Preparation Of Bismuth Based Photocatalyst And Their Performance In Removing Antibiotics

BiOCl/Bi microspheres,BiOBr microspheres and magnetic BiOBr/Mn Fe₂O₄composite were solvothermally synthesized and characterized by XRD,SEM,XPS,UV-vis DRS,FT-IR.The photocatalytic activities of as-synthesized catalysts were evaluated by degrading tetracycline（TC）,and the mechanism for photocatalysis and persulfate（PDS）activation were proposed.The adsorption-photocatalysis performance of BiOCl/Bi microspheres was higher than that of BiOCl.The Freundlich isothermal adsorption model demonstrated the chemisorption between BiOCl/Bi and TC.The light response capability of BiOCl/Bi was enhanced due to the surface plasmon resonance effect,and the defective energy level caused by oxygen vacancies facilitates the separation and transfer of photo-generated charge.Under visible LED light（Vis-LED）irradiation for 90 min,80.3%of TC was degraded by BiOBr/PDS/Vis-LED system,which was higher than those of PDS/Vis-LED,BiOBr/PDS and BiOBr/Vis-LED systems.On one hand,the introduction of PDS facilitates the separation of photo-generated electron/hole pairs within BiOBr;on the other hand,TC degradation was improved by the formation of SO₄^·-by PDS activation.The magnetic BiOBr/Mn Fe₂O₄ nanocomposite was solvothermally prepared.Under visible light irradiation for 90 min,76.5%of TC was removed by the BiOBr-Mn Fe₂O₄-10/PDS/light system,which was superior to BiOBr/PDS or Mn Fe₂O₄/PDS systems.The photo-responsive capacity,recovery property and PDS activation performance of BiOBr were enhanced due to the introduction of Mn Fe₂O₄.The Mn and Fe ions on the surface of Mn Fe₂O₄ can activate PDS,and the redox cyclic reaction between them facilitates PDS activation.The TC degradation in actual water by BiOBr-Mn Fe₂O₄-10 system was inhibited due to the inorganic anions.Figure 53;Table 14;Reference 164...