carbon and boron co-doped TiO{sub 2} photocatalysts were prepared firstly by the gel-hydrothermal method, that is, synthesized through sol-gel process followed by hydrothermal in the glucose solution. The prepared photocatalysts were characterized by XRD, Raman spectra, TEM, N{sub 2} physical adsorption, XPS, and UV-vis absorption spectra. It was found that the co-doped TiO{sub 2} has a larger BET surface areas and a narrower band gap than undoped TiO{sub 2}. The experimental results show that the coke carbon generated on the carbon doped TiO{sub 2} surface act as a photosensitizer and has the photosensitization effect under the visible light. Except for carbon sensitization effect, the boron and carbon co-doped TiO{sub 2} has synergistic effect which is responsible for effective photo-degradation of 2,4-dichlorophenol in the visible light irradiation.

  8. 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 EU Projects: European Commission(XE) 238201 - MATCON Institutional support: RVO:68378271 Keywords : boron-doped diamond * solar cell * heterostructure * water splitting Subject RIV: JI - Composite Materials Impact factor: 1.616, year: 2014

  9. Spectrally dependent photovoltages in Schottky photodiode based on (100) B-doped diamond

    Czech Academy of Sciences Publication Activity Database

    Čermák, Jan; Koide, Y.; Takeuchi, D.; Rezek, Bohuslav

    2014-01-01

    Roč. 115, č. 5 (2014), "053105-1"-"053105-6" ISSN 0021-8979 R&D Projects: GA ČR(CZ) GBP108/12/G108 Grant - others:AVČR(CZ) M100101209 Institutional support: RVO:68378271 Keywords : Schottky barrier * diamond * Kelvin probe force microscopy * surface photovoltage Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.183, year: 2014

  10. n-Type phosphorus-doped nanocrystalline diamond: electrochemical and in situ Raman spectroelectrochemical study

    Czech Academy of Sciences Publication Activity Database

    Vlčková Živcová, Zuzana; Frank, Otakar; Drijkoningen, S.; Haenen, K.; Mortet, Vincent; Kavan, Ladislav

    2016-01-01

    Roč. 6, č. 56 (2016), s. 51387-51393 ISSN 2046-2069 R&D Projects: GA ČR GA13-31783S Grant - others:AV ČR(CZ) G.0456.1 Institutional support: RVO:61388955 ; RVO:68378271 Keywords : Amorphous films * Cyclic voltammetry * Diamond films Subject RIV: CG - Electrochemistry; BM - Solid Matter Physics ; Magnetism (FZU-D) Impact factor: 3.108, year: 2016

  11. Giant magnetic anisotropy and robust quantum anomalous Hall effect in boron-doped graphene with Re-adsorption

    Science.gov (United States)

    Zhang, Kai-Cheng; Li, Yong-Feng; Liu, Yong; Zhu, Yan

    2018-04-01

    Recently topological materials have attracted much attention due to their quantization transports as well as edge states. It will be excellent to realize the robust quantum anomalous Hall transports in graphene-based devices. Using density-functional theory and tight-binding method, we investigated the structural, magnetic and topological properties for the boron-doped graphene with Re-adsorption. A large band-gap of 32.5 meV is opened by the Rashba spin-orbital coupling, and the band-gap is robust against the shape deformation of  ± 4% along the zigzag direction. Giant magnetic anisotropy emerges in this adsorption system together with the Fermi level lying in the band gap. Both the magnetic anisotropy and the band gap can be tuned by a moderate electric field. Calculations reveal that the system exhibits the quantization transports with the Chern number C=2 .

  12. Conductive Boron-Doped Graphene as an Ideal Material for Electrocatalytically Switchable and High-Capacity Hydrogen Storage.

    Science.gov (United States)

    Tan, Xin; Tahini, Hassan A; Smith, Sean C

    2016-12-07

    Electrocatalytic, switchable hydrogen storage promises both tunable kinetics and facile reversibility without the need for specific catalysts. The feasibility of this approach relies on having materials that are easy to synthesize, possessing good electrical conductivities. Graphitic carbon nitride (g-C 4 N 3 ) has been predicted to display charge-responsive binding with molecular hydrogen-the only such conductive sorbent material that has been discovered to date. As yet, however, this conductive variant of graphitic carbon nitride is not readily synthesized by scalable methods. Here, we examine the possibility of conductive and easily synthesized boron-doped graphene nanosheets (B-doped graphene) as sorbent materials for practical applications of electrocatalytically switchable hydrogen storage. Using first-principle calculations, we find that the adsorption energy of H 2 molecules on B-doped graphene can be dramatically enhanced by removing electrons from and thereby positively charging the adsorbent. Thus, by controlling charge injected or depleted from the adsorbent, one can effectively tune the storage/release processes which occur spontaneously without any energy barriers. At full hydrogen coverage, the positively charged BC 5 achieves high storage capacities up to 5.3 wt %. Importantly, B-doped graphene, such as BC 49 , BC 7 , and BC 5 , have good electrical conductivity and can be easily synthesized by scalable methods, which positions this class of material as a very good candidate for charge injection/release. These predictions pave the route for practical implementation of electrocatalytic systems with switchable storage/release capacities that offer high capacity for hydrogen storage.

  13. Enriched Boron-Doped Amorphous Selenium Based Position-Sensitive Solid-State Thermal Neutron Detector for MPACT Applications

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Krishna [Univ. of South Carolina, Columbia, SC (United States)

    2017-09-29

    High-efficiency thermal neutron detectors with compact size, low power-rating and high spatial, temporal and energy resolution are essential to execute non-proliferation and safeguard protocols. The demands of such detector are not fully covered by the current detection system such as gas proportional counters or scintillator-photomultiplier tube combinations, which are limited by their detection efficiency, stability of response, speed of operation, and physical size. Furthermore, world-wide shortage of 3He gas, required for widely used gas detection method, has further prompted to design an alternative system. Therefore, a solid-state neutron detection system without the requirement of 3He will be very desirable. To address the above technology gap, we had proposed to develop new room temperature solidstate thermal neutron detectors based on enriched boron (10B) and enriched lithium (6Li) doped amorphous Se (As- 0.52%, Cl 5 ppm) semiconductor for MPACT applications. The proposed alloy materials have been identified for its many favorable characteristics - a wide bandgap (~2.2 eV at 300 K) for room temperature operation, high glass transition temperature (tg ~ 85°C), a high thermal neutron cross-section (for boron ~ 3840 barns, for lithium ~ 940 barns, 1 barn = 10-24 cm2), low effective atomic number of Se for small gamma ray sensitivity, and high radiation tolerance due to its amorphous structure.

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

    Science.gov (United States)

    Hees, J; Heidrich, N; Pletschen, W; Sah, R E; Wolfer, M; Williams, O A; Lebedev, V; Nebel, C E; Ambacher, O

    2013-01-18

    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 (10(8) cm(-2)), in the case of hydrogen-treated ND seeding particles, to very high values of 10(11) 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.

  15. Sintering of nano crystalline α silicon carbide by doping with boron ...

    Indian Academy of Sciences (India)

    Sinterable nano silicon carbide powders of mean particle size (37 nm) were prepared by attrition milling and chemical processing of an acheson type alpha silicon carbide having mean particle size of 0.39 m (390 nm). Pressureless sintering of these powders was achieved by addition of boron carbide of 0.5 wt% together ...

  16. Sintering of nano crystalline α silicon carbide by doping with boron ...

    Indian Academy of Sciences (India)

    Unknown

    the use of sintering aids. In the meantime, Prochazka. (1975) reported that with addition of boron and carbon to submicron size β-SiC, sintering of silicon carbide to near theoretical density was achieved. He proposed that during the firing of pure submicron powders of covalently bonded solids, densification is prevented by a ...

  17. Work Function Characterization of Potassium-Intercalated, Boron Nitride Doped Graphitic Petals

    Directory of Open Access Journals (Sweden)

    Patrick T. McCarthy

    2017-07-01

    Full Text Available This paper reports on characterization techniques for electron emission from potassium-intercalated boron nitride-modified graphitic petals (GPs. Carbon-based materials offer potentially good performance in electron emission applications owing to high thermal stability and a wide range of nanostructures that increase emission current via field enhancement. Furthermore, potassium adsorption and intercalation of carbon-based nanoscale emitters decreases work functions from approximately 4.6 eV to as low as 2.0 eV. In this study, boron nitride modifications of GPs were performed. Hexagonal boron nitride is a planar structure akin to graphene and has demonstrated useful chemical and electrical properties when embedded in graphitic layers. Photoemission induced by simulated solar excitation was employed to characterize the emitter electron energy distributions, and changes in the electron emission characteristics with respect to temperature identified annealing temperature limits. After several heating cycles, a single stable emission peak with work function of 2.8 eV was present for the intercalated GP sample up to 1,000 K. Up to 600 K, the potassium-intercalated boron nitride modified sample exhibited improved retention of potassium in the form of multiple emission peaks (1.8, 2.5, and 3.3 eV resulting in a large net electron emission relative to the unmodified graphitic sample. However, upon further heating to 1,000 K, the unmodified GP sample demonstrated better stability and higher emission current than the boron nitride modified sample. Both samples deintercalated above 1,000 K.

  18. Fullerenes as alternative acceptors by transfer doping of diamond surfaces; Fullerene als alternative Akzeptoren bei der Transferdotierung von Diamantoberflaechen

    Energy Technology Data Exchange (ETDEWEB)

    Strobel, Paul

    2008-06-06

    The topic of this thesis is the fullerene induced surface conductivity on hydrogen terminated diamond. A systematic investigation of C{sub 60}, C{sub 60}F{sub 18}, C{sub 60}F{sub 36} and C{sub 60}F{sub 48} as transfer dopants on hydrogenated diamond has been performed. For C{sub 60}, the doping mechanism is more accurately described as a charge exchange in an extreme type II heterojunction. On the other hand a molecular surface acceptor model that takes the degeneracy of holes and the electric field caused by charge separation into account has been performed for the case of C{sub 60}F{sub 48} in excellent agreement with experimental results. Using in situ Hall Effect measurements of air, C{sub 60}, and C{sub 60}F{sub 48} induced conductivity the sign of the charge carriers that dominate the transport properties was determined. At ambient temperature the hole mobility {mu} as a function of the induced charge carrier density p between p=5.10{sup 10} cm{sup -2} and p=3.10{sup 13} cm{sup -2} was measured. A maximum of the mobility of 130-150 cm{sup 2}V{sup -1}s{sup -1} occurs for p=2.10{sup 1} cm{sup -2}. Temperature dependent Hall measurements between 77 and 350 K show a non-activated, constant charge carrier density on all examinated samples, independently of the kind of adsorbates. On the other hand, both the conductivity and the mobility exhibit temperature dependence, varying with the charge carrier concentration. An essential part of this thesis addressed the investigation and the improvement of the thermal stability of the fullerene layers. In order to achieve the covalent attachment of C{sub 60}F{sub 48} to a hydrogen terminated diamond surface a process for controlled partially hydrolisation was developed. Functionalization with hydroxyl groups could be achieved by using a remote water vapour plasma at room temperature for a few seconds as demonstrated by photoelectron spectroscopy. Prolonged water plasma exposure, however, as well as annealing at temperatures

  19. Photo-Hall measurements on phosphorus-doped n-type CVD diamond at low temperatures

    Czech Academy of Sciences Publication Activity Database

    Remeš, Zdeněk; Kalish, R.; Uzan-Saguy, C.; Baskin, E.; Nesládek, M.; Koizumi, S.

