Boron-doped diamond (BDD) electrodes are being increasingly investigated for application to electrochemical CO2 reduction. Previous, studies have mainly focused on microcrystalline (MC) BDD electrodes. In our study, we present an analysis of electrochemical CO2 reduction using sub-microcrystalline (SMC) BDD electrodes with different boron doping concentrations (0.28%, 0.11% and 0.03%). Unlike the microcrystalline case, these synthetic SMC BDD films with high sp2-bonded carbon do not show a boron-concentration dependence in terms of the activity of CO2 reduction to form formic acid (HCOOH). All the electrodes enabled efficient CO2 reduction at close to the maximum Faradaic efficiency for HCOOH in the range of 70% to 80%. From our observations, it is suggested that the sp2-bonded carbon should be crucial for the CO2 reduction. The results are hoped to enable a relaxation on the restrictions on the use of BDD electrodes towards industrial CO2 reduction application.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Mechanical Engineering
- Materials Chemistry
- Electrical and Electronic Engineering