The dependence of the surface diffusion coefficients of gold atoms on the potential: its influence on reconstruction of metal lattices

Abstract

By using a method based on the time dependence of the surface roughness factor of electrodispersed gold electrodes it was possible to estimate values of the surface diffusion coefficients (Ds) of gold atoms in contact with an 1M HClO4 electrolytic solution at room temperature and as a function of the potential. The exponential growth of Ds with E at potentials positive with respect to the zero charge potential (Ez), is interpreted as a consequence of the increase in the surface mobility of gold atoms, associated with their growing interactions with species in the electrolyte (water molecules), and the consequent decrease of their interactions with bulk gold atoms, i.e. with the loss in metallic character inherent in the use of individual orbitais in the formation of covalent bonds with hydroxyls arising from water molecules.