Multidimensional CoS2/C/MXene nanofiber heterostructures with synergistic magnetic-dielectric coupling for ultra-strong and broadband microwave absorption

Designing lightweight microwave absorbers that simultaneously achieve strong attenuation and broad bandwidth remains a major challenge. Here, we report a multidimensional CoS 2 /C/MXene heterostructure constructed through electrospinning and in-situ sulfidation, which integrates 0D CoS 2 nanoparticles, 2D MXene nanosheets, and a 1D conductive carbon-fiber network. This architecture generates abundant heterogeneous interfaces and continuous electron pathways, enabling synergistic magnetic-dielectric coupling and optimized impedance matching. The resulting composite achieves a minimum reflection loss of ‒70.86 dB at 10.6 GHz and an effective absorption bandwidth of 4.64 GHz at a low filler loading of 3 wt%. DFT calculations reveal significant interfacial charge transfer and built-in electric field formation, corroborating the enhanced polarization and conduction losses. Moreover, the composite exhibits excellent thermal stability, corrosion resistance, and mechanical flexibility. This work demonstrates an efficient strategy for constructing high-performance, low-density microwave absorbers through multidimensional heterostructure engineering.