Photoredox degradation of different water pollutants (MO, RhB, MB, and Cr(VI)) using Fe–N–S-tri-doped TiO2 nanophotocatalyst prepared by novel chemical method

Abstract Fe–N–S-tri-doped TiO 2 (FeNS-TiO 2 ) was synthesized by a simple one-step hydrothermal method. The as-synthesized samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The photocatalytic activities of as-synthesized samples were tested by the oxidation of methyl orange (MO), rhodamine B (RhB), methylene blue (MB) and the reduction of aqueous Cr(VI) under visible-light ( λ  > 420 nm) irradiation, and compared with N-dope P25 (N-P25) and the undoped TiO 2 . Besides, the effects of the coexistence of MO, RhB, and MB on FeNS-TiO 2 -mediated photocatalytic reduction of aqueous Cr(VI) were also studied. The results indicated FeNS-TiO 2 displayed higher visible-light-activated photocatalytic activity than N-P25 and the undoped TiO 2 . Otherwise, FeNS-TiO 2 showed the coexistence of MB enhanced the photocatalytic reduction of Cr(VI), whereas the coexistence of MO and RhB retarded the photocatalytic reduction of Cr(VI) over FeNS-TiO 2 . Moreover, a possible photocatalytic mechanism is discussed.