Small amount of TiO 2 modified SnO 2 with enhanced photocatalytic performance toward the removal of rhodamine B

Abstract

Tin dioxide (SnO2) photocatalyst has broad prospects for the degradation of toxic organic pollutants; however, its practical application is greatly hampered by poor activity due to the high recombination rates of photogenerated electron-hole pairs. In this work, titania (TiO2) modified SnO2 photocatalysts were obtained by a facile hydrothermal method to suppress the rapid recombination of photogenerated electron-hole pairs and improve the photocatalytic activity. Ultraviolet–visible (UV–vis)_ diffuse reflectance spectra suggest that TiO2–SnO2 composite photocatalysts hold stronger UV light absorption ability than that of the pure SnO2. Surface photovoltage spectroscopy and photoelectrochemistry results show that the separation rate of photogenerated charge pairs of TiO2–SnO2 photocatalysts was greatly enhanced. The photocatalytic activities of the photocatalysts were evaluated by the decay of rhodamine B (RhB) under UV irradiation illumination. The results display that modification of SnO2 by TiO2 can largely enhance the photocatalytic activity and the photocatalytic performance of 0.5:1-TS sample is nearly 5 times that of the pure SnO2. Moreover, maintaining the ratio of TiO2 and SnO2 at 0.5:1, the amount of catalyst was 30 mg, the concentration of dye was 10 mg/l, and the pH of RhB solution was 2, the sample has the best photocatalytic activity.