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.