Controllable Synthesis And Photocatalytic Activity Of Nana-ZnO/Bi₂₄O₃₁Br₁₀ Composite Magnetic Photocatalyst

The photocatalytic degradation of organic pollutants by semiconductor photocatalytic materials has advantage of friendly to environment and low cost in the water environment,and is expected to be widely used.Among them,BiOX?X=Cl,Br,I?has attracted much attention in the field of photocatalysis due to its unique layered structure and narrow band,especially the novel bismuth oxygen-rich Bi_xO_yX_z?X=Cl,Br,I?has become the focus of research.Starting from the synthesis and composite modification of Bi_xO_yX_z,the solvothermal method was used to controllable synthesize Bi₂₄O₃₁Br₁₀ with lower conduction band.The catalytic redox potential of the product was investigated,and the new oxygen-rich type improve by compounding multi-stage semiconductor heterojunction,which can improve the photocatalytic activity and stability of the novel bismuth oxygen-rich Bi₂₄O₃₁Br₁₀.The synthesis conditions of the new oxygen-rich polyfluorene Bi₂₄O₃₁Br₁₀ were investigated.When the pH of the Bi₂₄O₃₁Br₁₀ precursor was equal to 10,Bi₂₄O₃₁Br₁₀was obtained in the paper.The test showed that the conduction band was decreased,and the photogenerated electrons were beneficial to increase the catalytic activity,which was confirmed by a reduction reaction of catalytic potassium dichromate.The preparation of nano-ZnO/Bi₂₄O₃₁Br₁₀ was carried out on a suitable proportion of nano-ZnO on Bi₂₄O₃₁Br₁₀ to detect its ability to absorb ultraviolet light and visible light.The results show that the catalytic effect of nano-5at%ZnO/Bi₂₄O₃₁Br₁₀ is not only higher than that of Bi₂₄O₃₁Br₁₀,but also higher than that of nano-ZnO.The heterojunction structure of the composite promotes the decrease of photo-generated electron-hole complex ratio.The magnetic nano-ZnO/Bi₂₄O₃₁Br₁₀-SrFe₁₂O₁₉ composite catalyst was synthesized by two-step solvothermal method.The three-component composite catalyst had a n-p-n heterojunction.The barium ferrite has good magnetic properties and contributes to the recovery of the catalyst.After five cycles of recovery,the catalyst still has high catalytic activity and magnetic property.RhB photodegradation was used as a probe test to assess the efficiency of photocatalytic degradation of organic wastewater by composite catalysts,and preliminary experiments on visible light degradation of aged landfill leachate were carried out.After photocatalytic reaction,its chromacity color and COD were tracked and monitored.The experimental results show that after 4 hours of visible light irradiation,the chromaticity of landfill leachate is significantly reduced,and the COD value is increased,indicating that macromolecular pollutants are degraded into small molecular organic substances,that is,the bonds of colored groups are broken,which is beneficial to the terminal treatment of landfill leachate achieves the discharge standard.