Characterization and evaluation of the photocatalytic properties of wormhole-like mesoporous silica incorporating TiO2, prepared using different hydrothermal and calcination temperatures

Abstract

TiO2–SiO2 mesoporous materials were synthesised by deposition of TiO2 nanoparticles prepared by the sol–gel method on to the internal pore surface of wormhole-like mesoporous silica. In this work we synthesised wormhole-like mesoporous silica of different surface area by changing the hydrothermal temperature (70, 100, or 130 °C). Subsequent to this, titania solution was deposited on to the inner surface of the pores and this was followed by calcination at different temperatures (400, 600, or 800 °C). The effect of different hydrothermal and calcination temperature on the photocatalytic properties was evaluated. The samples were characterized by N2-sorption, X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, and transmission electron microscopy. The effect of different hydrothermal and calcination temperatures on the photocatalytic properties was evaluated by measuring the degradation of methylene blue in aqueous solution under UV light irradiation (mercury lamp, 125 W). The results indicated that appropriate surface area and degree of crystallinity are two important factors for obtaining high photocatalytic efficiency. Samples prepared at a hydrothermal temperature of 100 °C and calcined at 800 °C had the best photocatalytic performance, because of the highest surface area and high crystallinity.