Weak-light-driven Ag–TiO2 photocatalyst and bactericide prepared by coprecipitation with effective Ag doping and deposition

TiO2 can mainly absorb ultraviolet light (UV) and thus the strong light irradiation of photocatalyst is highly needed to obtain efficient charge carrier (electrons and holes) production for subsequent reactions. In this paper, Ag–TiO2 nanoparticles with high Ag dispersibility were prepared by different Ag contents (0–6 at. %) and calcination temperatures (200–600 °C) using a coprecipitation method. Results showed that Ag inhibited the transformation of anatase to rutile TiO2, resulting in the decreased Eg and increased amounts of chemisorbed hydroxyl oxygen as well as oxygen vacancy. 2% Ag–TiO2 possessed the best and high photocatalytic efficiency under weak UV and visible light irradiation (15W). The bactericidal activity of Ag–TiO2 nanoparticles was also enhanced compared with pure TiO2, and further enhanced with Ag content. The superior performance was mainly ascribed to the synergistic effect of Ag and TiO2.