Hierarchically porous and multicomponent synergistic SiC/Fe3Si@rGO composite aerogel for electromagnetic wave absorption

SiC nanofiber aerogels show advantages such as high-temperature stability and tunable electromagnetic parameters in the field of electromagnetic wave (EMW) absorption. However, the intrinsically low electrical conductivity and single loss mechanism on these materials limit the strong and broadband absorption of EMWs. Herein, Fe3Si/SiC composite nanofibers were prepared via electrospinning followed by high-temperature pyrolysis. Subsequently, a hierarchically porous multicomponent synergistic SiC/Fe3Si@rGO composite aerogel was constructed by combining ice templating with graphene oxide incorporation. The composite aerogel shows a minimum reflection loss of −46.68 dB at a thickness of 3.0 mm, exhibiting effective absorption (reflection loss < −10 dB) across the entire C, X, and Ku bands (4–18 GHz) within a thickness range of 1.5–5 mm, which indicates its excellent broadband and strong-absorption performance. Further analyses reveal that the introduction of Fe3Si provides magnetic loss, whereas the graphene sheets not only form a three-dimensional conductive network, enhance interfacial polarization, and improve conductive loss, but also refine and enrich the pore structure. These features notably optimize impedance matching and promote multiple scattering and attenuation of EMWs. Thus, this study offers a new strategy for the development of lightweight, efficient, and broadband EMW-absorbing materials.