Improved impedance matching by multi-componential metal-hybridized rGO toward high performance of microwave absorption

Microwave-absorbing materials with good microwave absorption performance are of great interest for military applications and human health, which is threatened by electromagnetic radiation pollution. Herein, the design and synthesis of multi-componential metal-hybridized graphene composites via freeze drying and pyrolysis of ferrocene hydrazone complex precursor are reported. Various magnetic nanoparticles are loaded on reduced graphene oxide (rGO) via controlling their pyrolysis temperature. The complex electromagnetic parameters of these hybrids are therefore regulated by the hybrid components. Among them, rGO hybridized by the sea-island-like Fe2O3/Fe3O4/FeNi3multi-componential metals shows a good balance of dielectric and magnetic constants. Thus, the improved impedance matching with free space brings about a superior electromagnetic wave absorption performance, especially on the effective absorption bandwidth. The minimum reflection loss (RL) of the hybrids is as low as −40.3 dB at 11 GHz with the RL bandwidth of −10 dB being 4.55 GHz (from 9.25 to 13.8 GHz).