Heterostructures of FeCoSe@MoS2 on Reduced Graphene Oxide Aerogels for Electromagnetic Wave Absorption at Low Frequency and Thermal Insulation.

The development of lightweight, high-efficiency, and tunable electromagnetic wave (EMW) absorption materials is crucial in mitigating electromagnetic pollution. However, conventional powdered absorbers generally suffer from unsustainability and limited functionality. In this regard, FeCoSe@MoS2/reduced graphene oxide (rGO) aerogels with multiscale heterostructures were successfully constructed through the integration of FeCoSe@MoS2 and GO via solvothermal and subsequent directional freeze-drying strategy. The interconnected porous architecture and plentiful heterointerfaces induced by the rational multicomponent composition benefit to optimize impedance matching and enrich EMW loss behaviors. The EMW absorption performance could be effectively modulated by adjusting the component composition. The FeCoSe@MoS2/rGO aerogel with component optimization realizes a minimum reflection loss (RLmin) of -55.21 dB and impressive effective absorption bandwidth (EAB) of 6.74 GHz (11.26-18.0 GHz). Notably, the resultant aerogels reveal significantly low-frequency EMW response. An RLmin of -43.83 dB at 7.24 GHz at a matching thickness of 4.09 mm and a wide EAB of 2.63 GHz (5.31-7.94 GHz) under a matching thickness of 4.55 mm are achieved in the C band. The low-frequency EAB could reach up to 3.04 GHz (4.96-8 GHz) by adjusting the matching thickness. The EAB of the resultant aerogel could reach up to 13.04 GHz by facilely regulating the matching thicknesses, which almost completely cover the C, X, and Ku bands. The radar cross-section simulation intuitively verifies the effectiveness of the resultant aerogels used for advanced stealth materials. Additionally, the fabricated aerogel reveals brilliant thermal insulation property, satisfying the multifunctional requirements. This work offers innovative insights for constructing multifunctional EMW absorption aerogels via structural design and component optimization.