Pore modulation and heterointerface engineering of superhydrophobic Fe₂P@NP-PCNFs for broadband microwave absorption, radar and infrared compatible stealth

The widespread use of electromagnetic waves (EMWs) in defense and communications has caused serious electromagnetic interference, environmental pollution, and information leakage, driving the demand for high-performance microwave absorbers. However, the development of lightweight microwave absorbers with excellent impedance matching, strong attenuation, and ultra-wide effective absorption bandwidth (EAB) remains challenging. In this work, N/P co-doped porous carbon nanofibers (CNFs) embedded with in-situ grown Fe₂P nanoparticles were fabricated via electrospinning. By regulating the pore-forming agent content, the relationship between microstructure, electromagnetic parameters, and microwave absorption performance was investigated. At a pore-forming agent loading of 20 wt%, the sample exhibits a minimum reflection loss of −66.9 dB at 2.85 mm and EAB_max of 7.68 GHz at 2.95 mm. Furthermore, S20 exhibits a remarkably low filler content of only 4 wt%, attributed to enhanced polarization effects from Fe₂P NPs and N/P doping, coupled with impedance matching through optimized porous structure. In addition, S20 demonstrates excellent radar/infrared compatible stealth, high thermal stability, strong hydrophobicity (water contact angle of 134.3°), and corrosion resistance. This study proposes a viable strategy for designing lightweight, highly efficient microwave absorbers with good environmental adaptability, demonstrating potential practical application value.