▎ 摘　　要

A series of BiFeO3/(N-doped) graphene composites are prepared by a facile hydrothermal method. BiFeO3/N-doped graphene shows photocatalytic performance superior to that of BiFeO3/graphene and pristine BiFeO3. The enhanced photo-degradation performance of BiFeO3/N-doped graphene are mainly attributable to the improved light absorbance of the composite, abundant active adsorption sites and high electrical charge mobility of N-doped graphene, and the downward band bending of BiFeO3 at the composite interface. In particular, X-ray photoelectron spectroscopy analyses reveal that the electron energy band of BiFeO3 is downward bent by 1.0 eV at the interface of BiFeO3/N-doped graphene, because of different work functions of both materials. This downward band bending facilitates the transfer of photogenerated electrons from BiFeO3 to N-doped graphene and prompts the separation of photo-generated electron-hole pairs, leading eventually to the enhanced photocatalytic performance. (C) 2016 Elsevier B.V. All rights reserved.