A Novel Visible-Light-Driven Photo-Fenton System Composed of Fe-Doped CdIn2S4/g-C3N4 Heterojunction and H2O2 to Remove Methyl Orange

In this study, ternary Fe-doped CdIn2S4/g-C3N4 catalyst has been formed by a wet impregnation-calcination method and then characterized by XRD, FE-SEM, TEM, FT-IR, DRS, and photo-luminescence spectra. With the experimental conditions of simulating visible-light irradiation, the photocatalytic degradation performance of methyl orange (MO) aqueous solution was studied by adding H2O2 as oxidant. After a series of characterization methods and photocatalytic activity tests on MO dye, the following conclusions were drawn: The ternary Fe-CdIn2S4/g-C3N4 heterojunction has a wider visible-light response range than that of g-C3N4 and binary CdIn2S4/g-C3N4 catalysts; the corresponding forbidden bandwidth has been narrowed. The recombination rate of carriers generated under illumination has been greatly reduced; the amount of dark adsorption has been greatly improved, which in turn promotes the progress of the photocatalytic reaction. It is speculated that its superior dark adsorption potential of the Fe-CdIn2S4/g-C3N4 is due to the positively charged Fe3+ and the negatively charged MO anionic dye, which will generate strong attraction between them.