Preperation and Characterization of Monolayered or Two-layered Titania Modified Mesoporous Molecular Sieves MCM-41

Two kinds of titania modified the inner surface of mesoporous slilcate MCM-41 (MCMTiO2 and MCM-Ti-TiO2) were synthesized by precursor tetrabutyltitanate and calcined MCM-41. The samples were characterized by XRD, FTIR, nitrogen adsorption/desorption at 77K and solid state diffuse reflectance UV-vis spectroscopy. XRD suggested that a long-range a long-range order kept in the hexagonal phase of titania modified MCM-41. Tetrabutyltitanate cocondensation with the pendant OH groups of MCM-41 via Si-O-Ti bonds and titania modified the inner walls of MCM-41. Titania on the inner walls of modified MCM-41 was estimated monolayer or two-layer according to the results of nitrogen adsorption/desorption isotherms. In UV-vis spectra, titania modified MCM-41 had significant blue shift compared to bulk TiO2 which is attributed to the well known quantum size effect for semiconductor as the particle size decreases.