    2003-01-01

    Roč. 199, č. 1 (2003), s. 82-86 ISSN 0031-8965 EU Projects: European Commission(XE) HPRN-CT-1999-00139 Institutional research plan: CEZ:AV0Z1010914 Keywords : photo-Hall measurements * CVD diamonnd * phosphorus doped Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.950, year: 2003

  20. Thermal spin filtering effect and giant magnetoresistance of half-metallic graphene nanoribbon co-doped with non-metallic Nitrogen and Boron

    Science.gov (United States)

    Huang, Hai; Zheng, Anmin; Gao, Guoying; Yao, Kailun

    2018-03-01

    Ab initio calculations based on density functional theory and non-equilibrium Green's function are performed to investigate the thermal spin transport properties of single-hydrogen-saturated zigzag graphene nanoribbon co-doped with non-metallic Nitrogen and Boron in parallel and anti-parallel spin configurations. The results show that the doped graphene nanoribbon is a full half-metal. The two-probe system based on the doped graphene nanoribbon exhibits various excellent spin transport properties, including the spin-filtering effect, the spin Seebeck effect, the single-spin negative differential thermal resistance effect and the sign-reversible giant magnetoresistance feature. Excellently, the spin-filtering efficiency can reach nearly 100% in the parallel configuration and the magnetoresistance ratio can be up to -1.5 × 1010% by modulating the electrode temperature and temperature gradient. Our findings indicate that the metal-free doped graphene nanoribbon would be a promising candidate for spin caloritronic applications.

  1. Thermodynamical and thermoelectric properties of boron doped YPd{sub 3} and YRh{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Dwivedi, Shalini; Sharma, Yamini, E-mail: sharma.yamini62@gmail.com [Theoretical Condensed Matter Physics Laboratory, Dept. of Physics, Feroze Gandhi College, Raebareli-229001 U.P (India); Sharma, Ramesh [Dept. of Physics, Mewar University, Chittorgarh-312901 Rajasthan (India)

    2016-05-23

    The structural, electronic, thermal, and optical properties of borides of cubic non-magnetic YX{sub 3} (X=Rh, Pd) compounds and their borides which crystallize in the AuCu{sub 3} structure have been studied using the density functional theory (DFT). The flat bands in the vicinity of E{sub F} which are associated with superconductivity appear in YPd{sub 3} and YRh{sub 3} band structures. However, the B s-states enhance the flat band only in YRh{sub 3}B. The optical properties clearly show that boron insertion modifies the absorption and transmittance. The YX{sub 3} alloys and their borides exhibit valuable changes in the thermopower and ZT. It is observed that the properties of the Y-X intermetallics change significantly for the Y-Rh and Y-Pd alloys and the presence of single boron atom modifies the properties to a great extent.

  2. Rod-like polyaniline supported on three-dimensional boron and nitrogen-co-doped graphene frameworks for high-performance supercapacitors

    Science.gov (United States)

    Liao, Kexuan; Gao, Jialu; Fan, Jinchen; Mo, Yao; Xu, Qunjie; Min, Yulin

    2017-12-01

    In this work, novel three-dimensional (3D) boron and nitrogen-co-doped three-dimensional (3D) graphene frameworks (BN-GFs) supporting rod-like polyaniline (PANI) are facilely prepared and used as electrodes for high-performance supercapacitors. The results demonstrated that BN-GFs with tuned electronic structure can not only provide a large surface area for rod-like PANI to anchor but also effectively facilitate the ion transfer and charge storage in the electrode. The PANI/BN-GF composite with wrinkled boron and nitrogen-co-doped graphene sheets interconnected by rod-like PANI exhibits excellent capacitive properties with a maximum specific capacitance of 596 F/g at a current density of 0.5 A/g. Notably, they also show excellent cycling stability with more than 81% capacitance retention after 5000 charge-discharge cycles.

  3. Sintering of nano crystalline α silicon carbide by doping with boron ...

    Indian Academy of Sciences (India)

    Unknown

    2.2 Sintering additives. Boron carbide from M/s Starck A, West Germany having a purity of 99⋅5% was used as sintering aid along with carbon. Phenolic resin from M/s Allied Resin & Che- micals Ltd, India, was used as a source for carbon. Phe- nolic resin pyrolizes at high temperature with a carbon yield of 47% (Carbon ...

  4. Electron paramagnetic resonance investigations of carbon-doped β rhombohedral boron

    International Nuclear Information System (INIS)

    Gercke, U.; Siems, C.-D.

    1979-01-01

    Electron paramagnetic resonance (EPR) measurements at 9 and 35 GHz on polycrystalline β rhombohedral boron with various carbon contents resulted in partly resolved absorption spectra. At 300 K the spin density ratio of two lines (called D and E) showed a linear increase with the carbon content. This ratio is temperature dependent. The lines D and E are photo-EPR active with different quantum efficiencies at various temperatures. (Auth.)

  5. Linear and nonlinear absorption properties of diamond-like carbon doped with cu nanoparticles

    DEFF Research Database (Denmark)

    Tamulevičius, Sigitas; Peckus, Domantas; Tamulevičius, Tomas

    2017-01-01

    Ultrafast relaxation processes in diamond-like carbon (DLC) thin films with embedded Cu nanoparticles (DLC:Cu nanocomposites) were investigated by means of transient absorption spectroscopy focusing on localized surface plasmon resonance (LSPR) of photoexcited Cu nanoparticles. Absorption spectra...... of the composite films correspond to the sum of absorption spectra of DLC matrix and Cu nanoparticles; however, Cu nanoparticles strongly dominate in the transient differential absorption. Excitations of DLC matrix and of Cu nanoparticles relax independently revealing no strong interaction. High sensitivity...... measurements enabled to obtain the hot electron relaxation dynamics in Cu nanoparticles in the low excitation intensity conditions. The relaxation time was found to be independent of the excitation intensity up to tens of microjoule per square centimeter per pulse and to increase at higher intensities...

  6. Synthesis, Characterization, and Tribological Evaluation of TiO2-Reinforced Boron and Nitrogen co-Doped Reduced Graphene Oxide Based Hybrid Nanomaterials as Efficient Antiwear Lubricant Additives.

    Science.gov (United States)

    Jaiswal, Vinay; Kalyani; Umrao, Sima; Rastogi, Rashmi B; Kumar, Rajesh; Srivastava, Anchal

    2016-05-11

    The microwave-synthesized reduced graphene oxide (MRG), boron-doped reduced graphene oxide (B-MRG), nitrogen-doped reduced graphene oxide (N-MRG), boron-nitrogen-co-doped reduced graphene oxide (B-N-MRG), and TiO2-reinforced B-N-MRG (TiO2-B-N-MRG) nanomaterials have been synthesized and characterized by various state-of-the-art techniques, like Raman spectroscopy, powder X-ray diffraction, scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. Furthermore, the tribological properties of prepared nanomaterials as antiwear additives in neutral paraffin oil have been evaluated using a four-ball machine at an optimized additive concentration (0.15% w/v). The tribological parameters, like mean wear scar diameter, coefficient of friction, and wear rates, revealed that these nanomaterials have potential to be developed as environmentally friendly sulfated-ash-, phosphorus-, and sulfur-free antiwear lubricant additives. The friction- and wear-reducing behavior of MRG increased upon successive doping of nitrogen, boron, and both nitrogen and boron. Among these additives, B-N-co-doped MRG shows superior tribological behavior in paraffin base oil. Besides this, the load-carrying properties of B-N-co-doped MRG have significantly improved after its reinforcement with TiO2 nanoparticles. A comparative study of the surface morphology of a lubricated track in the presence of various additives has been assessed by SEM and contact-mode atomic force microscopy. The X-ray photoelectron spectroscopy studies have proved that the excellent lubrication properties of TiO2-B-N-MRG are due to the in situ formation of a tribofilm composed of boron nitride, adsorbed graphene layers, and tribosintered TiO2 nanoparticles during the tribocontact. Being sulfur-, halogen-, and phosphorus-free, these graphene-based nanomaterials act as green antiwear additives, protecting interacting

  7. Quantum-confined photoluminescence from size-controlled boron doped nanocrystalline-Si:H/a-SiC{sub x}:H superlattice

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Jun; Ni, Jian, E-mail: elsevier_jianni@163.com; Zhang, JianJun; Liu, Qun; Zhang, XiaoDan; Zhao, Ying

    2014-12-31

    Boron doped nanocrystalline-Si:H/a-SiC{sub x}:H (nc-Si:H/a-SiC{sub x}:H) quantum dot superlattice has been prepared by plasma enhanced chemical vapor deposition at a low temperature of 150 °C. This method for fabricating superlattice allows controlling both the size and density of Si quantum dots in potential well and the characteristics of potential barrier without subsequent annealing treatment. Cross-section high resolution transmission electron microscopy investigations confirm the periodic multi-layer structure of silicon quantum dots (∼ 2 nm diameter) separated by a-SiC{sub x}:H matrix (2–3 nm thickness) with sharp interface. With strong blue photoluminescence and high perpendicular conductivity, boron doped nc-Si:H/a-SiC{sub x}:H quantum dot superlattice shows great advantages in obtaining applicable blue light emission. - Highlights: • Boron-doped nanocrystalline-Si:H/a-SiC{sub x}:H superlattice was fabricated by PECVD. • Sharp well/barrier interface and relatively high density of Si QDs achieved simultaneously. • Room temperature blue photoluminescence is imputable of the quantum confinement effects.

