Organic dyes removal using magnetic Fe3O4−nanographene platelets composite materials

In the present study, the applicability of magnetic Fe3O4-nanographene platelets (Fe3O4-NGP) composite with various concentrations of NGP was explored for the degradation of methylene blue under visible light irradiation. The magnetic, morphological, and structural characteristics of the as-prepared samples were characterized by vibrating sample magnetometry, X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, high resolution transmission electron microscope, Fourier transform infrared absorption spectroscopy, and Brunauer-Emmett-Teller (BET) surface area analysis. The experimental results showed that Fe3O4-NGP composites exhibited enhanced photocatalytic performance compared to pure Fe3O4 nanoparticles. The effect of NGP concentration (wt%) on the photocatalytic activity was also studied. It revealed that the photocatalytic performance was dependent on the concentration of NGP in the composite. The weight ratio of 5 wt% was proved to be the optimal ratio. Holes are the main active species in the degradation process due to the existence of NGP materials that act as electron acceptors and inhibit recombination of electrons and holes.