Introducing graphite nanosheets to change the microscopic morphology of CoS nanoparticles to obtain ultra-thin and excellent electromagnetic wave absorption performance

Abstract

The composite material of metal sulfide and dielectric material has always been regarded as a research hotspot in the field of electromagnetic wave absorption. In this work, the cobalt sulfide (CoS) particles were successfully grown on the modified graphite nanosheets (GNs) by the two-step hydrothermal method to obtain excellent CoS/GNs EM wave absorption materials. SEM images show that after adding GNs, the morphology of CoS particles will change from micron-scale regular spheres to irregular nano-fragments which attached to the surface of GNs. The reason is that the binding sites on the surface of GNs will limit the growth of CoS particles. Fortunately, the introduction of GNs not only adjusted the impedance matching performance of CoS, but also perfectly combined the dielectric loss and magnetic loss mechanisms. EM analysis showed that the minimum reflection loss (RLmin) of CoS/GNs materials is −52 dB at an ultra-thin thickness of 1.1 mm, and the effective absorption bandwidth (EAB) is 3.7 GHz (14.3 GHz–18 GHz). Therefore, this ultra-thin nanocomposite material is expected to have broad market application prospects.