One-pot Synthesis and Photocatalysis of Encapsulated TiO_2 in Mesoporous SiO_2

摘要

Nano TiO_2 particles encapsulated in mesoporous SiO_2 materials(abbreviated as TiO_2/MS)were prepared by incorporating the nano-sized TiO_2 particles in the pore-directing micelles during the cooperative assembly of silica precursor and surfactant.The materials were characterized with X-ray powder diffraction(XRD),transmission and scanning electron microcopies(TEM and SEM),N_2 sorption,ICP-MS and UV-Vis spectroscopy.XRD patterns showed that titania was in the anatase phase.The results of TEM and N_2 sorption studies confirmed the deposition of nano-sized particles inside the mesopores of silica material without destroying their integrity.UV-Vis spectra showed blue shift of the absorption edge for TiO_2/ MS relative to bulk anatase.When used as photocatalysts,TiO_2/MS showed similar activity as anatase TiO_2 in photo-degradation of phenol.However,lower activity than anatase TiO_2 was observed in photo-degradation of lipase,implying that most of the nano-sized TiO_2 were encapsulated inside the mesopores of silica.