  8. Theoretical Studies of Oxygen Reactivity of Free-Standing and Supported Boron-Doped Graphene.

    Science.gov (United States)

    Di Valentin, Cristiana; Ferrighi, Lara; Fazio, Gianluca

    2016-05-23

    Graphene inertness towards chemical reactivity can be considered as an accepted postulate by the research community. This limit has been recently overcome by chemically and physically modifying graphene through non-metal doping or interfacing with acceptor/donor materials (metals or semiconductors). As a result, outstanding performances as catalytic, electrocatalytic, and photocatalytic material have been observed. In this critical Review we report computational work performed, by our group, on the reactivity of free-standing, metal- and semiconductor-supported B-doped graphene towards oxygen, which is at the basis of extremely important energy-related chemical processes, such as the oxygen reduction reaction. It appears that a combination of doping and interfacing approaches for the activation of graphene can open unconventional and unprecedented reaction paths, thus boosting the potential of modified graphene in many chemical applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Thermodynamical study of boron doped CeX{sub 3} (X=Pd, Rh)

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Ramesh [Dept. of Physics, Mewar University, Chittorgarh Rajasthan-India (India); Dwivedi, Shalini; Sharma, Yamini, E-mail: sharma.yamini62@gmail.com [Theoretical Condensed Matter Physics Laboratory, Dept. of Physics, Feroze Gandhi College, Raebareli-229001 U.P (India)

    2016-05-06

    The structural, electronic, thermal, and optical properties of cubic non magnetic CeX{sub 3}(X=Pd, Rh) compounds which crystallize in the Au{sub 3}Cu structure have been studied using the projected augmented wave (PAW) method within the density functional theory (DFT) with generalized gradient approximation (GGA) for exchange correlation potential. In this paper we have calculated the band structure which are interpreted using the density of states. The optical properties such as extinction coefficients clearly illustrate the changes in CeX{sub 3} due to intercalation of boron. Lattice instability is observed in CePd{sub 3}B from the calculated dynamical properties.

  10. Boron profiles in doped amorphous-silicon solar cells formed by plasma ion deposition

    International Nuclear Information System (INIS)

    Stoddart, C.T.H.; Hunt, C.P.; Coleman, J.H.

    1979-01-01

    Amorphous silicon p-n junction solar cells of large area (100 cm 2 ) and having a quantum efficiency approaching 100% in the blue region have been prepared by plasma ion-plating, the p layer being formed from diborane and silane gases in a cathode glow-discharge. Surface secondary ion mass spectrometry combined with ion beam etching was found to be a very sensitive method with high in-depth resolution for obtaining the initial boron-silicon profile of the solar cell p-n junction. (author)

  11. 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...

  12. Ellipsometric investigation of nitrogen doped diamond thin films grown in microwave CH{sub 4}/H{sub 2}/N{sub 2} plasma enhanced chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Ficek, Mateusz, E-mail: rbogdan@eti.pg.gda.pl [Department of Metrology and Optoelectronics, Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, 11/12 G. Narutowicza St., 80-233 Gdansk (Poland); Institute for Materials Research (IMO), Hasselt University, Wetenschapspark 1, B-3590 Diepenbeek (Belgium); Sankaran, Kamatchi J.; Haenen, Ken [Institute for Materials Research (IMO), Hasselt University, Wetenschapspark 1, B-3590 Diepenbeek (Belgium); IMOMEC, IMEC vzw, Wetenschapspark 1, B-3590 Diepenbeek (Belgium); Ryl, Jacek; Darowicki, Kazimierz [Department of Electrochemistry, Corrosion and Material Engineering, Gdansk University of Technology, 11/12 Narutowicza St., 80-233 Gdansk (Poland); Bogdanowicz, Robert [Department of Metrology and Optoelectronics, Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, 11/12 G. Narutowicza St., 80-233 Gdansk (Poland); Materials and Process Simulation Center, California Institute of Technology, Pasadena, California 91125 (United States); Lin, I-Nan [Department of Physics, Tamkang University, Tamsui 251, Taiwan (China)

    2016-06-13

    The influence of N{sub 2} concentration (1%–8%) in CH{sub 4}/H{sub 2}/N{sub 2} plasma on structure and optical properties of nitrogen doped diamond (NDD) films was investigated. Thickness, roughness, and optical properties of the NDD films in the VIS–NIR range were investigated on the silicon substrates using spectroscopic ellipsometry. The samples exhibited relatively high refractive index (2.6 ± 0.25 at 550 nm) and extinction coefficient (0.05 ± 0.02 at 550 nm) with a transmittance of 60%. The optical investigation was supported by the molecular and atomic data delivered by Raman studies, bright field transmission electron microscopy imaging, and X-ray photoelectron spectroscopy diagnostics. Those results revealed that while the films grown in CH{sub 4}/H{sub 2} plasma contained micron-sized diamond grains, the films grown using CH{sub 4}/H{sub 2}/(4%)N{sub 2} plasma exhibited ultranano-sized diamond grains along with n-diamond and i-carbon clusters, which were surrounded by amorphous carbon grain boundaries.

  13. A Photoemission Electron Microscope Investigation of Chemical Vapor Deposition Diamond Films and Diamond Nucleation

    Science.gov (United States)

    Wang, Congjun

    1993-01-01

    CVD diamond nucleation is investigated using the hot filament technique. The stability of CVD diamond at elevated temperatures in vacuum, O_2, and atomic hydrogen environments are studied using photoemission electron microscopy (PEEM) combined with in-vacuo x-ray photoelectron spectroscopy (XPS). Dissolution, oxidation, and atomic hydrogen etching processes of CVD diamond are observed in real-time. Low field cold electron emission from CVD diamond films has been observed for the first time by PEEM. Nucleation density Mo substrates could be increased from 10^4 to rm 10 ^8/cm^2 by polishing. Heating the substrate to 870^circC in vacuum prior to deposition, or above 1000^ circC at the beginning of deposition, reduced nucleation by more than 100-fold. Reduction in nucleation sites is attributed to annealing. Nucleation on Mo _2C substrates was found to be very poor rm (10^4/cm^2), which shows carbide alone does not promote nucleation. Carbide formation may remove nucleation sites. CVD diamond was found to dissolve into the Mo substrate in vacuum at about 1200^circ C. XPS showed formation of Mo_2 C when the diamond dissolved. Diamond oxidation to gas phase products occurred directly at about 600 ^circC, with no observable participation by the substrate. No detectable etching by atomic hydrogen at a pressure of 1times10^{-4 } torr was observed. Boron doped and "pure" CVD diamond films were found to emit electrons at room temperature under the action of the accelerating electric field of the PEEM (about 30 kV/cm) without photon excitation. The mechanism underlying this phenomenon was investigated with PEEM and by studying the emission current-vs-voltage characteristics of the CVD diamond films. Morphology and crystalline orientation were found to play only a minor role. Impurities in the CVD diamond structure lowers the potential barrier substantially; tunneling of electrons into the vacuum is facile. The effective work function of the emitting CVD diamond films is

  14. Electron and photon degradation in aluminum, gallium and boron doped float zone silicon solar cells

    Science.gov (United States)

    Rahilly, W. P.; Scott-Monck, J.; Anspaugh, B.; Locker, D.

    1976-01-01

    Solar cells fabricated from Al, Ga and B doped Lopex silicon over a range of resistivities were tested under varying conditions of 1 MeV electron fluence, light exposures and thermal cycling. Results indicate that Al and Ga can replace B as a P type dopant to yield improved solar cell performance.

  15. Metal-doped diamond-like carbon films synthesized by filter-arc deposition

    International Nuclear Information System (INIS)

    Weng, K.-W.; Chen, Y.-C.; Lin, T.-N.; Wang, D.-Y.

    2006-01-01

    Diamond-like carbon (DLC) thin films are extensively utilized in the semiconductor, electric and cutting machine industries owing to their high hardness, high elastic modulus, low friction coefficients and high chemical stability. DLC films are prepared by ion beam-assisted deposition (BAD), sputter deposition, plasma-enhanced chemical vapor deposition (PECVD), cathodic arc evaporation (CAE), and filter arc deposition (FAD). The major drawbacks of these methods are the degraded hardness associated with the low sp 3 /sp 2 bonding ratio, the rough surface and poor adhesion caused by the presence of particles. In this study, a self-developed filter arc deposition (FAD) system was employed to prepare metal-containing DLC films with a low particle density. The relationships between the DLC film properties, such as film structure, surface morphology and mechanical behavior, with variation of substrate bias and target current, are examined. Experimental results demonstrate that FAD-DLC films have a lower ratio, suggesting that FAD-DLC films have a greater sp 3 bonding than the CAE-DLC films. FAD-DLC films also exhibit a low friction coefficient of 0.14 and half of the number of surface particles as in the CAE-DLC films. Introducing a CrN interfacial layer between the substrate and the DLC films enables the magnetic field strength of the filter to be controlled to improve the adhesion and effectively eliminate the contaminating particles. Accordingly, the FAD system improves the tribological properties of the DLC films

  16. Compositionally modulated multilayer diamond-like carbon coatings with AlTiSi multi-doping by reactive high power impulse magnetron sputtering

    Science.gov (United States)

    Dai, Wei; Gao, Xiang; Liu, Jingmao; Kwon, Se-Hun; Wang, Qimin

    2017-12-01

    Diamond-like carbon (DLC) coatings with AlTiSi multi-doping were prepared by a reactive high power impulse magnetron sputtering with using a gas mixture of Ar and C2H2 as precursor. The composition, microstructure, compressive stress, and mechanical property of the as-deposited DLC coatings were studied systemically by using SEM, XPS, TEM, Raman spectrum, stress-tester, and nanoindentation as a function of the Ar fraction. The results show that the doping concentrations of the Al, Ti and Si atoms increased as the Ar fraction increased. The doped Ti and Si preferred to bond with C while the doped Al mainly existed in oxidation state without bonding with C. As the doping concentrations increased, TiC carbide nanocrystals were formed in the DLC matrix. The microstructure of coatings changed from an amorphous feature dominant AlTiSi-DLC to a carbide nanocomposite AlTiSi-DLC with TiC nanoparticles embedding. In addition, the coatings exhibited the compositionally modulated multilayer consisting of alternate Al-rich layer and Al-poor layer due to the rotation of the substrate holder and the diffusion behavior of the doped Al which tended to separate from C and diffuse towards the DLC matrix surface owing to its weak interactions with C. The periodic Al-rich layer can effectively release the compressive stress of the coatings. On the other hand, the hard TiC nanoparticles were conducive to the hardness of the coatings. Consequently, the DLC coatings with relatively low residual stress and high hardness could be acquired successfully through AlTiSi multi-doping. It is believed that the AlCrSi multi-doping may be a good way for improving the comprehensive properties of the DLC coatings. In addition, we believe that the DLC coatings with Al-rich multilayered structure have a high oxidation resistance, which allows the DLC coatings application in high temperature environment.

