The Physicochemical and Electrochemical Properties of 100 and 500 nm Diameter Diamond Powders Coated with Boron-Doped Nanocrystalline Diamond

摘要: There is a need for advanced, corrosion-resistant electrocatalyst support materials use in fuel cells. To this end, electrically conducting diamond powder was prepared by depositing layer of boron-doped nanocrystalline on 100 and 500 nm diam powders. The doped deposited microwave plasma-assisted chemical vapor deposition using an Ar-rich CH 4 /H 2 /Ar/B H 6 source gas mixture. After coating, the had specific surface area 27 m /g electrical conductivity 0.41 S/cm. 8 0.59 S/cm after coating. both powders decreased ca. 50% coating due mainly to particle-particle fusion. measurements provided conclusive evidence overlayer as uncoated possessed no conductivity. Furthermore, fact that properties were unaltered acid washing confirmed arises from not any adventitious sp carbon impurity particle surface, which removed such treatment. Scanning electron microscopy images Raman spectroscopy yielded further overlayer. Both exhibited electrochemical responses Fe(CN) 3 -/4- , Ir(Cl)) -2/-3 Fe +2/+3 comparable typical seen high-quality, thin-film electrodes. behavior assessed pipette electrode housed packed with binder. electrodes more plagued ohmic resistance effects than because reduced contact. Importantly, it found are dimensionally stable during anodic polarization at 1.4 V vs Ag/AgCl (1 h) 0.5 M SO 80°C. In contrast, glassy polarized under identical conditions underwent significant microstructural degradation corrosion.