Persulfate Promoted ZnIn2S4 Visible Light Photocatalytic Dye Decomposition

In this work, a synergistic way for promoting the ZnIn2S4 nanoparticle photocatalysis coupled with persulfate (PS) under LED visible light was proposed. The ZnIn2S4 nanoparticle was prepared through a hydrothermal procedure and studied by diversified characterizations. When 1 mmol/L PS was added, 86% of methyl orange (MO) with the beginning amount of 15 mg/L was decolorized at the ZnIn2S4 dosage of 0.2 g/L and pH of 6 after 120 min treatment. The ZnIn2S4/PS process presented a good stability during five cyclic utilizations. Besides, the scavenger addition tests proved the sulfate radical and superoxide radical were the main species for the MO elimination. The chemical oxygen demand and total organic carbon results indicated that the synergistic system could improve the degradation and mineralization effects for the MO. In summary, the coupling ZnIn2S4/PS system presented a favorable synergistic photocatalytic performance, which not only could improve the separation of electron and hole and then activate PS, but also promote the decomposition of MO.