  17. 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.

  18. Photovoltaic devices based on high density boron-doped single-walled carbon nanotube/n-Si heterojunctions

    International Nuclear Information System (INIS)

    Saini, Viney; Li, Zhongrui; Bourdo, Shawn; Kunets, Vasyl P.; Trigwell, Steven; Couraud, Arthur; Rioux, Julien; Boyer, Cyril; Nteziyaremye, Valens; Dervishi, Enkeleda; Biris, Alexandru R.; Salamo, Gregory J.; Viswanathan, Tito; Biris, Alexandru S.

    2011-01-01

    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 B 2 O 3 . 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

  19. Tuning hydrogen storage in lithium-functionalized BC2N sheets by doping with boron and carbon.

    Science.gov (United States)

    Qiu, Nian-xiang; Zhang, Cheng-hua; Xue, Ying

    2014-10-06

    First-principles calculations are used to explore the strong binding of lithium to boron- and carbon-doped BC2N monolayers (BC2NBC and BC2NCN, respectively) without the formation of lithium clusters. In comparison to BC2N and BC2NCB, lithium-decorated BC2NBC and BC2NCN systems possess stronger s-p and p-p hybridization and, hence, the binding energy is higher. Lithium becomes partially positively charged by donating electron density to the more electronegative atoms of the sheet. Attractive van der Waals interactions are responsible for binding hydrogen molecules around the lithium atoms. Each lithium atom can adsorb three hydrogen molecules on both sides of the sheet, with an average hydrogen binding energy of approximately 0.2 eV, which is in the range required for practical applications. The BC2NBC-Li and BC2NCN-Li complexes can serve as high-capacity hydrogen-storage media with gravimetric hydrogen capacities of 9.88 and 9.94 wt %, respectively. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    Science.gov (United States)

    Hébert, Clément; Warnking, Jan; Depaulis, Antoine; Garçon, Laurie Amandine; Mermoux, Michel; Eon, David; Mailley, Pascal; Omnès, Franck

    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. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Spin Current Switching and Spin-Filtering Effects in Mn-Doped Boron Nitride Nanoribbons

    Directory of Open Access Journals (Sweden)

    G. A. Nemnes

    2012-01-01

    Full Text Available The spin transport properties are investigated by means of the first principle approach for boron nitride nanoribbons with one or two substitutional Mn impurities, connected to graphene electrodes. The spin current polarization is evaluated using the nonequilibrium Green’s function formalism for each structure and bias. The structure with one Mn impurity reveals a transfer characteristics suitable for a spin current switch. In the case of two Mn impurities, the system behaves as an efficient spin-filter device, independent on the ferromagnetic or antiferromagnetic configurations of the magnetic impurities. The experimental availability of the building blocks as well as the magnitudes of the obtained spin current polarizations indicates a strong potential of the analyzed structures for future spintronic devices.

  2. Connections between magnetism and superconductivity in UBe13 doped with thorium or boron

    International Nuclear Information System (INIS)

    Heffner, R.H.; Ott, H.R.; Schenck, A.; Mydosh, J.A.; MacLaughlin, D.E.

    1991-06-01

    Magnetism and superconductivity appear to be intimately connected in the heavy electron (HE) superconductors. For example, it has been conjectured but not proven that the exchange of antiferromagnetic spin fluctuations are responsible for pairing in HE superconductors. In this paper we review recent results in U 1-x Th x Be 13 , where specific heat, lower critical field and zero-field μSR measurements reveal another second-order phase transition to a state which possesses small-moment magnetic correlations for 0.019 ≤ x ≤ 0.043. We present a new phase diagram for (U,Th)Be 13 which indicates that the superconducting and magnetic order parameters are closely coupled. A discussion of the nature of the lower phase is presented, including the consideration of a possible magnetic superconducting state. When UBe 13 is doped with B (UBe 12.97 B 0.03 ) the Kondo temperature is decreased and the specific heat jump at the superconducting transition temperature is significantly enhanced. However, μSR measurements reveal no magnetic signature in UBe 12.97 B 0.03 , unlike the case for Th doping. The correlation between changes in the Kondo temperature and changes in the superconducting properties induced by B doping provide evidence for the importance of magnetic excitations in the superconducting pairing interaction in UBe 13

  3. AlTiN layer effect on mechanical properties of Ti-doped diamond-like carbon composite coatings

    International Nuclear Information System (INIS)

    Pang Xiaolu; Yang Huisheng; Gao Kewei; Wang Yanbin; Volinsky, Alex A.

    2011-01-01

    Ti/Ti-doped diamond-like carbon (DLC) and Ti/AlTiN/Ti-DLC composite coatings were deposited by magnetron sputtering on W18Cr4V high speed steel substrates. The effect of the AlTiN support layer on the properties of these composite coatings was investigated through microstructure and mechanical properties characterization, including hardness, elastic modulus, coefficient of friction and wear properties measured by scanning electron microscopy, Raman spectroscopy, scratch and ball-on-disk friction tests. Ti and AlTiN interlayers have a columnar structure with 50-80 nm grains. The hardness and elastic modulus of Ti/Ti-DLC and Ti/AlTiN/Ti-DLC coatings is 25.9 ± 0.4, 222.2 ± 6.3 GPa and 19.3 ± 1, 205.6 ± 6.7 GPa, respectively. Adhesion of Ti-DLC, Ti/AlTiN/Ti-DLC and AlTiN/Ti-DLC coatings expressed as the critical lateral force is 26.5 N, 38.2 N, and 47.8 N, respectively. Substrate coefficient of friction without coatings is 0.44, and it is 0.1 for Ti/Ti-DLC and Ti/AlTiN/Ti-DLC coatings. Wear resistance of Ti/AlTiN/Ti-DLC composite coatings is much higher than Ti/Ti-DLC coatings based on the wear track width of 169.8 and 73.2 μm, respectively, for the same experimental conditions.

  4. Adhesion and differentiation of Saos-2 osteoblast-like cells on chromium-doped diamond-like carbon coatings.

    Science.gov (United States)

    Filova, Elena; Vandrovcova, Marta; Jelinek, Miroslav; Zemek, Josef; Houdkova, Jana; Jan Remsa; Kocourek, Tomas; Stankova, Lubica; Bacakova, Lucie

    2017-01-01

    Diamond-like carbon (DLC) thin films are promising for use in coating orthopaedic, dental and cardiovascular implants. The problem of DLC layers lies in their weak layer adhesion to metal implants. Chromium is used as a dopant for improving the adhesion of DLC films. Cr-DLC layers were prepared by a hybrid technology, using a combination of pulsed laser deposition (PLD) from a graphite target and magnetron sputtering. Depending on the deposition conditions, the concentration of Cr in the DLC layers moved from zero to 10.0 at.%. The effect of DLC layers with 0.0, 0.9, 1.8, 7.3, 7.7 and 10.0 at.% Cr content on the adhesion and osteogenic differentiation of human osteoblast-like Saos-2 cells was assessed in vitro. The DLC samples that contained 7.7 and 10.0 at.% of Cr supported cell spreading on day 1 after seeding. On day three after seeding, the most apparent vinculin-containing focal adhesion plaques were also found on samples with higher concentrations of chromium. On the other hand, the expression of type I collagen and alkaline phosphatase at the mRNA and protein level was the highest on Cr-DLC samples with a lower concentration of Cr (0-1.8 at.%). We can conclude that higher concentrations of chromium supported cell adhesion; however DLC and DLC doped with a lower concentration of chromium supported osteogenic cell differentiation.

  5. Fabrication and electrochemistry characteristics of nickel-doped diamond-like carbon film toward applications in non-enzymatic glucose detection

    Science.gov (United States)

    Liu, Chi-Wen; Chen, Wei-En; Sun, Yin Tung Albert; Lin, Chii-Ruey

    2018-04-01

    This research work focused on the fabrication of nickel-doped diamond-like carbon (DLC) films and their characteristics including of surface morphology, microstructure, and electrochemical aiming at applications in non-enzymatic glucose detection. Novel nanodiamond target was employed in unbalanced magnetron radio-frequency co-sputtering process to prepared high quality Ni-doped DLC thin film at room temperature. TEM analysis reveals a highly uniform distribution of Ni crystallites in amorphous carbon matrix with fraction ranged from 3 to 11.5 at.% which is considered as active sites for the glucose detection. Our cyclic voltammetry measurements using 0.1 M H2SO4 solution demonstrated that the as-prepared Ni-doped DLC films possess large electrochemical potential window of 2.12 V, and this was also observed to be significantly reduced at high Ni doping level owing to lower sp3 fraction. The non-enzymatic glucose detection investigation indicates that the Ni-doped DLC thin film electrode prepared under 7 W of DC sputtering power on Ni target possesses good detecting performance, high stability, and high sensitivity to glucose concentration up to 10 mM, even with the existence of uric acid and ascorbic acid. The peak current was observed to be proportional to glucose concentration and scanning rate, demonstrating highly reversibility redox process of the film electrode and glucose.

  6. Facile Synthesis of Boron-Doped rGO as Cathode Material for High Energy Li–O 2 Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Feng [Beijing Key Laboratory; amp, Engineering, Beijing Institute of Technology, Beijing 100081, PR China; Collaborative Innovation Center; Xing, Yi [Beijing Key Laboratory; amp, Engineering, Beijing Institute of Technology, Beijing 100081, PR China; Li, Li [Beijing Key Laboratory; amp, Engineering, Beijing Institute of Technology, Beijing 100081, PR China; Collaborative Innovation Center; Qian, Ji [Beijing Key Laboratory; amp, Engineering, Beijing Institute of Technology, Beijing 100081, PR China; Qu, Wenjie [Beijing Key Laboratory; amp, Engineering, Beijing Institute of Technology, Beijing 100081, PR China; Wen, Jianguo [Electron Microscopy; Miller, Dean [Electron Microscopy; Ye, Yusheng [Beijing Key Laboratory; amp, Engineering, Beijing Institute of Technology, Beijing 100081, PR China; Chen, Renjie [Beijing Key Laboratory; amp, Engineering, Beijing Institute of Technology, Beijing 100081, PR China; Collaborative Innovation Center; Amine, Khalil [Chemical Science and Engineering Division, Argonne; Lu, Jun [Chemical Science and Engineering Division, Argonne

    2016-08-29

    To improve the electrochemical performance of the high energy Li–O2 batteries, it is important to design and construct a suitable and effective oxygen-breathing cathode. Herein, a three-dimensional (3D) porous boron-doped reduction graphite oxide (B-rGO) material with a hierarchical structure has been prepared by a facile freeze-drying method. In this design, boric acid as the boron source helps to form the 3D porous structure, owing to its cross-linking and pore-forming function. This architecture facilitates the rapid oxygen diffusion and electrolyte penetration in the electrode. Meanwhile, the boron–oxygen functional groups linking to the carbon surface or edge serve as additional reaction sites to activate the ORR process. It is vital that boron atoms have been doped into the carbon lattices to greatly activate the electrons in the carbon π system, which is beneficial for fast charge under large current densities. Density functional theory calculation demonstrates that B-rGO exhibits much stronger interactions with Li5O6 clusters, so that B-rGO more effectively activates Li–O bonds to decompose Li2O2 during charge than rGO does. With B-rGO as a catalytic substrate, the Li–O2 battery achieves a high discharge capacity and excellent rate capability. Moreover, catalysts could be added into the B-rGO substrate to further lower the overpotential and enhance the cycling performance in future.

