One-step construction of hierarchically porous Fe-N doped carbon aerogels for efficient electromagnetic shielding performance with high absorption efficiency

It is a daunting task to balance the electromagnetic interference (EMI) shielding performance and the electromagnetic wave (EMW) absorption for eliminating the secondary pollution of reflected EMWs. In this work, chitin, a promising candidate with intrinsic high content of N, was utilized as a precursor to fabricate Fe-N doped chitin-based carbon aerogels with hierarchically porous architecture by one-step carbonization process. The multiple effects of potassium ferrate were integrated, including the activation effect of potassium hydroxide to form nanosized pores, the catalytic graphitization of Fe-based compound to facilitate the graphitization of carbon skeleton, as well as in-situ introduction of well-dispersed magnetic nanoparticles. As a result, the as-prepared hierarchically porous Fe-N doped chitin-based carbon aerogels exhibited an impressive conductivity of as high as 90.5 S/m, a high EMI SE of 54 dB with a fascinating absorption coefficient of 0.89, demonstrating multiple synergistic shielding mechanisms of multiple reflection/scattering, conduction loss, interfacial/dipole polarization loss, as well as magnetic loss. The methodology proposed here is an efficient strategy for developing high-performance EMI shielding materials with multiple shielding mechanisms. The Fe-N doped chitin-based carbon aerogels are promising candidates to serve as highly efficient EMI shielding materials in the fields of electronics, telecommunication and aerospace.