A simple, facile and low-cost method for the preparation of mixed-phase titanium oxide: toward efficient photoelectrochemical water oxidation

Abstract

A new, low-cost and facile method for the preparation of a titanium oxide photocatalyst on a titanium electrode through simple high-voltage anodization, using different applied bias potentials in an alkaline solution, is reported. The photoelectrochemical properties of the prepared photocatalysts are studied and compared to those of titanium nanotubes prepared by an anodization method in fluoride ion-containing acidic solutions. Our photocatalyst under the optimized conditions exhibited better photoelectrochemical performance than titanium nanotubes. The anodization potentials and calcination steps have a significant influence on the photoelectrochemical properties of the photocatalysts. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, UV-Vis diffuse reflectance spectroscopy, X-ray diffraction, attenuated total reflectance spectroscopy, and Raman spectroscopy were exploited to characterize the photocatalyst prepared under the optimum conditions. The experiments showed that the photocatalyst is a mixed-phase titanium oxide, containing both anatase and rutile phases, with vacant oxygen sites, all of which can be considered as justifications for the better photoelectrochemical performance over titanium nanotubes.