Improvement of TiO2 photocatalytic properties under visible light by WO3/TiO2 and MoO3/TiO2 composites

The WO3/TiO2 or MoO3/TiO2 composites with different compositions have been prepared by a facile sol-gel method. The obtained composites were characterized using X-ray diffraction (XRD), BET surface area analysis, electron dispersion spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) emission spectrum. The research results show that BET specific surface areas of the composites are significantly enhanced and the composites possess higher photocatalytic activity than pure TiO2 for the degradation of Rhodamine B (RhB) under visible light irradiation. It has been demonstrated that the photocatalytic activity depends on the composition and calcination temperature of composites, and degradation conditions for RhB. The improvement of photocatalytic activity can be attributed to the reduction of the electron-hole recombination rate due to the formation of WO3/TiO2 or MoO3/TiO2 heterostructures, which have been confirmed by XPS and PL spectra. (C) 2015 Published by Elsevier B.V.