Ultralight 3D cross-linked reinforced graphene@Fe3O4 composite aerogels for electromagnetic wave absorption

Graphene aerogels with three-dimensional (3D) hierarchical porous structures have attracted considerable attention as absorptive materials. Here, an enhanced 3D graphene oxide/carbon nanotube/epoxy resin aerogel (GCEA) was used as a template to successfully deposit Fe3O4 nanoparticles on the pore walls through in-situ chemical precipitation, resulting in a 3D composite aerogel absorber (rGCEA@Fe3O4) with both dielectric and magnetic loss properties. The rGCEA@Fe3O4 possesses excellent structural stability, conductive network, and evenly distributed magnetic particles. The rGCEA@Fe3O4 showed excellent electromagnetic wave (EMW) absorption performance, with the minimum reflection loss (RL) reaching -58.13 dB at a frequency of 12.08 GHz and a thickness of 2.5 mm. The effective bandwidth was maximized at 6.64 GHz when the thickness was 2.2 mm. The aerogel prepared in this study can be directly used as encapsulation and absorptive materials for precision instruments. This work provides a new approach for the development of 3D hierarchical absorptive composite materials.