Highly enhanced electromagnetic wave absorption bandwidth based on reduced graphene oxide-Fe aerogel composites

In order to achieve large electromagnetic (EM) wave absorption bandwidth, reduced graphene oxide (rGO)-Fe aerogel composites were fabricated by hydrothermal method and subsequently heat treated under reduced atmosphere. The effects of Fe²⁺ content on the microstructures and EM wave absorbing properties of the aerogel composites have been studied. The Fe nanoparticles in the size of 50-100 nm deposited on the graphene sheets were responsible for the improvement in magnetic properties of the rGO aerogel composites. The absorbing performance could be tailored by varying the concentrations of Fe²⁺, and when the content of Fe²⁺ was 0.125 mmol, the absorption bandwidth reached 6.1 GHz with the thickness of 2.7 mm. The broad absorption bandwidth of rGO-Fe aerogel composites was ascribed to the synergistic effect of magnetic Fe nanoparticles, high dielectric loss of rGO, and the unique porous aerogel microstructures.