Advanced visible light photocatalytic properties of BiOCl micro/nanospheres synthesized via reactable ionic liquids

BiOCl uniform flower-like microspheres and porous nanospheres structures have been successfully synthesized through a one-pot ethylene glycol (EG)-assisted solvothermal process in the presence of reactable ionic liquid 1-hexadecy-3-methylimidazolium chloride ([C(16)mim]Cl) and [C(16)mim]Cl-PVP composite system. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and UV-vis diffuse reflectance spectroscopy (DRS). During the reaction process, the ionic liquid acted not only as the solvent and the template, but also as a Cl source for the fabrication of BiOCl microspheres. The effect of the cation alkyl chain length of ionic liquids on morphology and optical absorption properties was investigated and is discussed in detail. In addition, the photocatalytic activity of the BiOCl samples was evaluated by rhodamine B (RhB) dye degradation under visible-light irradiation. It was found that BiOCl porous nanospheres exhibited higher photocatalytic activity than that of the samples prepared with conventional method and TiO2 (Degussa, P25). (C) 2012 Elsevier Ltd. All rights reserved.