▎ 摘　　要

Background: This study aims at proposing a facile method to prepare rGO/Fe3O4 composite film with adjusted magnetic properties and electronic conductivity. Methods: Colloidal solution of graphene oxide (GO)/Fe3O4 nanoparticles (F-NPs) with a size in the range of 20-80 nm were prepared by a solution-blending method and heated step-by-step from room temperature to 60 degrees C, 120 degrees and 160 degrees C for 12 hours, respectively, to obtain a reduced graphene oxide (rGO)/F-NP composite film. The structure, morphology, components, magnetic properties and electrical conductivity of the composite films were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, superconducting quantum interference devices and 4-probe instrument. Results: The results indicated that the F-NPs were uniformly distributed on the graphene film, and the composite exhibited good ferromagnetic properties and conductivity, which could be adjusted easily via different loadings of F-NPs. A high content of F-NPs (200 mg) led to a strong saturation magnetization of 63.6 emu.g(-1), with a coercivity of about 104.9 oersted (Oe). Whereas a high conductivity of 6.5 S.m(-1) was obtained at low amounts of F-NPs (40 mg). Notably, rGO/Fe3O4 composite film fabricated by this simple method is widely used in various fields including magnetoelectronics, electrochemical energy conversion and storage, and magnetic nanodevices and others. Conclusions: A graphene-based film deposited by Fe3O4 nanoparticles with controllable loadings has been fabricated by a step-by-step heating treatment of GO/Fe3O4 colloidal solution.