Introduction of oxygen-containing functional groups onto diamond electrode surfaces by oxygen plasma and anodic polarization

Two simple methods for chemically modifying boron-doped diamond (BDD) films by oxidative treatment were examined. These treatments have shown promise in imparting selectivity to BDD electrodes, for example, between dopamine and ascorbic acid (AA). BDD surfaces were treated either by oxygen plasma or anodic polarization in alkaline solution. The treatments resulted in the incorporation of substantial amounts of oxygen on the surface and also increased the overpotential for AA oxidation. Interestingly, using cathodic polarization, the increase in overpotential was largely negated for the anodically treated surface, whereas it was little affected on the plasma-treated surface. Two different models are proposed to explain this difference in behavior. (C) 1999 The Electrochemical Society. S1099-0062(99)05-079-6. All rights reserved.