One-step ball-milling preparation of highly photocatalytic active CoFe₂O₄-reduced graphene oxide heterojunctions for organic dye removal

We prepared CoFe₂O₄-RGO (RGO: reduced graphene oxide) composites by ball-milling without using toxic chemical reagents and high-temperature heat treatment. The exfoliation and reduction of graphite oxide and anchoring of CoFe₂O₄ nanoparticles on graphene sheets were accomplished in one step. The microstructure of the heterophotocatalyst was characterized by X-ray diffraction, Fourier transform infrared, Raman and transmission electron microscopy methods. The photocatalyst exhibited desirable photocatalytic performance with excellent recycling stability for the degradation of methylene blue, rhodamine B and methyl orange under visible-light irradiation. In addition, the CoFe₂O₄-RGO photocatalyst can be easily separated by an external magnetic field. The simple and efficient one-step ball-milling strategy for preparing the photocatalysts is more applicable to industrial production.