One-pot-solid preparation of novel three-dimensional FexS1-x/g-C3N4 heterostructures for efficient photocatalytic mixed-pollutants removal

Abstract In order to overcome the problem of low photocatalytic rate and only visible light response of g-C3N4, the 3D FexS1-x/g-C3N4 heterojunction was prepared via a simple one-pot solid method. The X-Ray Diffraction (XRD) and scanning electron microscope (SEM) results demonstrated that the FexS1-x/g-C3N4 heterojunction was established and a g-C3N4 nanosheet was tightly bound to FexS1-x. Compared with g-C3N4 samples, FexS1-x coupling resulted in substantial enhancement of visible light absorption, moreover, the bandwidth of heterojunction was also expanded. In addition to effectively degrading RhB and reducing Cr(VI), the redox performance of FexS1-x/g-C3N4 was also increased in the Cr(VI)/RhB mixed system. Through a variety of tests, the enhanced synergistic photocatalytic activity of the 3D FexS1-x/g-C3N4 heterojunction was attributed to enhancement of the separation of e- and h+ in FeS2, which resulted from the effective conversion of FeS into FeS2 under UV-light irradiation. The type II heterojunction structure that was produced via one-pot solid fabrication also inhibited the recombination of electron/hole pairs. FexS1-x doping and heterojunction building improve the photocatalysis capacity of g-C3N4 and broaden the visible-light response of pure g-C3N4.