Preparation of BiFeO3 -graphene nanocomposites and their enhanced photocatalytic activities

Abstract

BiFeO3 nanoparticles were prepared via a polyacrylamide gel route. BiFeO3-graphene nanocomposites were fabricated by mixing BiFeO3 nanoparticles and graphene into absolute ethanol solution followed by thermal drying. The TEM observation demonstrates that the BiFeO 3 nanoparticles are well anchored onto graphene sheets. The photocatalytic activities of the as-prepared samples were evaluated by the degradation of methyl orange (MO) under simulated sunlight irradiation. Compared to bare BiFeO3 nanoparticles, BiFeO3-graphene nanocomposites exhibit enhanced photocatalytic activity. The outstanding photocatalytic performance is mainly ascribed to the efficient transfer of photogenerated electrons from BiFeO3 to graphene, thus leading to an increased availability of h+ for the photocatalytic reaction. In addition, hydroxyl (·OH) radicals were detected by the photoluminescence technique using terephthalic acid as a probe molecule and are found to be produced on the irradiated BiFeO3 and BiFeO3-graphene nanocomposites; in particular, an enhanced yield is observed for the latter. © 2013 J. F. Dai et al.