Efficient visible light-induced photocatalytic removal of paraquat using N-doped TiO2@SiO2@Fe3O4 nanocomposite

The removal of organic pollutants by heterogeneous photocatalysts is still faced with several challenges including the catalyst activity in the visible light range and its recovery. In relation to that, the synthesis of N-doped TiO2/SiO2-based nanomagnetic photocatalyst (N-TiO2@SiO2@Fe3O4) was successfully made through a simple sol-gel method in this study. The morphology of the nanocomposite was then identified and confirmed by XRD, FT-IR EDX, SEM, XPS and BET analytical techniques. After that, the influential factors affecting the removal efficiency of PQ was investigated in detail and the optimal conditions were established. Under the conditions of visible light and 180 min of reaction time, the TOC removal efficiency of 84.71% was accomplished. Furthermore, the synthesized photocatalyst almost maintained its efficiency after a run of eight cycles with a negligible loss of 7.88% in the removal efficiency of PQ. Finally, the results revealed that the photocatalyst could be potentially used in treatment technology. (C) 2019 Published by Elsevier B.V.