Synthesis of anatase TiO2 in a vinyl-containing ionic liquid and its enhanced photocatalytic activity

TiO 2 microspheres were synthesized by the sol–gel method using the ionic liquid (IL) 1-vinyl-3-propylimidazolium iodide (VPIM + I − ) as a reaction medium, then calcined at 500 °C. The samples were characterized by X-ray diffraction, scanning electron microscopy, and ultraviolet–visible (UV–Vis) diffuse reflectance spectroscopy. The phase of TiO 2 microspheres is anatase, and VPIM + I − is able to favor the growth of anatase phase and prevents the collapse of small pores. The photocatalytic activity of TiO 2 -IL was tested by degradation of 2-nitrophenol under UV light illumination. The photocatalytic activity of TiO 2 -IL was higher than that of samples prepared in the reaction medium without VPIM + I − .