Magnetic carbon fibers with hierarchical porous structure for efficient electromagnetic wave absorption and interference shielding

Hierarchical porous structure and electromagnetic (EM) synergy are two important factors in manipulating EM wave absorption and EM interference shielding. Inspired by this thought, herein, a series of magnetic carbon fibers with both hierarchical porous structure and synergistic effect are successfully fabricated by the electrospinning through adjusting the pyrolysis temperature and adding pore-forming agents. Results demonstrate that NiFe Prussian blue analogues derivatives are uniformly distributed in the interior of carbon fibers and induce magnetic loss, the carbonization of poly(methyl methacrylate) and β-cyclodextrin produce hierarchical micro-meso-macropores and the carbon fiber networks provide highly long-range conductive pathways. Benefiting from the cooperative advantages, the fabricated magnetic carbon fibers display high-efficient EM wave absorption and EMI shielding. The minimum reflection loss is −59.4 dB and the absorption bandwidth reaches as wide as 10.2 GHz. Furthermore, the absorption-dominated shielding effectiveness (SE) achieves 18.5 dB. This study provides a simple method in modulating porous structure and inspires a valuable guideline for designing strong-absorption EM interference shielding materials.