Influence of Formation and Dissolution Environment on Dissolution Kinetics of Anodic Oxide Films on Antimony

Abstract

Abstract The currentless dissolution behavior of the anodic oxide films formed on antimony in 0.1N H3PO4 was studied as a function of formation voltages and formation current densities. The dissolution rate of the oxide film was examined as a function of the electrolyte composition of the formation medium. Kinetics curves for the dissolution of the oxide film in most media show a two stage process that seems to be related to the dual nature of the oxide film. The validity of the first order mechanism for the dissolution process is illustrated with the kinetics curves of dissolution following the equation: This equation is used for each of the two stages of the dissolution process, with two different values of K. The rate of the dissolution process was found to be a function of electrolyte composition of the formation medium, while no effect was observed for the initial current density of the oxide formation. The role of anion type on the dissolution rate was more pronounced in acidic solutions than in neutral ones.