▎ 摘　　要

The graphene-bismuth ferrite (Graphene-BiFeO3) hybrids with different graphene contents were synthesized by a hydrothermal method. Their structure was characterized by XRD, SEM and FTIR. Their light reflection and absorption were investigated by UV-visible diffuse reflectance spectroscopy and photoluminescence spectroscopy, respectively. Their photocatalytic properties were evaluated by degrading methylene blue (MB) and rhodamine B (RhB) dyes under irradiation with tungsten light. Results showed that the hybrids had a sphere-like morphology, within which the graphene was uniformly dispersed between the BiFeO3 spheres. The hybrids had lower band gaps and higher absorption intensities in the visible light region (400-800 nm) than pure BiFeO3, and achieved much higher degradation rates for both MB and RhB. The hybrid with a graphene content of 3.0 wt% exhibited the best photocatalytic performance, and its degradation rate constants for MB and RhB reached to 0.083 and 0.10, respectively, which are about 10 times higher than pure BiFeO3. The introduction of the graphene effectively inhibited the recombination rate of the excited electrons and the holes in BiFeO3. Their magnetism made them easy to recover from the dye solutions and their photocatalytic activities remained unchanged after recycling 5 times.