α-Fe2O3 modified Bi2WO6 flower-like mesostructures with enhanced photocatalytic performance

alpha-Fe2O3 modified Bi2WO6 mesostructures were facilely prepared by an impregnation method. The characterizations of phase structure, morphology, microstructure, UV-vis absorption, photoluminescence, BET and solar simulated photocatalytic behavior were systematically conducted. The Fe2O3/Bi2WO6 heterostructure with a Fe mass percentage in 0.05-0.2% presented obviously enhanced photocatalytic activity for the degradation of Rhodamine B than pristine Bi2WO6. In particular, the apparent reaction rate constant with Fe-0.1% was 2.24-folds of that of pure Bi2WO6. UV-vis diffuse reflectance spectra showed that the modification of a-Fe2O3 broadened the visible light absorption of Bi2WO6. The decreased photoluminescence indicated an effective suppression of the recombination of electron-hole pairs at Fe2O3/Bi2WO6 interface. The band-gap coupling effect between Fe2O3 and Bi2WO6 was interpreted via comparison of relative valence and conductance potentials, which confirmed an irreversible flow of electrons and holes in the interface of Fe2O3/Bi2WO6. Moreover, the composite showed excellent circulation stability, suggesting potential application in dealing with environmental pollutions. 2013 Published by Elsevier Ltd.