Fabrication and photocatalytic activity of magnetic core@shell ZnFe2O4@Ag3PO4 heterojunction

Novel ZnFe2O4@Ag3PO4 core@shell heterojunction photocatalysts were fabricated through a solvothermal-liquid phase deposition method. Ag3PO4 was evenly dispersed on the surface of ZnFe2O4 microrods and approximately 150 nm in size. ZnFe2O4@Ag3PO4 composite photocatalysts could be recovered rapidly using the ferromagnetism of ZnFe2O4. Experimental results from the photodegradation of methylene blue (MB) indicated that the 14 wt% ZnFe2O4@Ag3PO4 photocatalyst sample showed the best catalytic activity by degrading 93% MB after 6 min of irradiation，the rate of degradation of the composite was 1.39 and 11.6 times those of Ag3PO4 and ZnFe2O4, respectively, which is attributed to the effective charge separation by the core@shell heterojuction between the ZnFe2O4 and Ag3PO4．The main mechanism during degradation was the direct oxidation by the photo-induced holes.