Design and synthesis of core-shell structure 3D-graphene/Fe3O4@N-C composite derived from Fe-MOF as lightweight microwave absorber

To improve the microwave absorption performances of Fe3O4@N-C composite derived from Fe-MOF, 3D-graphene particles have been successfully dotted on the surface of Fe3O4@N-C composite through pyrolyzing 3D-graphene/Fe-MOF composites. Moreover, it is obvious that the electromagnetic parameters of the composites can be effectively adjusted by controlling the addition of 3D-graphene. Consequently, the optimal composite displays outstanding microwave absorption performances. The value of maximum reflection loss achieves −57.53 dB at 10.72 GHz with the effective absorption bandwidth of 3.92 GHz (9.18–13.10 GHz) at 2.30 mm matching thickness. In addition, the maximum effective absorption bandwidth with the value of 5.62 GHz (12.38–18.00 GHz) can be achieved at 1.81 mm matching thickness, which almost covers the whole Ku band. This work is expected to provide a reference for the mass preparation of new lightweight microwave absorption composites.