Preparation and photocatalytic activity of porous spherical TiO2 particles comprised of H3PW12O40 in hydrophobic nanopores

Porous TiO2 sphere particles were prepared by impregnating titanium (IV) oxysulfate solutions into organic monolith particles, with subsequent calcination in air. The powder possessed pores of meso-order. Its crystalline phase was anatase. Then, 12 Tungsto(VI) phosphoric acid (PW12) was present in the mesopores. The entire surface was modified to be hydrophobic by octadecylphosphonic acid (ODP). Subsequent UV illumination in water removed the PW12 and ODP adsorbed onto the outer sphere surface. The obtained spherical TiO2 particles with hydrophobic acidic nanopores exhibited high photocatalytic performance against the removal of 1,4-dioxane in water. Detailed analysis revealed that this material removed both 1,4-dioxane and ethylene glycol diformate (EGDF), the main intermediate of the photocatalysis of 1,4-dioxane. Results suggest that hydrophobic acidic nanopores enhance adsorption of EGDF in water and play an important role in the overall photocatalytic performance of this system.