Mesoporous Single Crystal Rutile TiO2 Rods Modified with Ag Nanoparticles as a Photocatalyst for Degradation of Pollutants

Ag nanoparticles modified mesoporous single crystal rutile TiO2 rods (Ag/MSRT) with different Ag content have been fabricated through a process in combination silica template method with photodeposition. The physicochemical properties of as-prepared Ag/MSRT were characterized in detail by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N-2 adsorption, UV-visible diffuse reflectance spectroscopy and PL fluorescence spectrum. The photocatalytic properties of Ag/MSRT were evaluated through the photodegradation of RhB in aqueous solution. The results showed that Ag nanoparticles were mainly dispersed in the channels of mesoporous TiO2 microrods, and all Ag/MSRT samples exhibited enhanced photocatalytic activities than that of bare MSRT microrods. The degradation ratio of RhB under simulated solar and absolute visible light was increased gradually with the increase of Ag content. However, too much of Ag deposition resulted in large silver particles anchored on the surface of MSRT, and the corresponding photocatalytic performance was dropped. The enhanced activities of Ag/MSRT photocatalysts can be attributed to the unique mesoporous structure of TiO2, the enhanced separation of photo-induced electron holes pairs and promoted visible light absorption by Ag nanoparticles.