Preparation and Characterization of Antimony-Doped Tin Dioxide Electrodes. Part 1. Electrochemical Characterization

Abstract

Antimony and antimony−platinum doped tin dioxide electrodes supported on titanium have been prepared by thermal decomposition. Ti/SnO2−Sb electrodes have a cracked-mud structure, typical of oxide electrodes prepared by thermal decomposition. The introduction of platinum in the oxide layer has a packing effect in the coating morphology. The electrochemical characterization of these electrodes has been performed in acid medium, and a relation between the roughness factor (measured from electrode capacitance) and electrochemical porosity (related to the voltammetric charge) has been established. The mechanism for the oxygen evolution reaction has been determined by Tafel measurements indicating that the electrodes prepared are nonactive electrodes. The electrocatalytic activity strongly depends on geometric factors, since the activity toward oxygen evolution increases with the electrochemical porosity. Anodic stability of Ti/SnO2 electrodes has been checked with accelerated service life tests. The introduction of platinum in the oxide coating increases the service life by 2 orders of magnitude.