Electrochemical properties of N-doped hydrogenated amorphous carbon films fabricated by plasma-enhanced chemical vapor deposition methods

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• 作者：Yoriko Tanaka ; Masahiro Furuta ; Koichi Kuriyama ; Ryosuke Kuwabara ; Yukiko Katsuki ; Takeshi Kondo ; Akira Fujishima ; Kensuke Honda
• 关键词：Nitrogen-doped hydrogenated amorphous carbon ; Plasma-enhanced chemical vapor deposition ; Electrochemical properties
• 刊名：Electrochimica Acta
• 出版年：2011
• 出版时间：1 January 2011
• 年：2011
• 卷：56
• 期：3
• 页码：1172-1181
• 全文大小：696 K

文摘

Nitrogen-doped hydrogenated amorphous carbon thin films (a-C:N:H, N-doped DLC) were synthesized with microwave-assisted plasma-enhanced chemical vapor deposition widely used for DLC coating such as the inner surface of PET bottles. The electrochemical properties of N-doped DLC surfaces that can be useful in the application as an electrochemical sensor were investigated. N-doped DLC was easily fabricated using the vapor of nitrogen contained hydrocarbon as carbon and nitrogen source. A N/C ratio of resulting N-doped DLC films was 0.08 and atomic ratio of sp³/sp²-bonded carbons was 25/75. The electrical resistivity and optical gap were 0.695 Ω cm and 0.38 eV, respectively. N-doped DLC thin film was found to be an ideal polarizable electrode material with physical stability and chemical inertness. The film has a wide working potential range over 3 V, low double-layer capacitance, and high resistance to electrochemically induced corrosion in strong acid media, which were the same level as those for boron-doped diamond (BDD). The charge transfer rates for the inorganic redox species, Fe^2+/3+ and Fe(CN)₆^4−/3− at N-doped DLC were sufficiently high. The redox reaction of Ce^2+/3+ with standard potential higher than H₂O/O₂ were observed due to the wider potential window. At N-doped DLC, the change of the kinetics of Fe(CN)₆^3−/4− by surface oxidation is different from that at BDD. The rate of Fe(CN)₆^3−/4− was not varied before and after oxidative treatment on N-doped DLC includes sp² carbons, which indicates high durability of the electrochemical activity against surface oxidation.