Synthesis And Photocatalytic Activities Of Magnetic AgBr-based Composite Materials

Three novel magnetic composites?AgBr/Cu/CuFe₂O₄,CoFe₂O₄/AgBr and Ag/AgBr/NiFe₂O₄?were synthesized and characterized by XRD,TEM,XPS,UV–vis and so on.The photocatalytic activities and mechanisms for enhanced performance of the as-obtained composite photocatalysts were evaluated and the main conclusions are as follows:Cu/CuFe₂O₄ was fabricated by a solvothermal method and then AgBr/Cu/CuFe₂O₄composite was prepared via a deposition method.Under visible light irradiation for 60 min,95.2%of Rhodamine B?RhB?was degraded by AgBr/Cu/CuFe₂O₄,higher than that of Cu/CuFe₂O₄ and AgBr.Cu⁰ acted as an electron mediator in the Z-scheme system,which improved separation efficiency of photo-induced charges and kept the high redox capability,resulting in the enhanced photocatalytic activity.Besides,five consecutive cycling RhB photodegradation indicated the good reusability of AgBr/Cu/CuFe₂O₄ photocatalyst.The magnetic CoFe₂O₄ was synthesized by a hydrothermal method and CoFe₂O₄/AgBr with different compositions were obtained via a deposition method.Under visible light irradiation for 60 min,95%of methyl orange?MO?was removed by 20%CoFe₂O₄/AgBr,superior to CoFe₂O₄,AgBr,5%CoFe₂O₄/AgBr and 10%CoFe₂O₄/AgBr,due to the close contact between CoFe₂O₄ and AgBr in 20%CoFe₂O₄/AgBr composite and the improved separation efficiency of photo-generated charges by constructing type-II heterojunction.Moreover,20%CoFe₂O₄/AgBr could be easily recycled and reused.A magnetic plasmonic Ag/AgBr/NiFe₂O₄ composite photocatalyst was prepared by coupling a hydrothermal route with a solvothermal method.Under visible light irradiation,Ag/AgBr/NiFe₂O₄ exhibited a higher photocatalytic activity for RhB degradation compared with NiFe₂O₄ and Ag/AgBr,which was ascribed to the enhanced visible-light adsorption by the surface plasmon resonance?SPR?effect of Ag⁰,and the formed type-II heterojunction between AgBr and NiFe₂O₄ could improve the separation efficiency of photogenerated charges.Three successive cycles confirmed that Ag/AgBr/NiFe₂O₄ photocatalyst was stable.Figure 47,Table 7,Reference 100.