Feiyue Hu

Silicon carbide (SiC) aerogels represent an emerging class of multifunctional materials that integrate a three-dimensional (3D) porous architecture with the intrinsically superior physicochemical properties, exhibiting considerable promise for thermal insulation and electromagnetic wave (EMW) absorption under extreme environments. This review systematically summarizes recent advances in the fabrication strategies, structure-property relationships, and functional performance of SiC aerogels. For thermal insulation, the highly porous framework effectively suppresses solid-state heat conduction and gas convection, while the wide bandgap semiconducting nature of SiC enables efficient thermal radiation attenuation, collectively ensuring excellent insulation stability at elevated temperatures. SiC aerogels deliver broadband and strong absorption through a combination of moderate electrical conductivity, abundant interfacial polarization, optimized impedance matching, and multiple scattering within the 3D porous network with respect to EMW absorption. Moreover, recent studies demonstrate that synergistic enhancement of thermal insulation and EMW absorption can be achieved via multicomponent compositional engineering, hierarchical structural design, and advanced fabrication techniques, thereby accelerating the deployment of SiC aerogels in frontier applications including aerospace, defense systems, and thermal management for emerging energy technologies.

To meet the demands of maritime defense and transportation, next‐generation microwave absorption (MA) materials must combine efficient attenuation and corrosion resistance (CR). SiC nanofibers, with their moderate dielectric constant and chemical inertness, are ideal multifunctional coating fillers. However, their single‐component nature limits microwave attenuation, resulting in low efficiency and narrow bandwidth. Incorporating corrosion‐resistant components and employing heterointerface engineering offers a promising strategy to enhance polarization loss and synergistically improve CR. In this study, SiC nanofibers synthesized via chemical vapor deposition are used as precursors; SiO ₂ interlayers and nitrogen‐doped carbon shells are sequentially introduced to form multilayered core–shell nanofibers. Abundant heterointerfaces and defects effectively regulate impedance matching and introduce multiple loss mechanisms, including conduction, interfacial, and defect‐induced dipole polarization. The prepared SiC@SiO ₂ @C (SSC) nanofibers achieve a minimum reflection loss of −52.40 dB, a maximum effective absorption bandwidth of 7.68 GHz, and a maximum radar cross‐section reduction of 38.42 dB m ² , demonstrating excellent MA properties. Moreover, SSC/polyvinylidene fluoride (PVDF) composite coatings exhibit superior CR performance, with significantly enhanced corrosion potential and reduced current density compared to pure metal and PVDF coatings. This study underscores the synergistic effect of heterointerface engineering in enhancing both MA and CR for harsh environments.