Photoelectrochemical Properties of the Sol-Gel Derived Ti_1-xV_xO₂ Thin Film Electrodes

Abstract

The origin of the photoresponse in the visible region observed for the sol-gel derived Ti_1-xV_xO₂ thin films has been studied in relation to the doping level, x, which is ranging from 0.03 to 0.12. Effects of the postheating atmosphere and the substrate nature on the crystallization behavior and photoelectrochemical properties of the films were examined. X-ray diffraction analysis revealed that thin films with x≤0.06 consisted only of anatase type TiO₂ phase regardless of the post-heating atmosphere and substrate nature, whereas for the samples with x≥0.07, VO₂ or V₂O₃ phases have been detected in addition to anatase phase depending on the post-heating atmosphere. Differences in photoelectrochemical characteristics between the thin film electrodes with x≤0.06 and x≥0.07 and the origin of the visible photoresponse are discussed on the basis of the difference in crystallization behavior of the Ti_1-xV_xO₂ electrodes.