Magnetic ZnFe2O4 octahedra: Synthesis and visible light induced photocatalytic activities

Magnetic ZnFe2O4 octahedra with an average size of 10 nm were successfully synthesized via a hydrothermal method with the assistance of sodium oleate. The formation mechanism of the as-prepared ZnFe2O4 was discussed. Its band gap calculated from the adsorption edge was fixed at 1.7 eV, which suggests that it could be excited under visible light irradiation. The ZnFe2O4 nanocrystal bound by {111} faces exhibited good photocatalytic activities in the degradation of Rhodamine B (RhB) under the irradiation of simulated solar light. The enhanced photocatalytic activity can be attributed to the small size and octahedral morphology. Furthermore, the products were superparamagnetic and could be easily recovered from the solution by using a magnet.

► Octahedral ZnFe2O4 nanocrystals with an average size of 10 nm were synthesized.
► The effects of sodium oleate led to the formation of ZnFe2O4 bound by {111} faces.
► The small size and octahedral morphology enhanced the photocatalytic degradation of RhB.
► Photocatalyst was superparamagnetic and could be recovered by the application of a magnet.