Synthesis of nanosized amorphous and nanocrystalline TiO2 for photochemical oxidation of methomyl insecticide in aqueous media

Aqueous solution loaded with methomyl insecticide is photocatalytically treated upon UV radiation and TiO2 in a green sustainable oxidation technique. TiO2 is a highly promising photocatalytic oxidation method, whereas the main findings is increasing the surface area for maximizing the treatment efficiency. Herein, TiO2 was synthesized via sonochemical hydrolysis technique and amorphous TiO2 (TM100) was obtained. Further, annealing of amorphous TiO2 at 500 oC resulting in anatase phase TiO2 (TN500). The phase structure of the both samples was confirmed by high-resolution transmission electron microscope (HR-TEM). The results revealed that the materials exhibited high methomyl removal efficiency due to its nanostructure nature. The optimum TM100 and TN500 for the treatment were 40 and 20 mg/L and resulted in 99.5 and 100% methomyl removal, respectively. Furthermore, pH and H2O2 effect were studied. Additionally, high correlation was attained between empirical and modelled values with a second-order kinetic model for the two processes.