One-Step Combustion Synthesis of Magnetic Fe2O3/TiO2/Graphene Hybrids and Their Visible-Light-Driven Photodegradation of Methylene Blue

The visible-light responsive magnetic Fe2O3/TiO2/graphene (GTF) hybrid photocatalysts have been synthesized by a simple one-step combustion method. The structures, morphologies, and magnetic properties were characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, ultraviolet-visible diffuse reflectance, photoluminescence, and vibrating sample magnetometry. As-obtained GTF hybrids are composed of graphene, TiO2, alpha- and gamma-Fe2O3. The morphologies of GTF hybrids show that Fe2O3 and TiO2 nanoparticles were anchored onto the surface of graphene sheets. Moreover, as-synthesized GTF photocatalysts could be easily separated from the treated water under an external magnetic field. Compared with pure TiO2 and graphene/TiO2 hybrids, GTF hybrids exhibit wider visible-light absorption range and reduced charge recombination. Visible-light photodegradation results show that GTF hybrids possess improved visible-light photocatalytic performance than other samples, and no obvious deactivation was observed in cycle experiments. The mechanism of the improved photocatalytic activity, aroused from the synergistic effect of TiO2, Fe2O3, and graphene, was discussed in detail.