Preparation and photoelectrochemical characterization of WO 3 /TiO 2 nanotube array electrode

WO 3 /TiO 2 nanotube array electrode was fabricated by incorporating WO 3 with TiO 2 nanotube array via a wet impregnation method using ammonium tungstate as the precursor. TiO 2 and WO 3 /TiO 2 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 WO 3 /TiO 2 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 WO 3 /TiO 2 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 TiO 2 nanotube array electrode. The i ss for glucose oxidation at WO 3 /TiO 2 nanotube array electrode is much higher than that at the pure TiO 2 nanotube array electrode.