Lightweight and highly efficient electromagnetic wave-absorbing of 3D CNTs/GNS@CoFe₂O₄ ternary composite aerogels

A novel 3D ternary composite aerogel composed of carbon nanotubes (CNT) and graphene nanosheets (GNS)@CoFe₂O₄ nanohybrids was synthesized via a solution mixing and followed by freeze drying process. Uniform 3D porous structure and interconnected network with dense interlinked CNT throughout the cell backbones endowed the prepared ternary composite aerogel with excellent microwave absorbability and lightweight. The composite aerogel with 3.0 mm thickness exhibits a maximum absorption of 29.1 dB at 10.34 GHz and in particular, displays a broad bandwidth (entire X-band) corresponding to reflection loss below at −5 dB. The synergetic effect of conductive CNT and magnetic GNS@CoFe₂O₄ nanoparticles provided high electromagnetic loss by eddy current in the 3D porous framework due to the improvement of the impedance match characteristics, resulting in strong absorption and weak reflection. This work possibly helps to design and prepare lightweight and high performance electromagnetic wave absorption materials based on 3D aerogel.