In situ growth and pyrolysis synthesis of super-hydrophobic graphene aerogels embedded with ultrafine β-Co nanocrystals for microwave absorption

High-performance, lightweight, and broadband microwave absorption materials have drawn significant research focus. Graphene aerogels may give us inspiration for the design of highly efficient synergistic microwave absorption materials due to their low density and adjustable dielectric properties along with tunable porosity, providing abundant active sites for supporting functional magnetic components. Herein, we report a facile chemical reduction-assembly route, followed by in situ thermal decomposition for the fabrication of super-hydrophobic magnetic graphene aerogels. Owing to the improved attenuation characteristic and the synergistic effect, the fabricated magnetic graphene aerogels exhibited greatly enhanced microwave absorption performance. The hybrids with only 4.25 wt% of functional fillers reached a minimum reflection loss value of −51.6 dB at 14.6 GHz with an absorber thickness of 2.4 mm and a maximum effective absorption bandwidth (EAB, below −10 dB) of 6.5 GHz. Compared with other reported graphene-based absorbers, such high-performance synergistic microwave absorbers that are super-hydrophobic and lightweight with low filler loading may rapidly increase the research interest for future practical applications.