Fabrication of uniformly dispersed Ag nanoparticles loaded TiO2 nanotube arrays for enhancing photoelectrochemical and photocatalytic performances under visible light irradiation

Uniformly dispersed Ag nanoparticles (NPs) were successfully loaded on both the outer and inner surface of the TiO2 nanotube arrays (NTs) through a simple polyol method. The as-prepared Ag/TiO2-NTs were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and UV–vis diffusion reflectance spectroscopy. Photoelectrochemical behaviors were investigated via photocurrent response and electrochemical impedance spectroscopy (EIS). Photocatalytic activity of Ag/TiO2-NTs was evaluated by degradation of acid orange II under visible light irradiation. The results showed that photocatalytic efficiency of Ag/TiO2-NTs is more than 5 times higher than that of pure TiO2 NTs. Comparing with the electrochemical deposition method, the photocatalytic activity of Ag/TiO2-NTs prepared by polyol method has been obviously increased.