Fabrication of TiO2/Ag2O heterostructure with enhanced photocatalytic and antibacterial activities under visible light irradiation

TiO2/Ag2O heterostructure prepared by a facile in situ precipitation route was used as an effective visible light-driven photocatalyst for degradation of methylene blue (MB) and inactivation of E. coli. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) revealed that Ag2O nanoparticles were well distributed on the surface of TiO2 microspheres. The TiO2/Ag2O composite with optimal mass ratio of TiO2 and Ag2O displayed extremely good photodegradation ability and antibacterial capability under visible light irradiation, which was mainly ascribed to the synergistic effect between Ag2O and TiO2, including highly dispersed smaller Ag2O particles, increased visible light absorption and efficient separation of photo-induced charge carriers. Meanwhile, the roles of the radical species in the photocatalysis process were investigated. Our results showed that the TiO2/Ag2O could be used as a dual functional material in water treatment of removing the organic pollutant and killing the bacterium at the same time. (C) 2016 Elsevier B.V. All rights reserved.