Scalable Green Method to Fabricate Magnetically Separable NiFe₂O₄-Reduced Graphene Oxide Nanocomposites with Enhanced Photocatalytic Performance Driven by Visible Light

A reduced graphene oxide (RGO)-supported nickel ferrite (NiFe₂O₄) photocatalyst was prepared by a simple mechanical ball-milling method. No additional solvents, toxic chemical reductants, or ultrasonic or high-temperature heat treatments were needed. The exfoliation and reduction of graphite oxide (GO) and the in situ anchoring of NiFe₂O₄ nanoparticles on graphene sheets were fulfilled simultaneously under the strong shear force. The structure characterization shows that the NiFe₂O₄ nanoparticles were uniformly dispersed on RGO sheets. Amazingly, after coupling with an appropriate amount of RGO, the photocatalytically inert NiFe₂O₄ exhibited superior photodegradation performance and recycling stability for the degradation of organic pollutant under visible-light irradiation at room temperature. It suggested that the synergistic effect between RGO and NiFe₂O₄ improved the photocatalytic performance of the composite. Moreover, the NiFe₂O₄-RGO is magnetically separable for recycling. Hopefully, this work could shed light on the environment-friendly large-scale production of graphene-based composites through the efficient ball-milling method.