Intergrowth and coexistence effects of TiO2-SnO2 nanocomposite with excellent photocatalytic activity

The TiO2-SnO2 nanocomposite with excellent photocatalytic activity was synthesized via sol-hydrothermal process. The obtained samples were characterized by XRD, FETEM, LRS and UV-vis DRS. The photocatalytic activities of as-prepared samples were investigated by degradation of methyl blue (MB) under UV illumination. The results clearly indicate that a small quantity of SnO2 adding can accelerate the anatase-to-rutile transformation greatly, and the nanocomposites consisting of anatase (A) and rutile (R) phases are formed in the molar ratios Ti:Sn = 20:1, 60:1 and 80:1, respectively. They show the higher photocatalytic activity than that of TiO2 (A). Remarkably, they can be enhanced up to several times compared with TiO2-P25. Especially, the catalyst of molar ratio Ti:Sn = 60:1 is found to be the most efficient, it exhibits a complete decomposition of MB within 20 min under UV irradiation. The results are explained by taking into account the intergrowth and coexistence effects of optimized anatase-rutile phases TiO2-SnO2 catalyst, the larger specific surface area and Quantum-sized TiO2-SnO2 particles obtained from the sol-hydrothermal method. (C) 2014 Elsevier B.V. All rights reserved.