Significant enhancement in the visible light photocatalytic properties of BiFeO3–graphene nanohybrids

Abstract

Graphene-based visible light photocatalysts have been actively pursued in recent years due to the high charge mobility of graphene and hence, the lower recombination rate of electron–hole pairs. BiFeO₃ with a band gap in the visible range is considered a promising candidate as an oxide photocatalyst. In this contribution, BiFeO₃–graphene nanohybrids are fabricated via facile hydrothermal treatments. The morphology and band structure of BiFeO₃ are modulated by graphene. Nanohybrids with BiFeO₃ nanocrystallites of ∼100 nm uniformly decorated on graphene nanosheets are successfully synthesized, which exhibit a band gap of ∼1.78 eV. Chemical bonding between BiFeO₃ and graphene is characterized by XPS analysis. Significant enhancement in the visible light photocatalytic performance is achieved in the BiFeO₃–graphene nanohybrids. The rate for the photo-degradation of Congo Red under visible light is six times that for BiFeO₃ particles, which is attributed to the combined effects of modulated band gap and covalent bonding between BiFeO₃ and graphene.