An electrochemical study on the anodic oxygen evolution on oxide film covered titanium

作者:Kong De Sheng*; Wu Ji Xia
来源:Journal of the Electrochemical Society, 2008, 155(1): C32-C40.
DOI:10.1149/1.2799731

摘要

Anodic oxygen evolution reaction on titanium oxide film and its affect on the surface and bulk properties of the film is an important subject in the Ti-based studies and applications. In this work, the behavior of oxygen evolution and some other related electrode processes occurring at anodically grown TiO2 films on titanium were investigated within a relatively wide potential range by electrochemical measurements in 1 M perchloric acid solution. For the formation of the oxide film, three potential regions (two passive regions and the film breakdown region) were selected. The changes both in surface properties (mainly caused by oxygen evolution) and in bulk properties (mainly caused by increased potential) were taken into account for the observed different oxygen evolution behavior. The origin of a cathodic current peak at -0.2 V revealed in cyclic voltammograms was attributed to the reduction of the oxygen atoms adsorbed/absorbed at the oxide film surface, which were generated during anodic oxygen evolution. The flatband potential for the anodically formed titanium oxide films in 1.0 M HClO4 was estimated as -0.2 V. With the semiconducting energy band structure models constructed for the Ti/oxide film/1 M HClO4 electrode system, both the different behavior for anodic oxygen evolution on the titanium oxide films formed at different potentials and the electron transfer processes for the electrochemical reactions observed in this work were further interpreted.