Visible-light-induced In,S-TiO۲@rGO with enhanced photocatalyticactivity for detoxification of atrazine

The visible-light activated In,S-TiO۲@rGO nanocomposite was prepared using an innovativeultrasonic-assisted solvothermal method. The XRD patterns indicated the anatase structure forTiO۲ co-doped with indium and sulfur elements. FT-IR and Raman spectra analysis confirmedthe presence of rGO in nanocomposites. In addition, SEM and HRTEM images confirmed thepresence of mono-dispersed TiO۲ nanoparticles on rGO sheets. A considerable red shift inabsorption edge of TiO۲ was observed after co-doping with In and S. Co-doping of TiO۲ with Inand S elements and compositing with rGO significantly enhanced its visible-light photocatalyticactivity which was strongly affected by the amount of In, S and rGO to TiO۲ ratio in thenanocomposite. The complete degradation and ۹۵.۵% mineralization of ۲۰ mg/L atrazine (ATZ)was attained in the photocatalytic oxidation (PCO) process within ۲۰ min with In,S co-dopedTiO۲@rGO nanocomposite. The rate of ATZ degradation in the PCO process with In,S co-dopedTiO۲@rGO nanocomposite was ۸۰ times of that with pure TiO۲ as catalyst under visible-lightirradiation. The enhanced photocatalytic activity of the In, S co-doped TiO۲@rGO is related tothe synergistic effect of dopants contributing to improved visible light absorption and decreasedrecombination rate of the charge carriers. The degradation studies using various scavengersshowed that hydroxyl radical was the main active species contributed in the photocatalyticdegradation of ATZ under the selected conditions. In addition, the rate of ATZ degradation andmineralization in the photocatalytic process with the TiO۲@rGO nanocomposites as catalyst was۰.۲۴۸ and ۰.۱۶۹ min−۱, respectively, which was remarkably greater than TiO۲. The preparednanocomposite was found to be a reusable and durable catalyst for visible light photocatalyticdegradation of ATZ. As-made In,S co-doped TiO۲@rGO nanocompsite could preserve itscatalytic activity during four consecutive recycles for the ATZ removal process. The cytotoxicityof fresh and photocatalytic-treated ATZ solutions assessed using the human hepatic cells(HepG۲) indicated that treating ATZ solution in the developed PCO process could beconsiderably detoxified.

کلیدواژه ها:

TiO۲ doping ، Graphene oxide ، Nanocomposite ، Photocatalytic process