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.