Visible-Light-Driven Photocatalytic Degradation of Xanthate in Flotation by g-C<sub>3</sub>N<sub>4</sub>/ZnIn<sub>2</sub>S<sub>4</sub> Heterojunction: Experimental and DFT Studies
Yue Zhang, Yunpei Cui, Teng Wang, Jiewei Xie, Jiayou Liu, Xiufeng Zhang, Qianqian Nie, Hesheng Yu
Abstract
Graphitic carbon nitride (g-C 3 N 4 ) and zinc indium sulfide (ZnIn 2 S 4 ) were combined to form CN/ZIS composite materials via a hydrothermal method. The CN/ZIS composites were extensively characterized before they were used for photocatalytic degradation of sodium isobutyl xanthate (SIBX). Results revealed that 3CN/ZIS outperformed other materials, as evidenced by SIBX degradation efficiency of about 8.16 and 5.46 times greater than that of g-C 3 N 4 and ZnIn 2 S 4, respectively. The improved activity results from the combination of g-C 3 N 4 and ZnIn 2 S 4 . The synergistic effect leads to an enlarged surface area, stronger light absorption, more efficient charge carrier separation, and reduced recombination rates. The mechanisms behind the photocatalytic degradation of SIBX using CN/ZIS were then proposed based on density functional theory (DFT) calculations, band structure analysis, and oxidation–reduction potential. The results verified the successful construction of a Type-II heterojunction between g-C 3 N 4 and ZnIn 2 S 4 . Furthermore, cyclic experiments demonstrate that 3CN/ZIS maintains high degradation efficiency after five cycles, indicating strong chemical stability and promising industrial potential.