Electrochemical behavior of Au nanoparticle deposited on as-grown and O-terminated diamond electrodes for oxygen reduction in alkaline solution

An nanoparticle was electrochemically deposited on both as grown and oxygen-terminated (O-terminated) boron-doped diamond (BDD) films. The surface coverages of Au nanoparticle were 0.07 and 0.18 corresponding to the areas of An 0.012 and 0.029 cm(2), respectively, as noted from linear sweep voltammetry. The SEM studies indicated different morphologies of Au deposition such as random distribution of small spherical particles at both the grain boundaries and the facets on the as grown diamond film and clusters principally on the cross edges of two facets on the O-terminated diamond. The electrochemical behavior for oxygen reduction was examined using differential pulse voltammetry (DPV), which confirmed the higher catalytic efficiencies of Au deposited as grown and O-terminated BDD electrodes when compared to a polycrystalline An electrode. Moreover, the mechanism of Au nanoparticle deposited BDD films for the oxygen reduction was investigated by ac impedance and hydrodynamic voltammetric methods. (C) 2004 Elsevier Ltd. All rights reserved.