A novel visible-light-induced double Z-scheme photocatalytic system: NH2-UiO-66/BiOBr/Bi2S3 for degradation of tetracycline hydrochloride and rhodamine B

The unique properties of MOFs make them the best candidates for catalytic and photocatalytic applications. In this research, the NH2-UiO-66 material was prepared by solvothermal method, and different content of NH2-UiO66 was added before the composite growth of Bi2S3 and BiOBr nanomaterials to obtain the NH2-UiO-66/BiOBr/ Bi2S3 ternary composite material. In order to investigate the relationship between the structure and properties of the catalyst, XRD, FT-IR, SEM, HRTEM, UV-vis DRS, XPS and other characterization technologies were used to analyze the structure, morphology, optical properties of the samples, showing that NH2-UiO-66/BiOBr/Bi2S3 have been successfully synthesized. Their photocatalytic performance was evaluated based on the photocatalytic degradation of tetracycline hydrochloride and rhodamine B under visible light. The results show that 2% NH2UiO-66/BiOBr/Bi2S3 has better photocatalytic activity than other materials. Moreover, NH2-UiO-66/BiOBr/Bi2S3 also demonstrated good photocatalytic reusability and stability. The formation of Bi2S3 and BiOBr heterojunctions and the introduction of NH2-UiO-66 with more active sites increase the carrier performance and separation efficiency. Then the valence band and conduction band values of the semiconductor material are calculated through the M-S curve, combined with the forbidden bandwidth deduced by UV-vis DRS and the experimental results of radical trapping, a double Z-type electron transfer mechanism suitable for this system is inferred. Finally, taking RhB as an example, the degradation path of dye pollutants was studied.