Highly conductive hydrogenated amorphous carbon with higher resistance to electrochemically induced corrosion was successfully synthesized by incorporating boron atoms and regulating the amount of sp2-bonded carbon with plasma-enhanced CVD method. The structure, electrical properties, and electrochemical reactivity of boron-doped amorphous carbon (B-doped DLC) were investigated. Boron atoms in amorphous carbon acted as an accepter because the conduction of B-doped DLC was p-type. Volume resistivity was 6.36 × 10-2 ω cm at highly B-doped DLC (B = 1.3 atom%). The highly B-doped DLC films exhibited a wide working potential range over 3 V in an aqueous solution. The kinetics of hydrogen evolution, which determines the working potential range, could be suppressed by decreasing the number of boron atoms incorporated in DLC because B atoms act as an electrochemical catalyst for H2 evolution. A double-layer capacitance of the highly B-doped films was as low as boron-doped diamond. This is due to the absence of ionizable surface functionalities like -NH3 and reversible electron transfer kinetics for inorganic redox analytes (Fe(CN)63-/4- and Ru(NH3)62+/3+), which were on the same level as those of boron-doped diamond. The lower kinetics of O2 evolution at B-doped DLC enables to observe the redox reaction of Ce3+/4+ with a standard potential higher than that of H2O/O2. Mn 2+ ions with a standard potential lower than that of H2 evolution could also be electrochemically analyzed in the range from 20 μM to 2.5 mMat moderately B-doped DLC with lower kinetics of H2 evolution.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry