Abstract: Effective electromagnetic wave absorption is now possible thanks to the design of the dielectric-magnetic double loss mechanism and the rich heterogeneous structure. In this study, hollow carbon spheres with rich heterostructures were synthesized using an easy and effective in situ growing approach. In addition to improving impedance matching, the hollow structure also reduces material density and weight. By modifying the load, this system can alter the dielectric characteristics of MXene, which in turn affects the sample's ability to absorb electromagnetic waves. MXene and the carbon material create a thick conductive network during the whole electromagnetic wave absorption process, creating the ideal environment for conduction loss. The sample's ability to attenuate electromagnetic waves is further improved by the interfacial polarization that the rich heterogeneous structure can produce. Co-magnetic nanoparticle nanoparticles are the main source of magnetic loss. The MXene@Co/C-100-800 (MCC-100-800) exhibits excellent electromagnetic wave absorption performance under the synergy of multiple loss mechanisms, with the maximum effective absorption bandwidth (EAB_max) reaching 7.20 GHz and the minimum reflection loss (RL_min) being -53.99 dB at 2.10 mm. Finally, this work is guided by the coating engineering of MXene and provides new ideas for the rational design of heterostructures of nanomaterials.

Key words: Heterostructure, Dielectric-magnetic double loss, MXene, Hollow carbon sphere, Electromagnetic wave absorption