Ionic liquid-templated synthesis of mesoporous CeO2–TiO2 nanoparticles and their enhanced photocatalytic activities under UV or visible light

Mesostructrured CeO2–TiO2 nanoparticles with different CeO2 contents have been successfully synthesized using ionic liquid (1-hexadecane-3-methylimidazolium bromide, C16MIM+Br−) as a template by a hydrothermal method. The prepared materials were characterized by means of X-ray diffraction (XRD), nitrogen adsorption–desorption, transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectra analysis. The obtained CeO2–TiO2 materials exhibit large specific surface area and uniform pore sizes. Introduction of CeO2 species can effectively extend the spectral response from UV to visible area and enhance the surface hydroxyl groups of the mesoporous TiO2. The CeO2–TiO2 nanocomposites show high photocatalytic activity in the degradation of the p-chlorophenol aqueous solution under the UV or visible irradiation.