Hierarchical Porosities Strategy to Enhance the Absorbing Performance of Graphene Aerogels

Graphene aerogels ha shown fabulous capability in microwave absorption (MA) because of their high surface area, low density, and great chemical stability. To fully exploit its MA capability, the microstructural regulation of graphene aerogels should be carefully studied. Herein, 3D holey‐reduced graphene aerogels (3D‐HGAs) with hierarchical porosity structures composed of nanopores in the plane of graphene oxide (GO) sheets and macropores in aerogel for high‐performance absorbing materials are prepared. The efficient absorption bandwidth (EAB) of 3D‐HGA can reach 7.1 GHz and the minimum reflection loss is −36.4 dB, showing a significant increase contrasted with 3D‐reduced GO aerogels (3D‐RGA). Hierarchical porosity, interfacial polarization, multiple reflections, and matched impedance are all benefits of promoting MA performance. Consequently, the low filling content, low density, and special hierarchical porosity inspire the design of high‐performance radar absorption materials.