Oxide/Electrolyte interface: Electron transfer phenomena

Abstract

Electron transfer on a titanium dioxide / electrolyte solution interface has been studied. As observed by other researchers on similar interfaces (TiO 2 - and ZnO- electrolyte solution), slow consumption of OH - ions was found. A theoretical model has been developed for calculating the change in Fermi energy levels of both electrolyte solution and semiconductor, showing that ion consumption from the solution is favoured by a decreased difference in their Fermi energies. A kinetic constant (υ) is found to characterise the consumption process, its value increasing with electrolyte and semiconductor mass concentrations. Furthermore, this process may be used to estimate the point of zero charge of a titanium dioxide colloidal dispersion.