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 (iss) 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 iss for glucose oxidation at WO3/TiO2 nanotube array electrode is much higher than that at the pure TiO2 nanotube array electrode.