Construction of a ternary staggered heterojunction of ZnO/g-C3N4/AgCl with reduced charge recombination for enhanced photocatalysis

In this study, a series of ternary composite photocatalysts ZnO/g-C 3 N 4 /AgCl(x) (x is the amount of AgCl added, x=0.05, 0.1, 0.15 g) were synthesized, and various characterization methods were used to analyze the morphology, structural and photochemical properties of the above samples. The photocatalytic activity of the obtained samples was evaluated by degrading rhodamine B (RhB) and acid orange (AOⅡ) using a xenon light source (500 w) as a simulated light source. The results shown that within 60 min, the degradation rate of ZnO/g-C 3 N 4 /AgCl(0.1 g) is 99%, which is much higher than the 38% degradation rate of g-C 3 N 4 . After three cycles, the degradation efficiency of RhB and AOII by ZnO/g-C 3 N 4 /AgCl(0.1 g) can still reach 91% and 95%, respectively. Based on the electronic structure analysis of DFT calculations, it is found that a staggered heterojunction structure is formed between g-C 3 N 4 , ZnO and AgCl. The enhanced photocatalytic activity of the ternary composite is mainly attributed to the efficient separation of charge carriers through the synergistic removal of photogenerated electrons in g-C 3 N 4 by ZnO and AgCl. Radical trapping experiments confirmed that •O 2 − and h + were the main active species in the reaction system. As a visible light-responsive catalyst, ZnO/g-C 3 N 4 /AgCl can be effectively applied to the degradation of organic dye pollutants and has broad application prospects.