Desirable microwave absorption performance of ZnFe2O4@ZnO@rGO nanocomposites based on controllable permittivity and permeability

ZnO decorated ZnFe2O4 nanoparticles were synthesized and combined with reduced graphene oxide (rGO) to form ZnFe2O4@ZnO@rGO ternary hierarchical nanocomposites by a controllable method. The microstructure, morphology, and microwave absorption performance of the ZnFe2O4@ZnO@rGO nanocomposites were investigated in detail. The permittivity and permeability of the composites can be effectively regulated by controlling the content of ZnO and rGO to achieve a good impedance matching. Due to the synergistic effect of dielectric loss and magnetic loss, the ZnFe2O4@ZnO@rGO nanocomposites exhibited strong wave absorption and wide absorption bandwidth. The optimal reflection loss (RL) of the ZnFe2O4@ZnO@rGO nanocomposites reached -35.2 dB at 12.0 GHz with a thickness of 2.0 mm and the effective absorption bandwidth was 3.7 dB. The ZnFe2O4@ZnO@rGO hierarchical architecture produced lots of heterogeneous interfaces which made a significant contribution to the wave absorption performance. The combination of interfacial polarization, dipole polarization, and eddy current loss enhanced the microwave absorption capacity of the ZnFe2O4@ZnO@rGO system. This work provides a feasible approach for the design and preparation of wave absorption materials with tunable permittivity and permeability.