Preparation of magnetic flower-like carbon-matrix composites with efficient electromagnetic wave absorption properties by carbonization of MIL-101(Fe)

•Magnetic carbon-matrix composites were prepared by carbonization treatment of MIL-101(Fe).•The Fe3C/C and Fe3C/Fe/C products show efficient electromagnetic wave absorption properties.•A minimum RL value of −39.43 dB could be achieved at 14.00 GHz with the thickness of 2.00 mm.•The composites own flower-like structures formed by two-dimension flakes. As electromagnetic wave absorbers, carbon-matrix materials embedded with magnetic nanoparticles could meet both magnetic loss and dielectric loss requirement. In this work, magnetic Fe3C/C (denoted as FC-650) and Fe3C/Fe/C (denoted as FC-700) carbon-matrix composites were successfully fabricated via carbonization of Material Institute Lavoisier (MIL)-101(Fe). Particularly, both Fe3C/C and Fe3C/Fe/C owned flower-like structures formed by two-dimension flakes. Due to flower-like structures and components of the samples above, excellent electromagnetic wave absorption with dual-loss mechanism could be effectively realized. Fe3C/C possessed an optimal reflection loss of −39.43 dB at 14.00 GHz, measured with an absorption thickness of 2.00 mm. Moreover, it exhibited a broad effective bandwidth of 14.32 GHz (from 3.68 GHz to 18.00 GHz). The optimal reflection loss of Fe3C/Fe/C was up to −20.31 dB at 14.40 GHz corresponding to the absorption thickness of 2.00 mm. Multiple internal reflection, interfacial polarization, ferromagnetic resonance, interference cancelation and conduction loss might account for the absorption properties of the prepared magnetic carbon-matrix composites. This paper not only expands a new application aspect for MIL-101(Fe) as a precursor of magnetic materials, but also provides a simple approach to prepare flower-like electromagnetic wave absorbers.