Highly active mesoporous SiO2-TiO2 based nanocomposites for photocatalytic degradation of textile dyes and phenol

Abstract

Titania-silica nanocomposites (20% SiO₂-TiO₂, 30% SiO₂-TiO_2, 40% SiO₂-TiO₂ and 50 % SiO₂-TiO₂) with tailored morphology and tunable band energy have been synthesized successfully via micro emulsion method. The morphology, chemical composition, band gap energy and stability of prepared nanocomposites were investigated by XRD, SEM/EDX, FT-IR, DRS and TGA. While textural parameters such as surface area, pore volume, and pore diameter were evaluated by nitrogen adsorption-desorption isotherms. The prepared nanocomposites were employed for photocatalytic degradation of phenol and dyes (methyl yellow, auramine O, turquoise blue G) under visible light irradiations. The results of photocatalytic degradation and kinetic parameter (K_app) strongly suggest that 20% SiO₂-TiO₂ showed remarkable photocatalytic efficiency in comparison to SiO₂-TiO₂ nanocomposites with high silica contents. These findings proved significantly that 20% SiO₂-TiO₂ have marked impact on the photocatalytic efficiency due to its high pore volume, more diameter, high availability of anatase TiO₂ in nanocomposite and reduced bandgap energy.