A α-Fe2O3/rGO magnetic photocatalyst: Enhanced photocatalytic performance regulated by magnetic field

The magnetic photocatalyst alpha-Fe2O3/reduced graphene oxide (rGO) was constructed to enhance the photocatalytic efficiency by the magnetic field. The results of X-ray diffraction spectrometer (XRD), Raman and high resolution transmission electron microscope (HRTEM) indicated the successful preparation of the alpha-Fe2O3/rGO composite photocatalyst, and the enhanced optical absorption for visible light after the growth of rGO was also demonstrated by UV-vis spectrophotometer. The introduction of rGO enhances the transfer of photogenerated carriers, and the interface effect between alpha-Fe2O3 and rGO makes the photocatalyst having a stronger magnetization intensity and larger negative magnetoresistance (MR) than pure alpha-Fe2O3, thus the introduction of magnetic field can further improve the transfer of carriers. When the mass ratio of alpha-Fe2O3 and rGO was 10:1, the alpha-Fe2O3/rGO composite photocatalyst could reach the best photocatalytic performance, i.e. degrading 60% of Congo red (CR) after visible light irradiation of 30 min, and its photocatalytic performance was much better than that of other photocatalysts with different rGO concentration. With the magnetic field of 1000 Oe, the alpha-Fe2O3/rGO (10:1) composite photocatalyst could degrade 87% CR under visible light which was higher than that without the magnetic field, indicating the efficient magnetic effect on the photocatalytic reaction of alpha-Fe2O3/rGO (10:1). These results will provide a new perspective for developing efficient photocatalyst, and make it possible to further improve the performance of existing photocatalysts. (C) 2020 Elsevier B.V. All rights reserved.