Reduced graphene oxide wrapped ZnFe2O4 nanospheres as selective magnetically recyclable Photocatalysts under visible light irradiation

Magnetically separable and reusable zinc ferrite/reduced graphene oxide (ZnFe 2 O 4 /rGO) nanocomposite has been prepared by hydrothermal method. The results illustrate that the construction of ZnFe 2 O 4 and rGO occur concurrently in a hydrothermal reaction that initiates the formation of rGO-wrapped ZnFe 2 O 4 nanospheres. The morphological and structural features of the ZnFe 2 O 4 /rGO nanocomposites reveal that the rGO nanosheets anchored to the ZnFe 2 O 4 sphere act as a self-protective clamping layer to avoid the photo corrosion effect under photo irradiations. The nanocomposites express the soft magnetic behavior with high saturation magnetization under annealing temperature at 300 °C, which may attribute to the well-defined crystalline structure and surface defects. In addition, the GZF 300 nanocomposites exhibit the enhanced photocatalytic degradation over Rhodamine B dye which is 3.4, 1.15, and 1.32 times higher than that of ZF, GZF, and GZF 600 over under visible irradiation in 120 min. The GZF 300 nanocomposites demonstrate their ability to degrade RhB efficiently, even after several photocatalysis cycles with high catalyst recovery by its magnetically separable behavior. The high densities of oxygen defects improvise electron transfer from ZnFe 2 O 4 to rGO and delay the recombination process of the nanocomposite, resulting in enhanced visible photocatalytic activity. The strong magnetic properties of rGO wrapped ZnFe 2 O 4 nanocomposite catalysts the easy separation from the suspension system for multiple usages in water treatment.