“Point-line-plane” three-dimensional synergistic engineering in MoS₂/CoFe₂O₄-decorated flexible carbon nanofiber scaffold: A dual-functional film for integrated microwave absorption and thermal conductivity

As a representative transition metal dichalcogenide (TMD), MoS₂ exhibits a tunable bandgap, facile defect generation, controllable electrical conductivity, and high stability, positioning it as a promising dielectric material. However, its limited single-cycle dielectric loss capacity and impedance mismatch hinder its standalone microwave absorption performance. To address these limitations, compositing MoS₂ with magnetic components has been demonstrated as a viable strategy to optimize impedance matching and enhance absorption efficiency. This study innovatively developed a sandwich-structured composite film featuring polyacrylonitrile-derived carbon nanofibers (CNF) as flexible scaffolds, synergistically integrated with magnetic CoFe₂O₄ nanoparticles and dielectric MoS₂ nanosheets. Through electrospinning combined with pressure-assisted thermal molding processes, precise regulation of the CNF-(MoS₂/CoFe₂O₄) (CMC) heterointerfaces was achieved. The CMC exhibits superior microwave absorption through multiple loss mechanisms. Two-dimensional (2D) MoS₂ nanosheets facilitate polarization relaxation and dielectric loss, while nano-sized CoFe₂O₄ particles induce eddy current loss. Additionally, the high-aspect-ratio CNF constructs a three-dimensional (3D) conductive network that enhances conduction loss. Moreover, the uneven charge distribution at the heterogeneous interface induces polarization relaxation losses. Experimental results indicate that the optimized CMC sample achieves a minimum reflection loss (RL_min) of −45.6 dB at 14.2 GHz, with a matching thickness of 3.0 mm. This sample also exhibits an effective absorption bandwidth (EAB) of 7.8 GHz (ranging from 10.2 to 18 GHz) and a thermal conductivity of 0.163 W/(m·K). This research introduces a novel thin-film material design paradigm for the synergistic optimization of electromagnetic protection and thermal management in microelectronics. Furthermore, the layered composite strategy paves the way for the development of multifunctional microwave absorption materials.