Synergistic Optimization of Pore and Conductive Network of Short-Cut Graphene Porous Fibers for Lightweight Broadband Electromagnetic Wave Absorption.

Graphene possesses high carrier mobility and structural tunability, but achieving effective electromagnetic wave (EMW) absorption with single-component graphene remains challenging due to the inherent trade-offs among filler loading, impedance matching, and attenuation intensity. Structural engineering of graphene has been proved to be an effective strategy to address this challenge. In this study, a series of short-cut graphene porous fibers (SCGPF) is fabricated through wet-spinning and freeze-drying, and regulating the pore size of SCGPFs to achieve precision control of electromagnetic parameters. The porous structure facilitates the formation of continuous 3D conductive networks among graphene sheets, effectively extending EMW transmission paths and improving impedance matching. Optimized pores enhance the polarization response at the pore edges, SCGPF-30 achieves a minimum reflection loss (RLmin) of -62.31 dB at 2 wt%. The formation of a large-scale 3D network further amplifies conduction loss at a low filler loading, SCGPF-30-3 reaches a maximum effective absorption bandwidth (EABmax) of 7.61 GHz (10.39-18 GHz) at only 1 wt%. These results demonstrate that synergistic optimization of pore size and conductive network in graphene significantly enhances EMW absorption under an ultralow filler loading, offering a promising strategy for developing high-performance graphene-based electromagnetic protection materials.