The effect of heat treatment on the anatase–rutile phase transformation and photocatalytic activity of Sn-doped TiO(2) nanomaterials

Sn-doped TiO(2) nanomaterials with different amounts of Sn (1, 2.5, 5, 10, and 15 at%) were prepared by a sol–gel method and characterized by XRD, TG, DTA, EDS, XPS, DRS, SEM, BET, and PL. The photocatalytic activity of the prepared samples was investigated by measuring the degradation of rhodamine B in aqueous solution under UV light. The experimental results indicate that doping with Sn promotes phase transformation from anatase to rutile. The photocatalytic activity of TiO(2) is influenced by both the heat treatment temperature and the Sn doping concentration. 1% Sn–TiO(2) exhibits the highest degradation rate at 350 °C and 5% Sn–TiO(2) exhibits the best photocatalytic activity at 500 °C and 650 °C. The enhancement of the photocatalytic activity can be ascribed to a larger surface area and a better hydration ability, as well as less recombination of the photogenerated pairs.