Wool-ball-like BiOBr@ZnFe-MOF composites for degradation organic pollutant under visible-light: Synthesis, performance, characterization and mechanism

ZnFe-MOF was simply fabricated from iron chloride hexahydrate, zinc nitrate hexahydrate and terephthalic acid in a 1:1:1 M ratio by one-step solvothermal method. Wool-ball-like BiOBr@ZnFe-MOF composites were synthesized by addition of Bi3+, CTAB and ZnFe-MOF using a simple solvothermal process. The optimum BiOBr@ZnFe-MOF demonstrated excellent degradation performance for rhodamine B and tetracycline under visible light. The as-synthesized photocatalytic materials were characterized by XRD, SEM, EDS, XPS, FTIR, UV–vis, PL, EIS and BET analysis. It indicated that the doping of a certain amount of ZnFe-MOF on the BiOBr materials have improved the photocatalytic efficiency. The photocatalytic performances of BiOBr@ZnFe-MOF composites were studied by degradation of rhodamine B (RhB), methylene blue (MB), methyl orange (MO) and tetracycline (TC) under the visible-light irradiation, the degradation efficiency of RhB, MB, MO and TC were 99%, 84.1%, 10.9% and 79%, respectively. Moreover, BiOBr@ZnFe-MOF composite exhibited excellent reusability and stability during the process of cyclic experiments. The reaction mechanism and possible photocatalytic mechanism of RhB degradation were also discussed in detail by the free radical capture experiment.