Flexible electrospun carbon nanofiber embedded with TiO2/FeNi as efficient microwave absorber

With the rapid development of communications, the electromagnetic environment we live in has been ignored, so absorbing materials have attracted attention in daily life and even national strategic fields. Flexible TiO₂/FeNi/C nanofiber membranes have been prepared through electrospinning, stabilization, and carbonization processes in this study. The unique three-dimensional network structure of nanofibers provides a large specific surface area and porous architecture, facilitating multiple scattering and interface polarization of electromagnetic waves, while the incorporation of TiO₂ and FeNi nanoparticles creates abundant heterogeneous interfaces, enhancing interfacial polarization and magnetic loss mechanisms. The electromagnetic wave absorption performance and electromagnetic parameters of the absorber in the frequency range of 1–18 GHz were studied. By adjusting the content of dielectric components and magnetic components, the impedance matching and electromagnetic wave absorption performance of TiO₂/FeNi/C have been improved. This optimization achieves a synergistic effect between dielectric loss (from conductive carbon networks and interfacial polarization) and magnetic loss (from natural resonance and exchange resonance of FeNi nanoparticles), significantly enhancing the attenuation of electromagnetic energy. At a thickness of 2.4 mm, the minimum reflection loss reaches −43.77 dB, and the comprehensive absorption bandwidth reaches 9.9 GHz. Owing to multiple loss mechanisms, nanosized effects, and optimized impedance matching between FeNi nanoparticles and CNFs, this lightweight and flexible TiO₂/FeNi/C nanofiber composite exhibits promising application prospects as an electromagnetic wave absorber.