文摘
To understand the principles and mechanisms of the graphene-based electromagnetic response composites, we prepare magnetic graphene–Fe3O4 (G–F) hybrid materials and study the electromagnetic properties in the frequency region of 2–18 GHz. The introduction of Fe3O4 nanoparticles is found to play a dominant role in the complex permittivity, resulting in changing the surface polarization and interfacial resistivity of the graphene-based fillers. These influences have been found to greatly impact the corresponding microwave absorption and electromagnetic shielding performance. Owing to the syngeneic effects of G and Fe3O4, the wax-based composites with G–F presented effective microwave absorption (<−10 dB) and sufficient electromagnetic shielding performance (>20 dB) in the investigated region. The associated mechanisms based on tuning the electromagnetic response of the graphene-based composites via the unique Fe3O4 interfaces have been intensively discussed, which promises great guidance in rationally designing and fabricating advanced graphene-based electromagnetic response materials.