Titanium dioxide/electrolyte solution interface: Electron transfer phenomena

Electron transfer between a titanium dioxide/electrolyte solution interface has been studied. As found by other researchers of similar interfaces (TiO 2- and ZnO-electrolyte solution), a slow consumption of OH- ions takes plac e in this type of interface. A theoretical model has been developed for cal culating the change in the Fermi energy of both electrolyte solution and se miconductor, showing that ion consumption from the solution is favoured by the decrease of the difference between their Fermi energies. A kinetic cons tant (rt) is found to characterise the consumption process, its value incre asing 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. (C) 2000 Academic Press.