Synthesis and visible-light photocatalytic activity of In, S-TiO2@rGO nanocomposite for degradation and detoxification of pesticide atrazine in water

The visible-light activated In, S-TiO2@rGO nanocomposite was prepared using an innovative ultrasonic-assisted solvothermal method. The products were characterized by XRD, FT-IR, Raman, SEM, HRTEM, TGA and UV-Vis DRS. A considerable red shift in absorption edge of TiO2 was observed after co-doping with In and S. Co-doping of TiO2 with In and S elements and compositing with rGO significantly enhanced its visible-light photocatalytic activity. The complete degradation and 95.5% mineralization of 20 mg/L atrazine (ATZ) was attained at 3.0 mol % of In, 1 mol% of S and 5 wt% of rGO within 20 min. Reaction with % OH at the surface of catalyst was the main mechanism contributed in degradation of ATZ in the developed photocatalytic process. As-made In, S co-doped TiO2@rGO nanocomposite could preserve its catalytic activity during four consecutive recycles for the ATZ removal process. The cytotoxicity of fresh and photocatalytic-treated ATZ solutions assessed using the human hepatic cells (HepG2) indicated that ATZ solution in the developed PCO process could be considerably detoxified.