Preparation and Visible Light Photoelectrochemical Response of TiO<sub>2</sub>-MoO<sub>3</sub> Composite Nanotube Thin Films

Abstract

TiO2-MoO3 composite nanotube thin films were obtained by the thermal treatment of titanium dioxide nanotube thin films in the presence of MoO3. Titanium dioxide nanotubes (TiO2 NTs) thin films were prepared by the anodic oxidation of titanium foil. The resultant thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), Mott-Schottky analysis, and photoelectrochemical methods. The XRD patterns showed that an anatase type TiO2 was present in the thin films. Nanotube structures for the thin films were observed by SEM. MoO3 was dispersed on the TiO2 NT top surface. Elemental analysis by XPS showed that MoO3 recombined with the TiO2 NTs to form TiO2-MoO3 composite nanotube thin films. The influence of time and temperature of thermal treatment on the photoelectrochemical response for the TiO2-MoO3 composite nanotube thin film electrodes were investigated. The photoelectrochemical response of the TiO2-MoO3 composite nanotube thin film increased under visible light illumination compared with the pristine TiO2 NTs. The highest photoelectrochemical response was observed for the TiO2-MoO3 composite nanotube thin film obtained by thermal treatment at 450 °C for 60 min.