Facile preparation of C/MnO/Co nanocomposite fibers for High-Performance microwave absorption

The C/MnO/Co nanocomposite fibers were prepared via a facile electrospinning and subsequent carbonization process. Co acting as the magnetic nanoparticles and MnO nanoparticles serving as impedance modulator were introduced, effectively inhibiting the agglomeration of carbon fibers during annealing. This optimizes the microstructure and significantly improves the microwave absorption performance of the nanocomposites with diameters of 250–350 nm and rough surface morphologies . The nanocomposite fibers with equal MnO and Co molar contents exhibited the minimum reflection loss of − 71.7 dB at a frequency of 14.1 GHz and an absorber thickness of 2.3 mm, and the effective absorption bandwidth reached at 6.3 GHz at a thickness of 2.6 mm. The high microwave absorption performance can be attributed to the synergistic coactions of conduction loss, magnetic loss, interfacial polarization, and multiple scatterings derived from the rational design of the constituents and microstructure of the nanocomposites.