  7. Potentiometric application of boron- and phosphorus-doped glassy carbon electrodes

    Directory of Open Access Journals (Sweden)

    ZORAN V. LAUSEVIC

    2001-03-01

    Full Text Available Acomparative study was carried out of the potentiometric application of boronand phosphorus-doped and undoped glassy carbon samples prepared at the same heat treatment temperature (HTT 1000°C. The electrochemical activities of the obtained electrode materials were investigated on the example of argentometric titrations. It was found that the electrochemical behaviour of the doped glassy carbon samples are very similar to a Sigri (undoped glassy carbon sample (HTT 2400°C. The experiments showed that the potentiometric response depends on the polarization mode, the nature of the sample, the pretreatment of the electrode surface, and the nature of the supporting electrolyte. The amounts of iodide, bromide, and of chloridewere determined to be 1.27 mg, 0.80 mg and 0.54 mg, respectively, with a maximum relative standard deviation of less than 1.1%. The obtained results are in good agreement with the results of comparative potentiometric titrations using a silver indicator electrode. The titrationmethod was applied to the indirect determination of pyridoxine hydrochloride, i.e., vitamin B6.

  8. Diamond: a material for acoustic devices

    OpenAIRE

    MORTET, Vincent; WILLIAMS, Oliver; HAENEN, Ken

    2008-01-01

    Diamond has been foreseen to replace silicon for high power, high frequency electronic applications or for devices that operates in harsh environments. However, diamond electronic devices are still in the laboratory stage due to the lack of large substrates and the complexity of diamond doping. On another hand, surface acoustic wave filters based on diamond are commercially available. Diamond is especially suited for acoustic applications because of its exceptional mechanical properties. The ...

  9. Modeling of helium bubble nucleation and growth in neutron irradiated boron doped RAFM steels

    International Nuclear Information System (INIS)

    Dethloff, Christian; Gaganidze, Ermile; Svetukhin, Vyacheslav V.; Aktaa, Jarir

    2012-01-01

    Reduced activation ferritic/martensitic (RAFM) steels are promising candidates for structural materials in future fusion technology. In addition to other irradiation defects, the transmuted helium is believed to strongly influence material hardening and embrittlement behavior. A phenomenological model based on kinetic rate equations is developed to describe homogeneous nucleation and growth of helium bubbles in neutron irradiated RAFM steels. The model is adapted to different 10 B doped EUROFER97 based heats, which already had been studied in past irradiation experiments. Simulations yield bubble size distributions, whereby effects of helium generation rate, surface energy, helium sinks and helium density are investigated. Peak bubble diameters under different conditions are compared to preliminary microstructural results on irradiated specimens. Helium induced hardening was calculated by applying the Dispersed Barrier Hardening model to simulated cluster size distributions. Quantitative microstructural investigations of unirradiated and irradiated specimens will be used to support and verify the model.

  10. Modeling of helium bubble nucleation and growth in neutron irradiated boron doped RAFM steels

    Energy Technology Data Exchange (ETDEWEB)

    Dethloff, Christian, E-mail: christian.dethloff@kit.edu [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Gaganidze, Ermile [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Svetukhin, Vyacheslav V. [Ulyanovsk State University, Leo Tolstoy Str. 42, 432970 Ulyanovsk (Russian Federation); Aktaa, Jarir [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2012-07-15

    Reduced activation ferritic/martensitic (RAFM) steels are promising candidates for structural materials in future fusion technology. In addition to other irradiation defects, the transmuted helium is believed to strongly influence material hardening and embrittlement behavior. A phenomenological model based on kinetic rate equations is developed to describe homogeneous nucleation and growth of helium bubbles in neutron irradiated RAFM steels. The model is adapted to different {sup 10}B doped EUROFER97 based heats, which already had been studied in past irradiation experiments. Simulations yield bubble size distributions, whereby effects of helium generation rate, surface energy, helium sinks and helium density are investigated. Peak bubble diameters under different conditions are compared to preliminary microstructural results on irradiated specimens. Helium induced hardening was calculated by applying the Dispersed Barrier Hardening model to simulated cluster size distributions. Quantitative microstructural investigations of unirradiated and irradiated specimens will be used to support and verify the model.

  11. Investigation of thermal stability and spectroscopic properties in Er3+ doped bismuth-boron-germanium glasses

    International Nuclear Information System (INIS)

    Nie Qiuhua; Lu Longjun; Dai Shixun; Xu Tiefeng; Shen Xiang; Zhang Xudong; Liang Xiaowei; Zhang Xianghua

    2007-01-01

    A series of Er 3+ -doped 50Bi 2 O 3 -(50-x)B 2 O 3 -xGeO 2 +0.5 wt% Er 2 O 3 (x=0, 5, 10, 15, 20 mol%) glasses were prepared. The thermal stability, absorption spectra, emission spectra and lifetime of the 4 I 13 / 2 level of Er 3+ ions were measured and studied. It is found that the absorption cross-section of Er 3+ , emission intensity and lifetime of the 4 I 13 / 2 level of Er 3+ increase with increasing GeO 2 content in the glass composition, while the fluorescence full-width at half-maximum (FWHM) at 1.5 μm of Er 3+ is about 79 nm in x=20 mol% glass sample under 970 nm pump. The obtained data suggest that this system glass can be used as a candidate host material for potential broadband optical amplifiers

  12. Zanamivir immobilized magnetic beads for voltammetric measurement of neuraminidase at gold-modified boron doped diamond electrode

    Energy Technology Data Exchange (ETDEWEB)

    Wahyuni, Wulan Tri, E-mail: wulantriws@gmail.com [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Bogor Agricultural University, Kampus IPB Darmaga, Bogor 16680 (Indonesia); Department of Chemistry, FMIPA, Universitas Indonesia, Kampus UI Depok (Indonesia); Ivandini, Tribidasari A.; Saepudin, Endang [Department of Chemistry, FMIPA, Universitas Indonesia, Kampus UI Depok (Indonesia); Einaga, Yasuaki [Department of Chemistry, Faculty of Science and Technology, Keio University, Hiyoshi 3-14-1, Yokohama 223-8522 (Japan); CREST, JST, 3-14-1 Hiyoshi, Yokohama 223-8522 (Japan)

    2016-04-19

    Biomolecule modified magnetic beads has been widely used in separation and sensing process. This study used streptavidin modified magnetic beads to immobilize biotin modified zanamivir. Biotin-streptavidin affinity facilitates immobilization of zanamivir on magnetic beads. Then interaction of zanamivir and neuraminidase was adopted as basic for enzyme detection. Detection of neuraminidase was performed at gold modified BDD using cyclic voltammetry technique. The measurement was carried out based on alteration of electrochemical signals of working electrode as neuraminidase response. The result showed that zanamivir was successfully immobilized on magnetic beads. The optimum amount of magnetic beads for zanamivir immobilization was 120 ug. Linear responses of neuraminidase were detected in concentration range of 0-15 mU. Detection limit (LOD) of measurement was 2.32 mU (R2 = 0.959) with precision as % RSD of 1.41%. Measurement of neuraminidase on magnetic beads could be also performed in the presence of mucin matrix. The linearity range was 0-8 mU with LOD of 0.64 mU (R2 = 0.950) and % RSD of 7.25%.

  13. Sensitive voltammetric method for the fast analysis of the antioxidant pyrogallol using a boron-doped diamond electrode in biofuels

    Czech Academy of Sciences Publication Activity Database

    Chýlková, J.; Tomášková, M.; Janíková, L.; Šelešovská, R.; Navrátil, Tomáš; Chudobová, I.

    2017-01-01

    Roč. 71, č. 6 (2017), s. 1047-1054 ISSN 0366-6352 Institutional support: RVO:61388955 Keywords : antioxidant * voltammetry * pyrogallol Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 1.258, year: 2016

  14. Boron doped bcc-W films: Achieving excellent mechanical properties and tribological performance by regulating substrate bias voltage

    Science.gov (United States)

    Yang, Lina; Zhang, Kan; Zeng, Yi; Wang, Xin; Du, Suxuan; Tao, Chuanying; Ren, Ping; Cui, Xiaoqiang; Wen, Mao

    2017-11-01

    Boron doped bcc-W (WBx, x = B/W) films were deposited on Si(100) substrates by magnetron co-sputtering pure W and B targets. Our results reveal that when the absolute value of substrate bias voltage (Vb) increases from floating to 240 V, the value of x monotonously decreases from 0.18 to 0.04, accompanied by a phase transition from a mixture of tetragonal γ-W2B and body-centered cubic α-W(B) phase (-Vb ≤ 60 V) to α-W(B) single phase (-Vb > 60 V). Hardness, depending on Vb, increases first and then drops, where the maximum hardness of 30.8 GPa was obtained at -Vb = 60 V and far higher than pure W and W2B theoretical value. In the mixed phase structure, the grain boundaries strengthening, Hall-Petch effect and solid-solution strengthening induced by B dominate the strengthening mechanism. Astonishingly, the film grown at -Vb = 120 V still possesses twice higher hardness than pure W, wherein unexpectedly low (6.7 at.%) B concentration and only the single α-W(B) phase can be identified. In this case, both Hall-Petch effect and solid-solution strengthening work. Besides, low friction coefficient of ∼0.18 can be obtained for the films with α-W(B) phase, which is competitive to that of reported B-rich transition-metal borides, such as TiB2, CrB and CrB2.

