Correlation between flat-band potential position and oxygenated termination nature on boron-doped diamond electrodes

摘要

This paper deals with a study about the position of the flat-band potential and the surface chemistry of boron-doped diamond electrodes. Successive and mild anodic treatments have been performed on as-deposited electrodes, in H2SO4. From Mott— Schottky plots, flat-band potential (V_(FB)) evolution has been monitored, exhibiting successively negative then positive shifts during surface oxidation, depending on the anodic coulometric charge. Thanks to surface characterization by X-ray Photoelectron Spectroscopy (XPS), this particular evolution of V_(FB) has been related to the evolution of specific oxygen functionalities at the surface. While the general trends in the literature is to associate the V_(FB) displacement with the generation of oxygenated terminations, the results presented in this study exhibit the high sensitivity of V_(FB) to hydroxy 1 or ether groups.