Preventing Photoelectrochemical Corrosion of ZnO by Ti Inclusions

抄録

Zinc oxide films containing small amounts of Ti oxide were prepared by heat treatment of Ti sheets with a Zn plated overlayer. Long term photoelectrochemical corrosion tests of the film at a constant potential of 1 V vs. Ag | AgCl was carried out. It was found that Zn²⁺ ions initially dissolved into the electrolyte solution but that dissolution then stopped. This behavior can be explained by an increase in the surface concentration of Ti. After some dissolution of Zn, the increased Ti concentration enables the surface to withstand further photoelectrochemical corrosion. This Ti containing oxide film showed a much better photoresponse than that of Ti oxide alone in the long wavelength region and would be a good candidate for photo anodes in aqueous electrolytes.