The effect of nondiamond carbon admixture on the electrochemical behavior of polycrystalline CVD-diamond films

The effect of nondiamond (sp2-) carbon admixture on the surface of polycrystalline boron-doped CVD-diamond electrodes on their electrochemical behavior was studied by comparing the films grown under similar conditions, yet of different thickness. It is shown that with the decreasing of the film thickness (hence, with the increasing of the nondiamond carbon content therein) its surface acquired electrochemical activity: the transfer coefficients of reactions in the [Fe(CN)6]3−/4− redox system increased, the oxygen anodic evolution overvoltage decreased, the differential capacitance increased; on the whole, the diamond electrode demonstrated increasingly better pronounced metal-like behavior.