Green synthesis of BiOBr modified Bi2O2CO3 nanocomposites with enhanced visible-responsive photocatalytic properties

Abstract

BiOBr/Bi₂O₂CO₃ nanocomposites with mesh-like structures were simply synthesized by a green solid-state chemical reaction route with no extra template or surfactant. The as-synthesized nanocomposites have an altered thickness with the different composite ratio and exhibited excellent visible light photocatalytic activity for the degradation of dyes. The optimum photocatalytic activity of BiOBr/Bi₂O₂CO₃ with a molar percentage of 60% was almost 25 times higher than Bi₂O₂CO₃ towards degradation of RhB by visible-light. The enhanced photocatalytic activity could be attributed to the extended absorption in the visible light range and the formation of p–n heterojunctions between p-type BiOBr and n-type Bi₂O₂CO₃ which promoted the photogenerated electron–hole separation. Radical scavenger experiments indicated that ·O²⁻ and h⁺ played a major role during the RhB degradation process. The photocatalytic mechanism during the degradation process was also proposed.