Epoxy resin based composite filled with low-loading LRGO@AC and CoFe₂O₄ for excellent electromagnetic absorption performance

In this work, large-sized reduced graphene oxide@activated carbon (LRGO@AC) and CoFe₂O₄ were prepared by thermal reduction and solvothermal method. The epoxy resin based composites were successfully synthesized via a simple physical mixing way. Its complex permittivity, permeability, and reflection loss (RL) were characterized by using an Agilent N5234A vector network analyzer. The results showed that the LRGO@AC/CoFe₂O₄/epoxy composite presented excellent EM wave absorption performance at a 5 wt% loading of LRGO@AC/CoFe₂O₄. The minimum RL value reached − 42.70 dB at 11.24 GHz and the effective absorption bandwidth (RL <  − 10 dB) reached 5.45 GHz with a matching thickness of 3.0 mm. The excellent EM wave absorption performance was due to the unique 3D conductive network structure of LRGO which is conducive to the uniform dispersion of LRGO@AC and CoFe₂O₄ in the matrix, which facilitates the interaction of the filler in the epoxy resin and promotes the synergistic effect of electromagnetic loss. Moreover, the results of HFSS show that the radar cross section (RCS) can be reduced rapidly. Therefore, the LRGO@AC/CoFe₂O₄ would be a useful absorbing material.