Large mesoporous micro-spheres of WO3/TiO2 composite with enhanced visible light photo activity

The large mesoporous microspheres of pure titania (TiO2) and WO3/TiO2 composite have been synthesized using Pluronic P123 template and titanyl sulfate and ammonium tungstate precursors. Titania oligomers hydrolyzed from TiOSO4 precursor can assemble with pluronic P123 to form a large pore mesostructure. The sulfate ions generated by titanyl sulfate forms the hydrogen bonding interactions with the hydrophilic segments (PEO blocks) of pluronic P123. The composites have large pore sizes as compared to the pure sample due to co-assembly of titania oligomers with ammonium and sulfate ions by S0NH4+X−I+ process. A mechanism has been proposed to explain the formation of large-pore mesoporous materials with tunable pore diameters. A 5.0% composite shows far superior photo activity as compared to pure TiO2, Degussa P-25, pure WO3 and 5.0% nonporous composite in the degradation of methyl orange (MO) under visible light due to unique mesostructure, large mesoporous microspheres and presence of tungsten.