The role of water activity in the competition between anodic decomposition and stabilization of the GaP/Fe 2+ electrode

Abstract

By rotating ring-disk experiments, the competition was studied between the anodic decomposition of the GaP electrode and the stabilization of this electrode by ferrous ions in aqueous electrolytes with and without 4 M LiCl added. From the results, it follows that a different competition mechanism is operating in the two media, leading to a substantial improvement of the stabilization in the presence of 4 M LiCl. These effects are attributed to the decreased water activity in the 4 M LiCl solution, causing a shift in the equilibrium of a surface chemical reaction step of the multi-equivalent anodic decomposition reaction.