Solvothermal fabrication of CoS nanoparticles anchored on reduced graphene oxide for high-performance microwave absorption

•Uniform CoS nanomaterials dispersed on RGO sheets have been fabricated successfully.•CRs, initially used as EM absorbers, exhibit remarkable EM absorption performance.•A feasible strategy for synthesizing metal sulfides/RGO nanocomposites was provided.

CoS nanoparticles anchored on reduced graphene oxide sheets (CRs), synthesized via a facile solvothermal approach, are initially investigated as microwave absorbers. Such nanoarchitecture is significantly different from CoS microspheres (CMs) prepared in the absence of graphene oxide under similar preparation conditions. Moreover, the influence of loading concentration, layer thickness and CoS amount on the microwave absorption performance was systematically studied. In this study, with a thin filler loading of 20 wt% in paraffin matrix, CRs exhibited an effective microwave absorption bandwidth of 4.0 GHz at the thickness of 2.0 mm and an optimal reflection loss value of −54.2 dB at 6.8 GHz with the thicknesses of 4.0 mm. Furthermore, an effective absorption bandwidth (reflection loss below −10 dB) of 13.6 GHz (4.4-18.0 GHz) could be achieved via adjusting the thicknesses from 1.5 to 5.0 mm. The results indicated that CRs nanomaterials would be intriguing candidate as advanced microwave absorber. Meanwhile, we also provided a feasible strategy for construction of such metal-sulfides/RGO nanocomposites for a wide range of applications, such as Li-ion batteries, supercapacitors, and microwave absorbers.