Construction Of Visible Light-response Ag₃PO₄-based Composite Photocatalysts And Investigation Of Their Properties

The Ag₃PO₄/g-C₃N₄,Ag₃PO₄/MFe₂O₄（M=Zn,Ni,Co）and Ag₃PO₄/rGO/CoFe₂O₄were synthesized and characterized by XRD,SEM,TEM,XPS,TG,UV-vis DRS,FT-IR,etc.The photocatalytic activities of as-synthesized composites were evaluated by degrading organic dyes and antibiotics,and the performance enhancement and photocatalytic mechanisms were also proposed.The main conclusions are as follows:The Z-scheme Ag₃PO₄/g-C₃N₄ was synthesized by a sample hydrothermal method.The photocatalytic performance of Ag₃PO₄/g-C₃N₄ for methyl orange degradation was higher than Ag₃PO₄,but was similar with Ag₃PO₄ for tetracycline degradation.In Ag₃PO₄/g-C₃N₄ system,h⁺and O₂^·-were the main reactive species for methyl orange degradation,while h⁺and H₂O₂ were the main reactive species for tetracycline removal.Magnetic Ag₃PO₄/MFe₂O₄（M=Zn,Ni,Co）composite was hydrothermally synthesized.The introduction of MFe₂O₄ can increase the surface area and visible light absorption ability of Ag₃PO₄.Among the three composites,Ag₃PO₄/CoFe₂O₄ exbibited the best photocatalytic performance for methyl orange,methylene blue,tetracycline and levofloxacin degradation.Due to the photo-generated electrons and holes of MFe₂O₄easily recombined,thus they cannot participate in the photocatalytic reaction.CoFe₂O₄promoted the separation and transfer of photo-induced carriers,which inhibited the reduction of Ag⁺,thereby improving the stability of Ag₃PO₄.Magnetic Ag₃PO₄/rGO/CoFe₂O₄ was synthesized via a solvothermal and precipitation method.The ternary catalyst showed an excellent adsorption-photocatalysis performance for removing levofloxacin due to rGO improved the adsorption ability and charge separation efficiency of the catalyst.The degradation efficiency of levofloxacin in river water,lake water and secondary effluent by the ternary catalyst reached to 90%.¹O₂was the main reactive species for levofloxacin degradation and four possible degradation routes of levofloxacin were proposed.After five cycles,the removal efficiency of levofloxacin from the real water matrices by the ternary catalyst was above 80%.Figure 57;Table 8;Reference 136...