Photocatalytic activity under weak visible light of Fe3+ doped mesoporous CeO2

Mesoporous CeO2 and Ce−Fe−O solid solutions with high content of hydroxyl groups were successfully synthesized using triblock copolymer P123 as the template and Ce(NO3)3·6H2O and Fe(NO3)3·9H2O as raw materials. The resultant samples were characterized by X-ray diffraction (XRD), N2 adsorption−desorption, Raman, UV−vis, transmission electron microscopy, and Fourier transform infrared spectroscopy techniques. The X-ray diffraction results indicated that the synthesized samples exhibited cubic CeO2 without impurities. The photocatalytic activities of the prepared samples were evaluated by the decomposition of Rhodamine B (RhB) dye under weak natural light irradiation. The results showed that the photocatalytic efficiency of mesoporous CeO2 is higher than that of bulk CeO2, but lower than that of mesoporous Ce−Fe−O solid solution. Moreover, removing the template by extraction in ethanol leads to a much better photocatalyst compared with a calcinated one, due to the preservation of the hydroxyl groups on the mesoporous surface.