Abstract: Covalent bonded PW11/TiO2 mesoporous hybrid materials were prepared by grafting a lacunary tungstophosphate PW11 with Keggin structure onto the surface of mesoporous TiO2 that was synthesized using evaporation-induced self-assembly(EISA) method. The structure, PW11 loading and the mechanism for grafting were characterized and studied by means of IR, N2 adsorption-desorption, XRD, TEM and ICP-AES techniques. The photocatalytic activities of the hybrid samples for methyl orange degradation were also investigated. It was shown that as-prepared TiO2 via EISA method before calcinations had an incompact framework. It can partially hydrolyze and react with PW11 to form PW11Ti species, which could condense with TiO2 framework to lead to covalent linkage of PW11 on TiO2. Compared with pure TiO2 support, the crystallinity of anatase was lowered slightly, the pore size and the pore volume decreased in the hybrid samples. However, the activities for methyl orange degradation increased significantly, which can be attributed to the synergistic effect between polyoxometalate and TiO2.

Key words: TiO2, Polyoxometalate, Grafting, Mesoporous hybrid materials, Photocatalysis