Preparation of SiO2-Coated TiO2 Composite Materials with Enhanced Photocatalytic Activity Under UV Light

SiO2-coated TiO2 composite materials with enhanced photocatalytic activity under UV light was prepared by a simple catalytic hydrolysis method. XRD, TEM, UV-vis spectroscopy, Photoluminescence, FT-IR and XP spectra were used to characterize the prepared samples. The obvious shell-core structure was shown for obtained SiO2@TiO2 sample. The average thickness of the SiO2 coating layer was 2-3 nm. The interaction between SiO2 and TiO2 restrained the recombination of excited electrons and holes. The photocatalytic activities were tested in the degradation of an aqueous solution of a reactive dyestuff, methylene blue, under UV light. The photocatalytic activity of SiO2@TiO2 was much higher than that of P25 and mechanical mixing sample SiO2/TiO2. The possible mechanism for the photocatalysis was proposed.