Increasing the Electric Double‐Layer Capacitance in Boron‐Doped Diamond Electrodes

Abstract Highly boron‐doped diamond (BDD) electrodes containing sp 2 carbon impurities exhibit an increase in the electric double‐layer capacitance ( C dl ) after anodic oxidation. Although it is known that the electrochemical properties of BDD electrodes are affected by several factors, including the boron concentration, the amount of sp 2 carbon impurity, and the surface termination and orientation, clarification of the mechanism for the increase in C dl needs to be done. To this end, we prepared several BDD samples under various conditions and the properties of these samples, including C dl , were systematically investigated. The mechanism for the increase in C dl in particular, including the effect of the surface termination, is discussed.