Rice-straw-derived hybrid TiO₂-SiO₂ structures with enhanced photocatalytic properties for removal of hazardous dye in aqueous solutions

Rice straw, an agricultural bioresource, is utilized as a biotemplate in order to synthesize a hybrid TiO₂-SiO₂ structure, and the resulting products were used for removing hazardous methylene blue dye from aqueous solutions. Samples of the as-prepared hybrid TiO₂-SiO₂ structure are characterized by thermal gravity analysis, field emission scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, nitrogen gas adsorption/desorption measurement, and UV/vis spectroscopy. The results obtained show that the hybrid TiO₂-SiO₂ structure possesses both anatase and rutile phases, along with amorphous SiO₂. Its specific surface area is determined to be 141.1m²/g, and its pore size to be 3.77nm. Light harvesting within the visible-light range is found to be enhanced by the use of this hybrid TiO₂-SiO₂ structure. Moreover, the photocatalytic activity and stability are also improved, as demonstrated by the degradation of methylene blue dye under UV irradiation.