Fabrication of oxygen-rich vacant 3D Zn–CuBi2O4/MMT photocatalysts and the enhancement of its photocatalytic performance

Abstract

Semiconductor catalytic materials have excellent photocatalytic degradation performance for organic pollutants, and photocatalytic degradation is considered to be the most promising technology for environmental pollution treatment. Bismuth-based bimetallic oxide CuBi2O4 is widely recognized as one of the most valuable and promising semiconductor photocatalytic materials because of its narrow bandwidth, strong visible light absorption and excellent chemical stability. To further improve the photocatalytic activity of CuBi2O4, the Zn-doped CuBi2O4/montmorillonite composites were prepared by employing a synergistic control strategy of doping and oxygen vacancies (OVs), which efficiently regulated the electronic structure and the number of active sites to achieve a rapid separation of photogenerated charges. The doping of zn2+ significantly increased the quantity of oxygen vacancies in the prepared materials. The BET revealed that the incorporation of montmorillonite (MMT) greatly increased the specific surface area of CuBi2O4. The experimental findings indicated that 5 % Zn–CuBi2O4/MMT0.6 possessed abundant oxygen vacancies and longer fluorescence lifetime, resulting in better photocatalytic performance. The removal rate of butyl xanthate was 99.31 % in 40 min, and the removal rate of tetracycline hydrochloride (TC) was 93.17 % in 180 min. The 5 % Zn–CuBi2O4/MMT0.6 could effectively inhibit e−/h+ complexation and provide richer catalytic active sites by doping to construct a flower-like oxygen-rich vacancy defect structure, which significantly improves its catalytic performance. The results of the cycling experiments showed that the stability and reproducibility of the 5 % Zn–CuBi2O4/MMT0.6 composites were excellent, the present study provides an innovative idea for the development of efficient and stable visible light photocatalytic applications.