Multiple pore-forming mechanisms towards crumpled porous Fe3O4/C composite microspheres for lightweight and high-efficient electromagnetic wave absorption

For high-performance electromagnetic wave (EMW) absorbers, designing inventive porous structures and developing multicomponent hybrid strategies remain challenging. Herein, crumpled porous Fe 3 O 4 /carbon composite microspheres (CMs/Fe) were synthesized via a multi-component pore-forming mechanism. By leveraging the rich nitrogen/oxygen functional groups and strong cross-linking properties of a monomer, namely triallyl isocyanurate (TAIC), the crumpled morphology, pore size, and nitrogen content of CMs/Fe were effectively regulated by adjusting the TAIC content. During carbonization, Fe 3 O 4 reduced to Fe particles, which catalyzed the formation of additional pore structures, increasing the specific surface area and further optimizing impedance matching. This is distinct from the previously reported Fe 3 O 4 /C composite. Additionally, the incorporation of magnetism into the carbon matrix enhanced the performance of the carbon material. Deionized water was used as the solvent throughout the synthesis process, making entire process ecofriendly and sustainable. Owing to electromagnetic synergistic attenuation, the CMs/Fe-2, with a low filling ratio of 16.7 %, exhibited a minimum reflection loss (RL min ) of −54.3 dB at an ultrathin thickness of 2.0 mm, with an effective absorption bandwidth (EAB) of 5.26 GHz. This work provides new insights into the fabrication of lightweight magnetic/carbon composite materials as the leading candidates for EMW absorption applications.