Ionic liquid assisted synthesis and photocatalytic properties of α-Fe2O3 hollow microspheres.

α-Fe2O3 hollow microspheres have been successfully prepared in the presence of metal ion-containing reactable ionic liquid 1-octyl-3-methylimidazolium tetrachlorideferrate(III) ([Omim]FeCl4) under the solvothermal condition. The as-prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), FT-IR spectrum, and diffuse reflectance spectroscopy (DRS). The effect of concentration of ionic liquids on the morphology of α-Fe2O3 had been investigated in detail. It was found that [Omim]FeCl4 acted not only as Fe source but also as solvent and template for the fabrication of α-Fe2O3 hollow microspheres. In addition, the electrochemical and photocatalytic properties of α-Fe2O3 were investigated. The α-Fe2O3 hollow microspheres exhibited high conductivity, high photocurrent, and high photocatalytic activity. The designed hollow microsphere showed potential applications in photocatalysis.