▎ 摘　　要

Fe3O4 nanoparticle-graphene oxide (MGO) composites were prepared by chemically binding carboxylic acid-modified Fe3O4 nanoparticles to polyethylenimine-functionalized graphene oxide (GO). The structure, morphology, and magnetic properties of the composites were characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), and vibrating sample magnetometry (VSM). The results show that the Fe3O4 nanoparticle content in the MGO composites can be easily controlled by changing the ratio of Fe3O4 nanoparticles to GO in the reaction mixture. The MGO composites obtained are superparamagnetic with high saturation magnetization, which can potentially be applied in magnetic targeted drug delivery, gene transport, magnetic resonance imaging, bioseparation, and magnetic guided removal of aromatic contaminants in waste water and in other fields.