In situ ZrC-reinforced SiBCN nanofibers with superior electromagnetic wave absorption performance

SiBCN ceramic nanofibers suffer from limited electrical conductivity and polarization, restricting their electromagnetic wave (EMW) absorption. Here, SiBCN/ZrC composite nanofibers were fabricated by electrospinning and in situ carbothermal reduction. Conductive ZrC nanocrystals and graphitic carbon enhanced charge transport, while heterogeneous interfaces among ZrC, β-SiC, graphitic carbon, and amorphous SiBCN promoted interfacial polarization. The optimized SiBCN/ZrC-4 nanofibers balanced dielectric attenuation and impedance matching, achieving a minimum reflection loss of −52.02 dB at 3.5 mm and an effective absorption bandwidth of 6.32 GHz at 2.0 mm. Their total effective absorption bandwidth reached 13.04 GHz over 1.5–5.0 mm, nearly covering the C, X, and Ku bands. Radar cross-section simulations further confirmed stable scattering suppression under normal and oblique incidence. This work demonstrates an effective phase and interface engineering strategy for broadband polymer-derived ceramic EMW absorbers.