Synthesis of thermally stable mesoporous TiO2 and investigation of its photocatalytic activity

The effects of heat treatment, dopant type and thickness of sol layer, on the formation and stability of ordered TiO2 mesostructure were investigated. Higher ageing temperature facilitates the separation of organic phase and inorganic phase, while thinner sol layer facilitates the formation of homogeneous system and improves the mesostructural order of TiO2. Lanthanurn dopant, which is more electropositive than Ti, can improve the thermal stability of mesostructure by enhancing the strength of Ti-O bond. On the contrary, Fe and Pd dopants, which are more electronegative than Ti, decrease the thermal stability of mesostructure. Furthermore, La doped mesoporous TiO2 shows high activity in the photocatalytic degradation of Rhodamine B under the irradiation of visible light. (C) 2007 Elsevier Inc. All rights reserved.