Magnetic MFe2O4-Ag2O (M = Zn, Co, & Ni) composite photocatalysts and their application for dye wastewater treatment

Silver oxide is a high-performance visible-light-driven nanoparticle photocatalyst. However, its high cost and difficult recovery limit its wide application. Constructing a magnetic composite is a smart strategy to effectively utilize nanoparticle photocatalysts with acceptable performance maintenance. In this study, three magnetic ferrite supports, that is, CoFe 2 O 4 , ZnFe 2 O 4 , and NiFe 2 O 4 , were used as support to load Ag 2 O and construct Ag 2 O/MFe 2 O 4 composites to lower the Ag consumption and intensify the recovery rate. The photoactivity, stability, and magnetic recovery of the three composite magnetic photocatalysts were evaluated by using four typical organics. The results of the batch experiment confirm that Ag 2 O/MFe 2 O 4 (60%) possesses a good photoactivity and stability. However, Ag 2 O/ZnFe 2 O 4 exhibits a better photoactivity and higher magnetic recovery based on cycling during the semi-continuous process. The ferrites are inert for photocatalysis process without significant effect on Ag 2 O photocatalytic performance, but increase the surface area and improve the recovery rate as magnetic composite carriers.