Preparation of SiO 2-coated TiO 2 composite materials with enhanced photocatalytic activity under UV light

Abstract

SiO 2-coated TiO 2 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 SiO 2@TiO 2 sample. The average thickness of the SiO 2 coating layer was 2-3 nm. The interaction between SiO 2 and TiO 2 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 SiO 2@TiO 2 was much higher than that of P25 and mechanical mixing sample SiO 2/TiO 2. The possible mechanism for the photocatalysis was proposed.