Zeolitic imidazolate framework derived Fe-N/C for efficient microwave absorbers

Three main strategies for designing efficient microwave absorber includes the intrinsic dielectric/magnetic properties, the novel structure and the single atom doping. The Fe-N/C nanocomposites integrate the advantages of above three strategies into one system. In this work, the method for preparing Fe-N/C nanocomposite by calcining the FePc@ZIF-8 precursor under a flowing N-2 gas is described. Fe-N/C nanocomposites, displaying respectable dodecahedron-like morphology, have the merits of strong absorption ability, wide effective absorption bandwidth, thin thickness, and excellent microwave absorption efficiency, which are attributed to the synergistic effect of good electromagnetic loss capacity and proper impedance matching originating from intrinsic dielectric/magnetic properties, the novel structure and the single atoms (Fe and N) doping. Fe-N/C-24 composite delivers an optimal reflection loss of -30.98 dB, an effective absorption bandwidth of 5.04 GHz, the microwave absorption capacity of 87.61 dB GHz the absorption efficiency of 51.53 dB GHz/mm at 1.7 mm. (C) 2020 Elsevier B.V. All rights reserved.