Enhanced electromagnetic wave absorption performance of rGO composites modified with atomically dispersed bi-metalic znic/cobalt sites

An effective strategy for improving microwave absorbing performance was proposed in atomically dispersed bimetallic carbon-based composite materials. The atomically dispersed ZnCo-NC@rGO composites were synthesized though metal-mediated formamide (FA) condensation and carbonization. By adjusting the Co/Zn sites loading, the electromagnetic parameters and absorption performance could be effectively optimized. With the Co/Zn ratio of around 0.01, the minimum reflection loss (RL_min) reached − 26.63 dB at absorbing thickness of 1.50 mm, and the maximum effective absorption bandwidth (EAB, RL <  − 10 dB) was up to 4.52 GHz (12.78–17.30 GHz) at absorbing thickness of 1.60 mm, covering almost the Ku band. A stronger RL_min of − 59.63 dB was obtained with a thickness of 4.70 mm. Different loading of atomically dispersed metal sites induces variations in metal center and ligand structure. This endows ZnCo-NC@rGO excellent impedance matching and synergistic electromagnetic loss effects. In addition, the maximum radar cross section (RCS) reduction value was up to 26.94 dB m² at a scattering angle of 0°. This study points out a feasible path for the fabrication of carbon-based ultralight synergistic absorbers.