Construction of MIL-88C/CuCo₂S₄-derived bamboo-like carbon nanotubes/carbon nanofiber aerogels for high-efficiency microwave absorption and thermal insulation performances

Multifunctional carbon aerogels have garnered significant attention due to their promising applications in thermal insulation and electromagnetic wave (EMW) absorption. In this study, MIL-88C/CuCo₂S₄ composite powders were self-assembled and anchored onto the aerogel framework, followed by the deposition of carbon nanotubes (CNTs) via catalytic chemical vapor deposition, yielding MIL-88C/CuCo₂S₄-derived bamboo-like CNTs/carbon nanofiber aerogels (FCC@CC series). By modulating component loading ratios, the formation of a three-dimensional conduction network, the presence of heterogeneous interfaces, enhanced magnetic loss, and engineered defects synergistically optimized dielectric and magnetic loss. This adjustment improved the impedance matching of the composite carbon aerogel, resulting in exceptional EMW absorption performance. The FCC@CC2 sample achieved a minimum reflection loss of −71.15 dB and an effective absorption bandwidth of 6.10 GHz. CST simulations further demonstrated the practical applicability, showing a maximum radar cross-section reduction of 34.92 dB·m². Power loss density and electric field distribution analyses corroborated the superior electromagnetic attenuation capabilities of the FCC@CC. This work establishes a methodology for developing lightweight multifunctional aerogels with pressure resistance, thermal insulation, and infrared stealth properties, providing a novel strategy for the fabrication of microwave absorbers for use under complex conditions.