Multi-interfacial Co@CoNx@C(N) nanocapsules with nitrogen substitutions in graphitic shells for improving microwave absorption properties

Integrating multiple components with heterogeneous interfaces has been widely proven effective for optimizing the microwave absorption properties of composites. We herein report on an arc-discharging strategy to synthesize the onion-like Co@CoNx@C(N) nanocomposite with dual core@shell heterogeneous interfaces. The graphitic carbon shells are in-situ functionalized by nitrogen substitutions, resulting in the formation of pyridinic, pyrrolic and graphitic nitrogen substitutions. Such a structural configuration contributes to a significant enhancement in dielectric loss capacity, presenting three main attenuation peaks at the frequencies of 6.6 GHz, 13.5 GHz and 17.1 GHz, respectively. The Co@CoNx@C(N) nanocomposite simultaneously possesses on the synergistic effect of heterogeneous interfaces and the atomic-scale substitutions in a nanoscale system and thus has important implications in designing novel microwave absorption materials.