Effects of controlled anodic treatments on electrochemical behaviour of boron doped diamond

The electrochemical behaviour of as-deposited and anodically treated samples is studied by cyclic voltammetry in the presence of redox couple (Ce4+/Ce3+). Two kinds of anodic pre-treatments are performed, playing on the current density and on the duration of the galvanostatic step. Mott-Schottky plots are reported, and related to the energy band diagram evolution of the electrodes after anodic processes. The electrochemical behaviour modification is correlated to the surface wettability evolution and flat band potential shift. For mild anodic pre-treatments, a conservation of the superficial conductive layer (SCL), known to exist on hydrogen-terminated boron doped diamond (BDD), is proposed, while for strong treatments, the SCL disappears. (C) 2006 Elsevier B.V. All rights reserved.