Sugar-gourd-like Co@carbon nanofibers for ultralightweight and outstanding electromagnetic wave absorber

To address increasing electromagnetic interference and pollution problems, this study proposes a component regulation strategy. Hollow magnetic microspheres derived from metal-organic frameworks (MOFs) were incorporated into carbon fibers (Co@CNFs) through electrospinning technology, forming a sugar-gourd-like heterostructure. This structure promotes the synergy between dielectric and magnetic losses. The full utilization of multi-component synergy and the well-designed heterogeneous interfaces enhances interfacial polarization and optimizes the balance between impedance and high loss. The hollow structure of magnetic microspheres facilitates multiple scattering of electromagnetic waves (EMW). Additionally, the change of heat treatment temperature offers a viable method to adjust the dielectric properties of composites. The results indicate that the Co@CNFs exhibit outstanding EMW attenuation capability, even at an ultralow filler loading of 3 wt%, achieving a reflection loss of −39.7 dB and an effective absorption bandwidth of 7.6 GHz. This study demonstrates the effectiveness of component regulation and offers a viable approach for lightweight, high-performance EMW absorption materials.