Reactable ionic liquid-assisted solvothermal synthesis of flower-like bismuth oxybromide microspheres with highly visible-light photocatalytic performances

Bismuth oxybromide (BiOBr) flower-like microspheres have been successfully synthesised via a polyethylene glycol 600-assisted solvothermal process in the presence of reactable ionic liquid (IL) 1-hexadecyl-3-methylimidazolium bromide. The morphology and compositional characteristics of BiOBr were investigated by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy and diffuse reflectance spectroscopy. During the reactive process, IL not only acted as a Br source but also as a template for fabrication of BiOBr flower-like microspheres. Photocatalytic activities of flower-like microspheres were evaluated by degradation of rhodamine B under visible-light irradiation. Compared with the BiOBr nanoplates, BiOBr hollow microspheres and TiO₂ (Degussa, P25), BiOBr flower-like microspheres exhibited excellent performance in visible-light-driven photocatalysis.