Ternary nanocomposite ZnO-g–C3N4–Go for enhanced photocatalytic degradation of RhB

Abstract

The degradation of organic dyes and other pollutants has always been one of the great challenges facing mankind today. So our work designed and improved a novel composite, by using zinc oxide (ZnO) nanoparticles to modify porous carbon nitride (g-C 3 N 4 ), and then load graphene oxide (Go) nanosheets. These prepared binary and ternary composites with different weight ratios were subjected to a series of tests. The results showed that when the weight ratio of g-C 3 N 4 was 40%, the binary composite ZnO-g-C 3 N 4 transferred its absorption edge to lower energy and had the best photocatalytic performance. Moreover, the addition of Go immensely cut down the recombination of photo-generated carriers and enhanced the absorption in the visible light range. The ZnO-g-C 3 N 4 (40%)-Go (15%) displayed 98% degradation efficiency in 100 min, the rate was about 2.23 times than ZnO-g-C 3 N 4 (40%). XRD, XPS, TEM proved the successful hybridization of the composite, and PL explained the causes for the amendment of photocatalytic efficiency. The conduction band and valence band potential of the material were calculated by VB-XPS, and combined with the free radical capture experiment proved the most effective free radical in this experiment and proved the reaction mechanism of the photocatalytic reaction. Through the photocurrent and EIS the results analyzed the high responsivity of the material and the low photogenerated e − /h + recombination rate. In brief, the interface effect and synergistic effect of the ternary heterojunction greatly enhanced the photocatalytic degradation of toxic dyes. • The sample prepared by hydrothermal method has good photocatalytic performance. • The reasons for the increase of photocatalytic activity were analyzed. • The supported photocatalyst was prepared to obtain good recoverability. • Possible photocatalytic mechanism and degradation pathway of RhB by ZnO-g–C 3 N 4 –Go were proposed. • We used VB-XPS combined with the reaction potential of various free radicals to infer the most effective free radicals.