Photocatalytic degradation of emerging pollutants under visible light radiation using NiS2/S-doped g-C3N4 nanostructures

NiS2/S-doped g-C3N4 (NiS2/CNS) nanocomposites were synthesized and used as photocatalysts for the degradation of Rhodamine B (RhB) (8 mg L−1, 100 mL) as a model harmful dye under the visible light radiation (λ>400 nm). It was also found that the adsorption ability was greatly increased after growing the NiS2 NPs on the CNS sample regardless of NiS2 loading value, implying the NiS2 played a key role in adsorption of RhB molecules on the photocatalyst surface. The optimal NiS2 loading value in the NiS2/CNS composites was 5.9 wt% having a reaction rate constant equal to 0.011 min-1, which was about 3.1 as well as 26.1 times faster compared with those of the CNS (0.0035 min-1) and bulk g-C3N4 (0.00042 min-1) toward RhB degradation under visible light radiation. The optimized photocatalyst was capable of showing a high efficiency for phenol photodegredation as a light insensitive pollutant. Hence, the synergistic effects originated from combining sulphur doping and in situ growing of NiS2 NPs in one material enhanced the physicochemical properties of carbon nitride materials.

Keywords:

nanocomposites , Photocatalyst , Visible light irradiation , S-doped g-C3N4 , Rhodamine B