  15. 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.

  16. Elastic properties of ultrathin diamond/AlN membranes

    Energy Technology Data Exchange (ETDEWEB)

    Zuerbig, V., E-mail: verena.zuerbig@iaf-extern.fraunhofer.de [Fraunhofer Institute for Applied Solid State Physics IAF, Tullastr. 72, 79108 Freiburg (Germany); IMTEK, University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg (Germany); Hees, J.; Pletschen, W.; Sah, R.E.; Wolfer, M.; Kirste, L.; Heidrich, N.; Nebel, C.E. [Fraunhofer Institute for Applied Solid State Physics IAF, Tullastr. 72, 79108 Freiburg (Germany); Ambacher, O. [Fraunhofer Institute for Applied Solid State Physics IAF, Tullastr. 72, 79108 Freiburg (Germany); IMTEK, University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg (Germany); Lebedev, V. [Fraunhofer Institute for Applied Solid State Physics IAF, Tullastr. 72, 79108 Freiburg (Germany)

    2014-05-02

    Nanocrystalline diamond- (NCD) and AlN-based ultrathin single layer and bilayer membranes are investigated towards their mechanical properties. It is shown that chemo-mechanical polishing and heavy boron doping of NCD thin films do not impact the elastic properties of NCD layers as revealed by negligible variations of the NCD Young's modulus (E). In addition, it is demonstrated that the combination of NCD elastic layer and AlN piezo-actuator is highly suitable for the fabrication of mechanically stable ultrathin membranes in comparison to AlN single layer membranes. The elastic parameters of NCD/AlN heterostructures are mainly determined by the outstanding high Young's modulus of NCD (E = 1019 ± 19 GPa). Such ultrathin unimorph membranes allow for fabrication of piezo-actuated AlN/NCD microlenses with tunable focus length. - Highlights: • Mechanical properties of nanocrystalline diamond (NCD) and AlN circular membranes • No influence of polishing of NCD thin films on the mechanical properties of NCD • No influence of heavy boron-doping on the mechanical properties of NCD • Demonstration of mechanically stable piezo-actuated NCD/AlN membranes • Reported performance of AlN/NCD microlenses with adjustable focus length.

  17. Space-Confined Synthesis of Three-Dimensional Boron/Nitrogen-Doped Carbon Nanotubes/Carbon Nanosheets Line-in-Wall Hybrids and Their Electrochemical Energy Storage Applications

    DEFF Research Database (Denmark)

    Zhu, Shan; Li, Jiajun; Li, Qingfeng

    2016-01-01

    and CNTs in this unique pattern, the LIW-NB integrates advantages of three aspects: first, the doped heteroatoms enhancing electrochemical properties of carbon matrix; second, the warp-proof nanosheets supplying high specific surface area; and the extracted and embedded CNTs serving as electron conductive...... paths and reinforcing the whole architecture. As a result, the 3D LIW-NB shows excellent electrochemical properties: as the electrode of supercapacitors, LIW-NB exhibits high specific capacity at different current densities (389 F g-1 at 1 A g-1 and 129 F g-1 at 20 Ag-1); as the lithium ion battery......This research demonstrates a flexible one-pot strategy for fabricating three-dimensional (3D) boron/nitrogen-doped networks of carbon nanotubes(CNTs)/carbon nanosheets "Line-in-Wall" hybrids (LIWNB) based on the space-confined template method. In the synthesis, the high rate of freezing step...

  18. Influence of W content on tribological performance of W-doped diamond-like carbon coatings under dry friction and polyalpha olefin lubrication conditions

    International Nuclear Information System (INIS)

    Fu, Zhi-qiang; Wang, Cheng-biao; Zhang, Wei; Wang, Wei; Yue, Wen; Yu, Xiang; Peng, Zhi-jian; Lin, Song-sheng; Dai, Ming-jiang

    2013-01-01

    Highlights: • W-doped DLC coating with various W contents was fabricated. • Friction and wear of DLC coated sample was studied. • The lubricant additive was T307. • The influence of W content on friction under lubrication was unveiled. • The influence of W content on wear under lubrication was studied. - Abstract: The influence on tungsten content on the structure, mechanical properties and tribological performance of W-doped diamond-like carbon (DLC) coatings was studied by X-ray photoelectron spectroscopy, nano-indentation, scratch test, and ball-on-disk friction test. It was found that with increasing W content, the content of WC and free W in the coatings is increased while the content of sp 3 -C in the coatings is decreased. The effect of W content on the hardness and elastic modulus of the coatings is indistinctive, but there exists the highest critical load of scratch test of above 100 N when W content is 3.08 at.%. With the increase of W content, the friction coefficients of W-doped DLC coatings under dry friction conditions are increased while the friction coefficients of W-doped DLC coatings under polyalpha olefin (PAO) lubrication are decreased. With the increase of W content, the wear rates of the DLC-coated samples under dry friction conditions show a minimum value; under pure PAO lubrication, the influence of W content on the wear rates of the DLC-coated samples is indistinctive when the W content is below 10.73 at.% while the wear rates are increased with increasing W content from 10.73 at.% to 24.09 at.%; when lubricated by PAO + thiophosphoric acid amine (T307) salt, the samples coated with the undoped DLC or the W-doped DLC with high W content exhibit low wear rates

  19. Electrolyzing synthesis of boron-doped graphene quantum dots for fluorescence determination of Fe3+ions in water samples.

    Science.gov (United States)

    Chen, Li; Wu, Chuanli; Du, Pan; Feng, Xiaowei; Wu, Ping; Cai, Chenxin

    2017-03-01

    This work reports a facile electrolyzing method to synthesize boron-doped graphene quantum dots (BGQDs) and uses the BGQDs as a fluorescent probe to determine Fe 3+ ion levels in water samples. The BGQDs were produced by oxidizing graphite in an aqueous borax solution at pH 7; then, the borate solution was filtered with BGQDs, and the borate was dialyzed from the filtrate, leaving a solution of BGQDs in water. The amount of the B in the BGQDs can be adjusted by changing the concentration of borax used for the electrolyte. The excitation wavelength- and B amount-dependent fluorescence characteristics of BQGDs were studied. The fluorescence intensity of the BGQDs is measurable in real time, and its quenching is very sensitive to the concentration of Fe 3+ ions in the system but not to other possible coexisting metal ions. The fluorescence quenching mechanism of Fe 3+ ions to BGQDs is studied and explained based on electrochemical voltammetry and DFT simulations. The analytical signal, which is defined as F 0 /F, where F 0 and F are the fluorescence intensities of the BGQDs before and after interaction with Fe 3+ ions, respectively, displays a good linear relationship in the Fe 3+ ion concentration range of 0.01-100µm with a correlation coefficient of 0.999 and a limit of detection (LOD) of ~(0.005±0.001) μM. The LOD value is much lower than the water quality standards for Fe 3+ ions (0.3ppm, ~5.36µm) in drinking water suggested by the WHO (World Health Organization) and EPA (U.S. Environmental Protection Agency), implying that this method has great potential for applications in real sample assays. For example, the determination of the Fe 3+ ion levels in three water samples (tap water, groundwater, and lake water) gives approximately the same results as those determined by the EPA-recommended AAS (atomic adsorption spectroscopy) method. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Effects of bimetallic doping on small cyclic and tubular boron clusters: B7M2 and B14M2 structures with M = Fe, Co.

    Science.gov (United States)

    Pham, Hung Tan; Nguyen, Minh Tho

    2015-07-14

    Using density functional theory with the TPSSh functional and the 6-311+G(d) basis set, we extensively searched for the global minima of two metallic atoms doped boron clusters B6M2, B7M2, B12M2 and B14M2 with transition metal element M being Co and Fe. Structural identifications reveal that B7Co2, B7Fe2 and B7CoFe clusters have global minima in a B-cyclic motif, in which a perfectly planar B7 is coordinated with two metallic atoms placed along the C7 axis. The B6 cluster is too small to form a cycle with the presence of two metals. Similarly, the B12 cluster is not large enough to stabilize the metallic dimer within a double ring 2 × B6 tube. The doped B14M2 clusters including B14Co2, B14Fe2 and B14CoFe have a double ring 2 × B7 tubular shape in which one metal atom is encapsulated by the B14 tube and the other is located at an exposed position. Dissociation energies demonstrate that while bimetallic cyclic cluster B7M2 prefers a fragmentation channel that generates the B7 global minimum plus metallic dimer, the tubular structure B14M2 tends to dissociate giving a bimetallic cyclic structure B7M2 and a B@B6 cluster. The enhanced stability of the bimetallic doped boron clusters considered can be understood from the stabilizing interactions between the anti-bonding MOs of metal-metal dimers and the levels of a disk aromatic configuration (for bimetallic cyclic structures), or the eigenstates of the B14 tubular form (in case of bimetallic tubular structure).

  1. Tl and OSL dosimetry of diamond films CVD pure and unpurified with boron-carbon; Dosimetria Tl y OSL de peliculas de diamante CVD puras e impurificadas con boro-carbono

    Energy Technology Data Exchange (ETDEWEB)

    Melendrez, R.; Pedroza M, M.; Chernov, V.; Ochoa N, J.D.; Bernal, R.; Barboza F, M. [CIF, UNISON, A.P. 5-088, 83190 Hermosillo, Sonora (Mexico); Castaneda, B. [Departamento de Fisica, Universidad de Sonora, Apdo. Postal 1626, Hermosillo, Sonora (Mexico); Goncalves, J.A.N.; Sandonato, G.M. [Laboratorio Associado de Plasma, Instituto Nacional de Pesquisas Espaciais C.P. 515- 12201 -970, Sao Jose dos Campos, SP (Brazil); Cruz Z, E. [Instituto de Ciencias Nucleares, UNAM, Apdo. Postal 70-543, 04510 Mexico D.F. (Mexico); Preciado F, S.; Cruz V, C.; Brown, F. [Departamento de Investigacion en Polimeros y Materiales de la Universidad de Sonora, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Schreck, M. [Universitaet Augsburg, Institut fuer Physik D-86135 Augsburg (Germany)

    2004-07-01

    The diamond is a material that possesses extreme physical properties, such as its hardness to the radiation, its low chemical reactivity besides its equivalence to the human tissue, which qualify him as an ideal material for radiation dosimetry. In this work, it was studied the thermal and optically stimulated response (Tl and OSL) of polycrystalline diamond films grown by the technique of CVD pure and contaminated with Boron-carbon (B/C) with the intention of characterizing their efficiency like a dosemeter for radiation in a range of 0 - 3000 Gy. For the case of the films without impurities, the Tl curve presents four main peaks, two of them in an interval of temperatures of 150-200 C and other two additional around of 250-400 C. The dependence of the response of integrated Tl and that of OSL always maintained a lineal relationship with the exhibition dose up to 100 Gy. The behavior of the films contaminated with B/C (2000 - 20000 ppm) was established through experiments that involved the signal of OSL and their relationship with the Tl response. It was found that this processes are correlated, since the electrons caught in the traps of low temperature (50 - 250 C) of the Tl they are the electrons that recombining with more probability to provide the signal of OSL. According to these results it is possible to propose the diamond films as a good candidate for dosimetry to, using the traditional technique of Tl so much as well as the but recent of OSL. (Author)

  2. Large diamonds grown at high pressure conditions

    CERN Document Server

    Kanda, H

    2000-01-01

    A technique has been established to grow large diamonds up to 2 cm. The crystals are bulky polyhedron with yellow, blue, green or brown color as well as colorless, which depend on impurities. The impurities incorporated into the diamond are limited, i.e. nitrogen, boron, nickel, cobalt, silicon and phosphorus.

