Facile microwave-assisted ionic liquid synthesis of sphere-like BiOBr hollow and porous nanostructures with enhanced photocatalytic performance

Abstract

In this work, two kinds of self-assembled hierarchical BiOBr microcrystals were rapidly synthesized through a simple microwave-assisted route in the presence of reactable ionic liquid 1-hexadecyl-3-methylimidazolium bromide ([C16mim]Br). These porous and hollow BiOBr microspheres were obtained via a facile solvothermal method with or without polyvinyl pyrrolidone (PVP), respectively. During the synthetic process, ionic liquid [C16mim]Br played as solvent, reactant and template at the same time. Moreover, the BiOBr hollow and porous microspheres exhibited outstanding photocatalytic activities for the degradation of rhodamine B (RhB) under visible light irradiation. A possible photocatalytic mechanism was also discussed in detail. It can be assumed that the higher photocatalytic activities of BiOBr porous microspheres materials could be ascribed to the novel structure, larger specific surface area, narrower band gap structure and smaller particle size. Keywords: BiOBr, Photocatalytic, Ionic liquid, Microwave