Doping level influence on chemical surface of diamond electrodes

The modification of surface bond termination promoted by the doping level on diamond electrodes is analyzed. The films were prepared by hot filament chemical vapor deposition technique using the standard mixture of H-2/CH4 with an extra H-2 flux passing through a bubbler containing different concentrations of B2O3 dissolved in methanol. Diamond morphology and quality were characterized by scanning electron microscopy and Raman scattering spectroscopy techniques while the changes in film surfaces were analyzed by contact angle, cyclic voltammetry and synchrotron X-ray photoelectron spectroscopy (XPS). The boron-doped diamond (BDD) films hydrophobicity, reversibility, and work potential window characteristics were related to their physical properties and chemical surface, as a function of the doping level. From the Mott-Schottky plots (MSP) and XPS analyzes, for the lightly (10(18) cm(-3)) and highly (10(20) cm(-3)) BDD films, the relationship between the BDD electrochemical responses and their surface bond terminations is discussed. (C) 2012 Elsevier Ltd. All rights reserved.