Hierarchical CoFe/nitrogen-doped Carbon/CNFs composites via electrospinning and MOF conversion for electromagnetic wave absorption

The widespread use of electronic devices and telecommunication systems has led to increasingly severe electromagnetic pollution. To address this challenge, a hierarchically heterogeneous CoFe alloy/nitrogen-doped carbon/carbon nanofibers (CoFe/NC/CNFs) structure was prepared by combining CoFe metal-organic framework (MOF) precursors with electrospinning technology and subsequent pyrolysis. At a paraffin filling ratio of 10 wt% and a thickness of only 1.7 mm, the CoFe/NC/CNFs 700 composite yielded an optimal absorption performance, with a minimum reflection loss (RLmin) of −66.18 dB and an effective absorption bandwidth (EAB) of 5.5 GHz. This excellent performance originates from the synergistic effect of conduction loss from the CNF network, magnetic loss from the CoFe alloy, and interfacial polarization from abundant heterogeneous interfaces, which together optimize impedance matching. This work demonstrates a novel design strategy that integrates MOF derivation with electrospinning to construct high-performance EMW absorbers through multi-component cooperation.