Preparation of hierarchical carbon/CoFe2O4/Co3Fe7 composite with super electromagnetic absorption by innovative ball-milling assisted chemical precipitation instead of traditional solvothermal method

To overcome the serious situation of electromagnetic pollution at present stage, herein the hierarchical carbon/CoFe2O4/Co3Fe7 composites were prepared via an innovative ball milling assistant chemical precipitation and subsequent annealing technique. By changing the solvent ratio of DW/DMF and the additive amount of milling balls, the micro-nano structures, electromagnetic parameters and response behavior of hybrids can be adjusted, in which the N-6 composite obtains a maximal RL of -42.70 dB at 16.42 GHz with the broadest EAB of 8.68 GHz for only 2.38 mm. Based on the well matched impedance within wide frequency region, the excellent attenuation properties of this composite generated from the strong dielectric polarizations, magnetic resonances, eddy current and structure-scattering effect could play roles to absorb incident electromagnetic wave. In short, this investigation offers an innovative route to synthesize the hierarchical carbon decorated with CoFe2O4 and Co3Fe7 nanoparticles for super electromagnetic absorption.& COPY; 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).