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

Highlights: • TiO₂/Ag₂O composite photocatalyst was synthesized successfully. • The composites show better photocatalytic activity for MB under visible light. • The composites also possess good antibacterial properties. • The mechanism of enhanced photocatalytic activities was investigated. - Abstract: 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 TiO_2, 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.