Silver nanoparticles decorated titanium dioxide-tungsten trioxide nanotube films with enhanced visible light photo catalytic activity

A simple strategy for synthesizing silver-loaded titanium dioxide-tungsten trioxide nanotubes film for use as recyclable photo catalyst is introduced. Highly ordered and uniformly distributed titanium dioxide-tungsten trioxide nanotubes (WTNTs) on pure titanium were successfully fabricated by one-step electrochemical anodizing and silver deposited on these nanotubes by simple electrochemical method. The as-prepared samples were characterized by X-ray diffraction, field-emission scanning electron microscopy, ultraviolet-visible diffuse reflectance spectroscopy and energy dispersive X-ray spectrometer methods. The degradation of methylene blue (MB) was used as a model reaction to evaluate the photo catalytic activity of the obtained samples. Compared with the pure TiO2 nanotubes (TNTs) and bare WTNTs, the WTNTs decorated with silver (Ag/WTNTs) showed much higher photo catalytic activity in the degradation of MB under visible light irradiation. Under the same condition, no obvious photo degradation of methylene blue was found for pure TiO2 nanotubes. The average photo catalytic degradation efficiency of the Ag/NTNTs obtained for the degradation of MB is 2.3 times higher than those of bare NTNTs. After 6 successive cycles under 720 min visible light irradiation, Ag/WTNTs remained highly stable photo catalytic activity. The enhanced photo catalytic activity of ternary Ag/WTNTs photo catalyst was ascribed to improved light absorption, reduced carrier recombination and surface plasmon resonance of Ag nanoparticles. Moreover, the excellent stability and reliability of the Ag/WTNTs photo catalyst demonstrated a promising application for organic pollutant removal from water under visible light irradiation.