Construction of Z-scheme Ag/InS/ZnO nanorods composite photocatalysts for degradation of 4-nitrophenol.

Herein, Ag/InS/ZnO nanorods (NRs) composite photocatalysts were successfully prepared via simple methods. Significantly, hydroxyl radical active substances were found in the electron spin resonance tests of InS/ZnO NRs and Ag/InS/ZnO NRs, which indicates that the oxidation reaction that oxidizes water or hydroxide ions into hydroxyl radicals occurs on the valence band of ZnO NRs. It suggests that Z-scheme heterojunction was successfully constructed. In the photocatalytic experiments of degrading 4-nitrophenol (PNP), the Ag/InS/ZnO NRs composite exhibits higher photocatalytic activity than ZnO NRs, InS, Ag/ZnO NRs and InS/ZnO NRs. The characteristic peak of PNP disappears completely in 50 min. The enhanced photocatalytic performance can be attributed to the formation of Z-scheme heterojunction between ZnO NRs and InS. In addition, local surface plasmon resonance of Ag and Schottky junction formed between Ag and InS also promote the photocatalytic activity.