A series of magnetic nitrogen-doped graphene (MNG) composites were synthesized via a hydrothermal method and utilized in Methylene blue (MB) decolorization under visible light. The physical and chemical properties of the composites were characterized by powder X-ray diffraction (XRD), Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), UV-vis diffuse reflectance spectra (DRS) and BET. The results show that MNG (0.5) exhibits a remarkable photocatalytic performance for MB and the decolorization rate can be kept 85.4% even after three recycles, which also can be easily collected by an external magnet. The enhanced catalytic activity should be attributed to the improved photoadsorption properties and separation efficiency of photogenerated electron-hole pairs resulted from the manufacture of a Fe2O3/NGs heterojunction. (C) 2018 Published by Elsevier B.V. on behalf of Institution of Chemical Engineers.