Mesoporous Hollow Carbon Spheres/Nanofibers Anchored With Conductive Bimetallic for Efficient Microwave Absorption

ABSTRACT To break electromagnetic wave absorption (EMA) tech's single‐attenuation bottleneck, enhancing multi‐wave absorption synergy in composites is key for microstructure design. This study uses mesoporous hollow carbon spheres to make metal nanospheres with cobalt, iron, and nickel nanoparticles, then encapsulates them via electrospinning into a unique carbon shell–cavity–core fiber structure. It is light, low‐density, and defect‐rich. The numerous heterogeneous interfaces embedded in carbon fiber endow it with excellent conductivity and high specific surface area. Based on this, the three‐dimensional conductive network further optimizes the transmission loss path of incident electromagnetic waves. Thanks to the effective cooperative of multiple absorption mechanisms, the NiFe 2 O 4 @PCHMs/CF composite material achieves an of −50.05 dB, and its maximum effective absorption bandwidth (EAB max ) reaches 7.68 GHz at a thickness of 7.2 mm. This outstanding performance far exceeds that of the NiCo@PCHMs/CF and CoFe 2 O 4 @PCHMs/CF fiber samples. This study not only explores the potential applications of electrospinning materials, but also provides new insights for the optimization design of electromagnetic wave (EMW) absorbing materials.