Large-scale preparation of rice-husk-derived mesoporous SiO2@TiO2 as efficient and promising photocatalysts for organic contaminants degradation

Abstract Mesoporous SiO 2 @TiO 2 photocatalysts with application prospect for organic contaminants degradation were prepared by utilizing rice husk (RH), an easy-available bioresource, as the biotemplate. Structures and physicochemical properties of RH-derived SiO 2 @TiO 2 photocatalysts were systematically characterized and discussed. Results indicate the RH-derived mesoporous and thermal-stable template, which can postpone the anatase-rutile phase transition of TiO 2 at high temperatures, is mainly consisted of tightly compacted amorphous SiO 2 nanoparticles. Optimized calcination temperature of 700 °C is positive for preparing the most active RH-derived SiO 2 @TiO 2 , which has the anatase phase, mesoporous structure, proper crystalline degree (grain size of 22.75 nm), specific surface area of 41.13 m 2 /g, and high ability in separating the photogenerated electron-hole pairs, for removal of Rhodamine B (RhB) in aqueous solutions under both the xenon lamp and visible light irradiation. Moreover, large-scale preparation, stable, and recyclable properties of the photocatalysts are also confirmed, which makes them as promising photocatalysts for practical application.