Synthesis of yolk-shell structure Fe3O4/P(MAA-MBAA)-PPy/Au/ void/TiO2 magnetic microspheres as visible light active photocatalyst for degradation of organic pollutants

Yolk-shell magnetic Fe3O4/P(MAA-MBAA)-PPy/Au/void/TiO2 microspheres have been prepared as visible light active photocatalyst. In this structure, the Fe3O4/P(MAA-MBAA)-PPy core-shell support provides magnetic properties for the catalyst and a large number of binding sites for the Au nanoparticles. In addition, coupling TiO2 with Au nanoparticles can extend the range of absorbable sunlight and enhance electron hole separation. The test of degrading rhodamine B (RhB) under simulated visible light was used to verify the photocatalytic activity of the photocatalyst. The results showed that the photocatalyst exhibited favorable catalytic properties within 90 min in the case of using 4 mg itself. The improved performances were ascribed to the unique yolk-shell structure, which on the one hand greatly improves the light utilization, on the other hand favors full contact of the dye because of the porous appearance of the outer shell. Furthermore, the existence of magnetic core was beneficial to the recycling of the photocatalyst. And the recycling results demonstrated that the catalyst efficiency was maintained at 70.2% even after six recycling experiments. This work not only displays a new material for the degradation of organic dyes, but also provides a new approach for the synthesis of yolk-shell structure photocatalysts. A magnetic recyclable Fe3O4/P(MAA-MBAA)-PPy/Au/void/TiO2 photocatalyst with yolk-shell structure is synthesized and has excellent catalytic properties. [Display omitted] •Two-step Ostwald ripening method was used to prepare hollow yolk-shell catalyst.•The magnetic polymer core was first used to anchor the Au NPs to couple with TiO2.•The magnetic core facilitates the recycling of the photocatalyst.•The yolk shell structure can increase light capture and increase light utilization.•The SPR effect of Au NPs can extend the light absorption range of TiO2 catalysts.