Preparation of fly ash zeolite supported ZnO/Co3O4 catalyst for the photocatalytic degradation of xanthate under visible light

The development of high-value utilization technology of fly ash plays an important role in promoting environmental protection and social and economic development. In this paper, a novel composite photocatalyst Z-ZnO/Co₃O₄ is synthesized by loading ZnO/Co₃O₄ on the surface of fly ash zeolite. In addition, the properties of Z-ZnO/Co₃O₄ are characterized by variety of methods. The results show that the surface of cubic A-type zeolite is coated with ZnO/Co₃O₄ composite, forming an open spherical flower-like structure with a typical p-n heterostructure, which plays a positive role in reducing the band gap and the recombination rate of photogenerated electrons and holes of the composite catalyst, thus improving the degradation efficiency of xanthate. The degradation rate toward xanthate of Z-ZnO/Co₃O₄ is 97.62 % after simulated sunlight irradiation for 120 min under the optimum conditions, which is higher than that of Z-ZnO and Z-Co₃O₄, respectively. Meanwhile, the experimental results indicate that h⁺ plays a leading role in the catalytic reaction system. Furthermore, degradation rate toward xanthate of Z-ZnO/Co₃O₄ decreases slightly from 97.62 % to 88.24 % after five cycles, indicating its remarkable durability and stability.