Ternary heterogeneous 0D@1D/2D CoFe₂O₄@SWCNT/rGO composite aerogels with a hierarchical structure for high-efficient electromagnetic wave absorption and thermal insulation

To mitigate the escalating electromagnetic wave (EMW) radiation pollution, the development of lightweight multifunctional graphene-based EMW absorbers has become a pivotal technological breakthrough. Research has demonstrated that multidimensional hierarchical structures offer great potential for creating multifunctional EMW absorbers. In this study, a three-dimensional (3D) lightweight composite aerogel composed of multidimensional nanomaterials was constructed by hydrothermal self-assembly combined with freeze-drying technique. The magnetoelectrically integrated 0D@1D CoFe₂O₄@SWCNT nanomaterials not only restricted the aggregation of CoFe₂O₄ nanoparticles, but also created multiple heterogeneous interfaces. The excellent synergy between the magnetic CoFe₂O₄@SWCNT and the porous structure of reduced graphene oxide (rGO) aerogel not only optimizes impedance matching but also establishes a magnetic-dielectric cooperative system that integrates multiple loss mechanisms, including enhanced multiple reflections, interfacial polarization, dipole polarization, conduction loss, and magnetic loss. Remarkably, the material attains a minimum reflection loss (RL_min) of −65.5 dB at 2.35 mm, alongside a broad effective absorption bandwidth (EAB) of 7.2 GHz at 2.45 mm. Furthermore, the prepared aerogel material also shows outstanding compressibility, excellent thermal insulation performance, and significant radar stealth capability, offering valuable perspectives for the design and optimization of EMW absorbers. The impressive performance characteristics of this material suggest that it holds promising potential for diverse applications in areas such as electromagnetic protection and radar stealth technologies.