  3. 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

    diamond's exceptional properties for quantum information processing [2], a topic on which there have been many recent papers, and where a diamond colour centre single photon source is already commercially available. Biomedical applications of diamond are recognised, partly tribological and partly electrochemical, but lie outside the present group of papers. Processing and controlling diamond surfaces and interfaces with other materials in their environment are critical steps en route to exploitation. Boron-doped diamond has already found application in electro-analysis and in the bulk oxidation of dissolved species in solution [3]. Energy-related applications—ranging from high-power electronics [3] to a potential first wall of fusion reactors [4]—are further exciting potential applications. Even small and ugly diamonds have value. Their mechanical properties [5] dominate, with significant niche applications such as thermal sinks. The major applications for diamond to date exploit only a fraction of diamond's special properties: visual for status diamonds, and mechanical for working diamonds. Diamond physics reaches well beyond the usual laboratory, to the geological diamond formation processes in the Earth's mantle. Characterization of natural gem diamonds [6, 7] is one part of the detective story that allows us to understand the conditions under which they formed. It was only half a century ago that the scientific and technological challenges of diamond synthesis were met systematically. Today, most of the recent research on diamond has concentrated on synthetics, whether created using high pressure, high temperature (HPHT) techniques or chemical vapour deposition (CVD). The HPHT synthesis of diamond has advanced dramatically [8, 9] to the extent that dislocation birefringence [10] can be largely eliminated. In silicon technology, the elimination of dislocations was a major step in microelectronics. Now, even diamond can be synthesised containing virtually no

  4. Computational designing ultra-sensitive nano-composite based on boron doped and CuO decorated graphene to adsorb H2S and CO gaseous molecules

    Science.gov (United States)

    Asadi, Hamed; Vaezzadeh, Majid

    2017-07-01

    In this paper, interactions of carbon monoxide (CO) and hydrogen sulfide (H2S) with doped and decorated graphene were investigated by using density functional theory and quantum-espresso packages. First of all, impurity effects and properties like adsorption mechanism, the more probable position, binding energy, bond length, Lowdin charge analyze and density of state (DOS) have been determined and then the properties of CO and H2S adsorption calculated, and a brief comparison with other studies has been done. All of these lead to tuning the electronic structure of graphene sheet with impurities that show higher affinities with H2S and CO molecules in comparison to pristine graphene. The obtained results from DOS and charge transfer show that electrical conductance of the B doped graphene sheet and CuO Nano particle decorated—Boron doped graphene sheets are significantly changed compared to the pristine graphene sheet by an increase in the electronic states of near the Fermi’s energy states.

  5. Growth of diamond layers on diamond and cBN seeds using iron carbide under high pressure and high temperature

    CERN Document Server

    Li Xun; Hao Zhao Yin; LiuPeng; Li Musen; Zou Guang Tian; Cheng Shu Yu; Cheng Kai Jia

    2002-01-01

    Iron carbide without any graphite was studied under high pressure and high temperature (HPHT); diamond layers were obtained both on diamond and on cubic boron nitride seeds at 5.5 GPa and 1700-1750 K. The results showed that transition-metal carbide was the main intermediate in the course of the transformation from graphite to diamond under HPHT.

  6. Low-temperature magnetoresistance study of electrical transport in N- and B-doped ultrananocrystalline and nanocrystalline diamond films

    Czech Academy of Sciences Publication Activity Database

    Nesládek, M.; Tromson, D.; Bergonzo, P.; Hubík, Pavel; Mareš, Jiří J.; Krištofik, Jozef; Kindl, Dobroslav; Williams, O.A.; Gruen, D.

    2006-01-01

    Roč. 15, - (2006), s. 607-613 ISSN 0925-9635 R&D Projects: GA AV ČR(CZ) IAA1010404; GA ČR(CZ) GA202/06/0040 Institutional research plan: CEZ:AV0Z10100521 Keywords : U-NCD * NCD * doping * low-temperature doping * weak localisation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.935, year: 2006

  7. Photoluminescence properties of arsenic and boron doped Si3N4 nanocrystal embedded in SiN x O y matrix

    Science.gov (United States)

    Puglia, Denise; Sombrio, Guilherme; dos Reis, Roberto; Boudinov, Henri

    2018-03-01

    Photoluminescence emission of Si3N4 nanocrystals embedded in SiN x O y matrices was investigated. Nanocrystals were grown by annealing of silicon oxynitride films deposited by sputtering, passivated in forming gas atmosphere and implanted with boron and arsenic. Emission energy was tuned from green to ultraviolet by changing the composition of SiN x O y matrices. Structural characterization of the nanocrystals was performed by Transmission Electron Microscopy. Photoluminescence at room and low temperatures was analyzed and the results suggest that light emission originates in the interface between the nanocrystals and the matrix. The highest photoluminescence intensity at room temperature was achieved by arsenic doped silicon oxynitride films deposited with an excess of nitrogen.

  8. Endo-Fullerene and Doped Diamond Nanocrystallite Based Models of Qubits for Solid-State Quantum Computers

    Science.gov (United States)

    Park, Seongjun; Srivastava, Deepak; Cho, Kyeongjae; Biegel, Bryan (Technical Monitor)

    2001-01-01

    Models of encapsulated 1/2 nuclear spin H-1 and P-31 atoms in fullerene and diamond nanocrystallite, respectively, are proposed and examined with ab-initio local density functional method for possible applications as single quantum bits (qubits) in solid-state quantum computers. A H-1 atom encapsulated in a fully deuterated fullerene, C(sub 20)D(sub 20), forms the first model system and ab-initio calculation shows that H-1 atom is stable in atomic state at the center of the fullerene with a barrier of about 1 eV to escape. A P-31 atom positioned at the center of a diamond nanocrystallite is the second model system, and 3 1P atom is found to be stable at the substitutional site relative to interstitial sites by 15 eV, Vacancy formation energy is 6 eV in diamond so that substitutional P-31 atom will be stable against diffusion during the formation mechanisms within the nanocrystallite. The coupling between the nuclear spin and weakly bound (valance) donor electron coupling in both systems is found to be suitable for single qubit applications, where as the spatial distributions of (valance) donor electron wave functions are found to be preferentially spread along certain lattice directions facilitating two or more qubit applications. The feasibility of the fabrication pathways for both model solid-state qubit systems within practical quantum computers is discussed with in the context of our proposed solid-state qubits.

  9. Negligible Electronic Interaction between Photoexcited Electron-Hole Pairs and Free Electrons in Phosphorus-Boron Co-Doped Silicon Nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Limpens, Rens [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Neale, Nathan R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Fujii, Minoru [Kobe University; Gregorkiewicz, Tom [University of Amsterdam

    2018-03-05

    Phosphorus (P) and boron (B) co-doped Si nanocrystals (NCs) have raised interest in the optoelectronic industry due to their electronic tunability, optimal carrier multiplication properties, and straightforward dispersibility in polar solvents. Yet a basic understanding of the interaction of photoexcited electron-hole (e-h) pairs with new physical features that are introduced by the co-doping process (free carriers, defect states, and surface chemistry) is missing. Here, we present the first study of the ultrafast carrier dynamics in SiO2-embedded P-B co-doped Si NC ensembles using induced absorption spectroscopy through a two-step approach. First, the induced absorption data show that the large fraction of the dopants residing on the NC surface slows down carrier relaxation dynamics within the first 20 ps relative to intrinsic (undoped) Si NCs, which we interpret as enhanced surface passivation. On longer time-scales (picosecond to nanosecond regime), we observe a speeding up of the carrier relaxation dynamics and ascribe it to doping-induced trap states. This argument is deduced from the second part of the study, where we investigate multiexciton interactions. From a stochastic modeling approach we show that localized carriers, which are introduced by the P or B dopants, have minor electronic interactions with the photoexcited e-h pairs. This is understood in light of the strong localization of the introduced carriers on their original P- or B-dopant atoms, due to the strong quantum confinement regime in these relatively small NCs (<6 nm).

