Preparation and photoelectrochemical characterization of WO3/TiO2 nanotube array electrode

WO3/TiO2 nanotube array electrode was fabricated by incorporating WO3 with TiO2 nanotube array via a wet impregnation method using ammonium tungstate as the precursor. TiO2 and WO3/TiO2 nanotube arrays were characterized by field emission scanning electron microscopy, X-ray diffraction, and energy dispersive X-ray analysis. In order to characterize the photoelectrochemical properties of WO3/TiO2 electrode, electrochemical impedance spectroscopy, and steady-state photocurrent (i(ss)) measurement at a controlled potential were performed in the supporting electrolyte containing different concentrations of glucose. The photoelectrochemical characterization results reveal that WO3/TiO2 nanotube array electrode possesses a much higher separation efficiency of the photogenerated electron-hole pairs and could generate more photoholes on the electrode surface compared with the pure TiO2 nanotube array electrode. The i(ss) for glucose oxidation at WO3/TiO2 nanotube array electrode is much higher than that at the pure TiO2 nanotube array electrode.