Synthesis by sol–gel of WO3/TiO2 for solar photocatalytic degradation of malathion pesticide

In this study, TiO2 modified with WO3 (2 wt.%) was prepared by the sol–gel method, and its photocatalytic activity (PCA) under solar irradiation was evaluated using malathion as the model contaminant. The catalyst was synthesized using tetra butyl orthotitanate (TBT) and ammonium p-tungstate (ApT) as precursors. For comparison, bare TiO2 was also prepared by the sol–gel process. The resulting photocatalysts were characterized by XRD, BET, DRUV–vis, FE-SEM, TEM and STEM. The synthesized TiO2 materials exhibited a crystalline anatase phase with an average particle size of 20 nm. Results of malathion degradation using solar light, indicated that 2%WO3/TiO2 showed better catalytic performance than sol–gel TiO2, achieving a complete degradation after 2 h, while TOC abatement was 63% after 5 h. These results suggest that 2%WO3/TiO2 catalyst is a promising material for solar photocatalytic treatment of water contaminated by pesticides.