Correspondence between Experiment and Theory of Bulk Electrocrystallisation at Solid Electrodes in Aqueous Electrolyte

A model of electrodeposition and electrodissolution at electrode surfaces in aqueous solution is presented. The description is based on the assumption that redox reaction of water is the more important process controlling the electrode kinetics. Chronoamperometric measurements and experiments of cyclic voltammetry indicate that the current fundamentally is proportional to inverse time. It was proposed that redox-active species different from water never touch the surface but they predominantly interact with surface-active hydrogen or oxygen formed at the surface by redox processes of water. An excellent correspondence was found between the number of ideal-gas molecules in a monolayer at the electrode surface and the charge required, as to dissolve one monolayer of electrodeposited metal. The linear relation between standard enthalphy of metal-oxide formation and standard-reduction potential shows that metal oxide formation at the electrode corresponds to oxidation of a metal in an atmosphere of oxygen.