▎ 摘　　要

The monodispersed ultrasmall Fe3O4 nanoparticles (NPs) have been anchored on reduced graphene oxide (rGO) nanosheets through a one-step method. Hybriding Fe3O4 particles with rGO sheets benefits adjusting the permittivity and permeability of the composite, balancing the dielectric loss and magnetic loss. The Fe3O4/rGO composite with a thickness of 3.0 mm exhibits an optimum absorption of - 71.86 dB at a low filler loading of 20 wt%, superior to most Fe3O4/graphene composites. The effective absorbing bandwidth covers 4.1 GHz. These results indicate that the Fe3O4/rGO composites prepared by facile synthesis can be ideal candidates as microwave absorbers with lightweight and excellent microwave absorption properties.