Preparation Of Silver Carbonate Composite And Its Visible-light Photocatalytic Degradation Of Bisphenol A

Semiconductor photocatalytic oxidation technology has the characteristics of simple equipment,low energy consumption,mild reaction conditions and so on,so it has become one of the effective ways to solve environmental pollution in the field of environment.Ag₂CO₃ photocatalytic material has good catalytic oxidation ability due to its unique electronic structure and narrow band gap.However,pure Ag₂CO₃photocatalyst is prone to photocorrosion and difficult to be separated and recovered,which seriously affects its practical application.Based on this,in order to improve the photocatalytic activity and stability of Ag₂CO₃,this article combines Ag₂CO₃ with other materials,building practical Ag₂CO₃ composite photocatalysts.And the performance and mechanism of bisphenol A（BPA）degradation by composite photocatalyst were discussed.The specific contents and conclusions are as follows:（1）The ZnFe₂O₄/Ag₂CO₃ composite photocatalytic material was prepared successfully.the materials were characterized by SEM、XRD、FT-IR、BET and other methods.The results show that after modification,the light absorbing properties of the composites are increased,and the electronic-hole pair recombination rate significantly reduced.（2）BPA was used as the target pollutant to evaluate the photocatalytic performance of composite catalysts.The results showed that the prepared ZnFe₂O₄/Ag₂CO₃ composite exhibited higher photocatalytic activity compared with pure ZnFe₂O₄ or Ag₂CO₃.The optimal mass ratio of ZnFe₂O₄ and Ag₂CO₃ in the composite photocatalytic materials was 1:2,and the removal rates of BPA and TOC were 93.18%and 65.35%,respectively.The results showed that the optimal conditions for the photocatalytic degradation of BPA by the composite catalyst ZnFe₂O₄/Ag₂CO₃（1:2）were as follows:catalyst dosage 0.8g/L,initial solution concentration 20mg/L,solution pH=6.After four repeated experiments,the photocatalytic stability of the composite materials of ZnFe₂O₄/Ag₂CO₃ composite was significantly better than that of pure Ag₂CO₃,which effectively relieved the corrosion of Ag₂CO₃.（3）A series of rGO-ZnFe₂O₄/Ag₂CO₃ composite were prepared.The materials were characterized by SEM、XRD、FT-IR、BET and other methods.The results show that due to the addition of rGO,the reunions of composite photocatalytic are reduced,and the surface area is significantly increased.（4）BPA was used as the target pollutant to investigate the photocatalytic activity of rGO-ZnFe₂O₄/Ag₂CO₃（1:7:16）composite photocatalyst under visible light.The experimental results showed that rGO-ZnFe₂O₄/Ag₂CO₃（1:7:16）had the best photocatalytic effect,and the degradation rate was 2.83 times and 1.39 times of that of pure Ag₂CO₃ and ZnFe₂O₄/Ag₂CO₃（1:2）,respectively.The photocatalytic degradation rate of BPA was greatly improved.Composite material degradation of BPA removal rate is still high after four cycles.（5）The active species in photocatalytic reaction were detected by free radical trapping experiment.Experimental data show that h⁺、·OH and·O₂^-are all involved in the photodegradation process of ZnFe₂O₄/Ag₂CO₃ and rGO-ZnFe₂O₄/Ag₂CO₃composites for BPA,and their corresponding contribution is h⁺>·OH>·O₂^-.（6）The intermediate products in the photocatalytic degradation of BPA by ZnFe₂O₄/Ag₂CO₃ composites were analyzed by GC-MS test,and the possible degradation path of BPA was speculated.