Sol–gel immobilization of SiO2/TiO2 on hydrophobic clay and its removal of methyl orange from water

In this study, SiO2/TiO2–organoclay hybrids with high adsorption capability and high photocatalytic activity were synthesized by immobilizing mixed silica and titanium dioxide nanoparticles on organically modified clay via a hydrothermal sol–gel method. Addition of negatively charged silica particles enhanced the uniform dispersion of titanium dioxide nanoparticles on organoclay layers by decreasing the system tension, which resulted in high photocatalytic activity of SiO2/TiO2–organoclay hybrids. The high adsorption capability endowed by organically modified clay enriched the organic compounds around the photoactive sites, and thus greatly improved the photodegradation efficiency. Combining the high adsorption capability of organoclay with the high photocatalytic activity of TiO2 nanoparticles, SiO2/TiO2–organoclay hybrids were promising and cost-effective photocatalysts in removal of pollutants from wastewater.