  10. Influence of duty ratio of pulsed bias on structure and properties of silicon-doped diamond-like carbon films by plasma deposition

    International Nuclear Information System (INIS)

    Nakazawa, Hideki; Kamata, Ryosuke; Miura, Soushi; Okuno, Saori

    2013-01-01

    We have investigated the influence of the duty ratio of pulsed substrate bias on the structure and properties of Si-doped diamond-like carbon (Si-DLC) films deposited by radio frequency plasma-enhanced chemical vapor deposition using CH 4 , Ar, and monomethylsilane (CH 3 SiH 3 ) as the Si source. The Si/(Si + C) ratios in the Si-DLC films deposited using pulsed bias were higher than that of the dc-biased Si-DLC film, and the Si fraction increased with decreasing pulse duty ratio. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses revealed that Si-C, Si-H n , and C-H n bonds in the Si-DLC films increased with decreasing duty ratio. The internal stress decreased as the duty ratio decreased, which is probably due to the increase in Si-C, Si-H n , and C-H n bonds in the films. The Si-DLC films deposited using pulsed bias had higher adhesion strength than the dc-biased Si-DLC film because of the further reduction of internal stress. At higher duty ratios, although the Si fractions of the pulse-biased Si-DLC films were higher than that of the dc-biased Si-DLC film, the wear rates of the former were less than that of the latter. - Highlights: • The internal stress of Si-doped films was lowered at lower duty ratios. • The adhesion of pulse-biased films was improved compared with that of dc films. • The tribological properties of Si-doped films were improved by the use of pulse bias

  11. Microstructure and property of diamond-like carbon films with Al and Cr co-doping deposited using a hybrid beams system

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Wei, E-mail: popdw@126.com [School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Liu, Jingmao; Geng, Dongsen [School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Guo, Peng [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Zheng, Jun [Science and Technology on Surface Engineering Laboratory, Lanzhou Institute of Physics, Lanzhou 730000 (China); Wang, Qimin, E-mail: qmwang@gdut.edu.cn [School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006 (China)

    2016-12-01

    Highlights: • Diamond-like carbon films with Al and Cr doping were deposited. • Alternate multilayered structure consisted of Al-poor layer and Al-rich layer was formed. • The periodic Al-rich layers can greatly improve the residual stress and elastic resilience of the films. - Abstract: DLC films with weak carbide former Al and carbide former Cr co-doping (Al:Cr-DLC) were deposited by a hybrid beams system comprising an anode-layer linear ion beam source (LIS) and high power impulse magnetron sputtering using a gas mixture of C{sub 2}H{sub 2} and Ar as the precursor. The doped Al and Cr contents were controlled via adjusting the C{sub 2}H{sub 2} fraction in the gas mixture. The composition, microstructure, compressive stress, mechanical properties and tribological behaviors of the Al:Cr-DLC films were researched carefully using X-ray photoelectron spectroscopy, transmission electron microscopy, Raman spectroscopy, stress-tester, nanoindentation and ball-on-plate tribometer as function of the C{sub 2}H{sub 2} fraction. The results show that the Al and Cr contents in the films increased continuously as the C{sub 2}H{sub 2} fraction decreased. The doped Cr atoms preferred to bond with the carbon while the Al atoms mainly existed in metallic state. Structure modulation with alternate multilayer consisted of Al-poor DLC layer and Al-rich DLC layer was found in the films. Those periodic Al-rich DLC layers can effectively release the residual stress of the films. On the other hand, the formation of the carbide component due to Cr incorporation can help to increase the film hardness. Accordingly, the residual stress of the DLC films can be reduced without sacrificing the film hardness though co-doping Al and Cr atoms. Furthermore, it was found that the periodic Al-rich layer can greatly improve the elastic resilience of the DLC films and thus decreases the film friction coefficient and wear rate significantly. However, the existence of the carbide component would

  12. Mesoscale Modeling of Dynamic Compression of Boron Carbide Polycrystals

    Science.gov (United States)

    2013-05-01

    occurs in ballistic impact, and accompanies amorphization in diamond anvil cell (DAC) experiments (Yan et al., 2009). Fracture in boron carbide ...Mesoscale Modeling of Dynamic Compression of Boron Carbide Polycrystals by J. D. Clayton ARL-RP-440 May 2013...Ground, MD 21005-5069 ARL-RP-440 May 2013 Mesoscale Modeling of Dynamic Compression of Boron Carbide Polycrystals J. D. Clayton

  13. Formation of ohmic contacts to p-type diamond using carbide forming metals

    Science.gov (United States)

    Nakanishi, Jiro; Otsuki, A.; Oku, T.; Ishiwata, O.; Murakami, Masanori

    1994-08-01

    The measurement of the specific contact resistance, rho(sub C), and microstructural analysis at the metal/diamond interface were carried out for diamond with various acceptor concentrations, N(sub A), in order to understand the carrier transport mechanism at the metal/diamond interface. The rho(sub C) measurements were carried out for polycrystalline boron-doped semiconducting diamonds which were prepared by the microwave plasma chemical vapor deposition. The acceptor concentrations, estimated by the boron concentrations measured by secondary ion mass spectroscopy, ranged from 3 x 10(exp 18) to 3 x 10(exp 20)/cu cm. Ti and Mo films, which form carbides with diamond, were deposited on the diamonds using the electron-beam evaporation technique. The rho(sub C) values were measured by the cricular transmission line method before and after annealing at temperatures in the range of 400-600 C. The dependence of the rho(sub C) values on the acceptor concentrations suggested that the dominant transport mechanism was the field-emission for the diamond with N(sub A) around 10(exp 20)/cu cm and the thermionic-field-emission for the diamond with N(sub A) from 3 x 10(exp 18)/cu cm to 4 x 10(exp 19)/cu cm. The rho(sub C) values of the Ti contacts were observed to decrease upon annealing, whereas those of the Mo contacts decreased gradually with increasing annealing temperature. However, the rho(sub C) values of both the Ti and Mo contacts reached at the same value of approximately 1 x 10(exp -6) Ohm sq cm after annealing at 600 C for the diamonds with N(sub A) higher than 10(exp 20)/cu cm. Note that the rho(sub C) values of the Mo contact were extremely stable at high temperatures: the rho(sub C) values did not deteriorate after annealing at 600 C for more than 3 h. The thermally stable molybdenum carbide (alpha-Mo2C) and amorphous layers were observed at the Mo/diamond interface after annealing at 600 C by cross-sectional transmission electron microscopy and x-ray diffraction.

  14. Metal-doped graphene layers composed with boron nitride-graphene as an insulator: a nano-capacitor.

    Science.gov (United States)

    Monajjemi, Majid

    2014-11-01

    A model of a nanoscale dielectric capacitor composed of a few dopants has been investigated in this study. This capacitor includes metallic graphene layers which are separated by an insulating medium containing a few h-BN layers. It has been observed that the elements from group IIIA of the periodic table are more suitable as dopants for hetero-structures of the {metallic graphene/hBN/metallic graphene} capacitors compared to those from groups IA or IIA. In this study, we have specifically focused on the dielectric properties of different graphene/h-BN/graphene including their hetero-structure counterparts, i.e., Boron-graphene/h-BN/Boron-graphene, Al-graphene/h-BN/Al-graphene, Mg-graphene/h-BN/Mg-graphene, and Be-graphene/h-BN/Be-graphene stacks for monolayer form of dielectrics. Moreover, we studied the multi dielectric properties of different (h-BN)n/graphene hetero-structures of Boron-graphene/(h-BN)n/Boron-graphene.

  15. Synchrotron Bragg diffraction imaging characterization of synthetic diamond crystals for optical and electronic power device applications.

    Science.gov (United States)

    Tran Thi, Thu Nhi; Morse, J; Caliste, D; Fernandez, B; Eon, D; Härtwig, J; Barbay, C; Mer-Calfati, C; Tranchant, N; Arnault, J C; Lafford, T A; Baruchel, J

    2017-04-01

    Bragg diffraction imaging enables the quality of synthetic single-crystal diamond substrates and their overgrown, mostly doped, diamond layers to be characterized. This is very important for improving diamond-based devices produced for X-ray optics and power electronics applications. The usual first step for this characterization is white-beam X-ray diffraction topography, which is a simple and fast method to identify the extended defects (dislocations, growth sectors, boundaries, stacking faults, overall curvature etc. ) within the crystal. This allows easy and quick comparison of the crystal quality of diamond plates available from various commercial suppliers. When needed, rocking curve imaging (RCI) is also employed, which is the quantitative counterpart of monochromatic Bragg diffraction imaging. RCI enables the local determination of both the effective misorientation, which results from lattice parameter variation and the local lattice tilt, and the local Bragg position. Maps derived from these parameters are used to measure the magnitude of the distortions associated with polishing damage and the depth of this damage within the volume of the crystal. For overgrown layers, these maps also reveal the distortion induced by the incorporation of impurities such as boron, or the lattice parameter variations associated with the presence of growth-incorporated nitrogen. These techniques are described, and their capabilities for studying the quality of diamond substrates and overgrown layers, and the surface damage caused by mechanical polishing, are illustrated by examples.

  16. Microstructure and high-temperature tribological properties of Si-doped hydrogenated diamond-like carbon films

    Science.gov (United States)

    Zhang, Teng Fei; Wan, Zhi Xin; Ding, Ji Cheng; Zhang, Shihong; Wang, Qi Min; Kim, Kwang Ho

    2018-03-01

    Si-doped DLC films have attracted great attention for use in tribological applications. However, their high-temperature tribological properties remain less investigated, especially in harsh oxidative working conditions. In this study, Si-doped hydrogenated DLC films with various Si content were synthesized and the effects of the addition of Si on the microstructural, mechanical and high-temperature tribological properties of the films were investigated. The results indicate that Si doping leads to an obvious increase in the sp3/sp2 ratio of DLC films, likely due to the silicon atoms preferentially substitute the sp2-hybridized carbon atoms and augment the number of sp3 sites. With Si doping, the mechanical properties, including hardness and adhesion strength, were improved, while the residual stress of the DLC films was reduced. The addition of Si leads to higher thermal and mechanical stability of DLC films because the Si atoms inhibit the graphitization of the films at an elevated temperature. Better high-temperature tribological properties of the Si-DLC films under oxidative conditions were observed, which can be attributed to the enhanced thermal stability and formation of a Si-containing lubricant layer on the surfaces of the wear tracks. The nano-wear resistance of the DLC films was also improved by Si doping.

  17. Influence of Pyrazine Ring Doping on the 15N and 11B NMR and Electronic Structure Parameters in Zigzag Boron Nitride Nanotube: A DFT Study

    Directory of Open Access Journals (Sweden)

    Sattar Arshadi

    2013-01-01

    Full Text Available Density functional theory (DFT calculations have been performed to investigate the properties of the electronic structures of pyrazine-doped boron nitride nanotubes (PD-BNNTs. The structural forms were firstly optimized and then nuclear magnetic resonance (NMR parameters have been calculated on the optimized structures. The chemical shielding isotropic ( and chemical shielding anisotropic ( parameters were calculated at the sites of 11B and 15N nuclei in structural forms of BNNT including the perfect (a model and PD-BNNTs (b, (c, and (d models. The results indicated that the changes are most significant for those nuclei placed in the nearest neighborhood of the pyrazine-doped ring. The changes of the electronic sites of the N atoms are also more significant than those of the B atoms. The difference of LUMO-HOMO gap for the perfect model was larger than the PD-BNNTs models. Also the atomic charge distribution of N and B atoms has been determined in nanotubes by natural bond orbital (NBO analysis. All calculations were performed by the B3LYP method and 6-311G** basis set using Gaussian 98 package of program.

  18. Boron, bismuth co-doping of gallium arsenide and other compounds for photonic and heterojunction bipolar transistor devices

    Science.gov (United States)

    Mascarenhas, Angelo

    2015-07-07

    Isoelectronic co-doping of semiconductor compounds and alloys with acceptors and deep donors is sued to decrease bandgap, t