Synthesis and enhanced electromagnetic absorption properties of Co-doped CeO2/RGO nanocomposites

Co-doped CeO2/reduced graphene oxide (RGO) nanocomposites were prepared successfully by a simple solvothermal method using cobalt nitrate, cerium nitrate, and graphene oxide. The structure, micromorphology, material composition, and electromagnetic properties of the nanocomposites were investigated by X-ray Power diffraction, X-ray photoelectron spectroscope, transmission electron microscope, and vector network analyzer. The microwave absorption performance of nanocomposite in 2-18 GHz was calculated in accordance with transmission line theory. These results suggest that Co-doped CeO2/RGO composites do not influence the cubic fluorite structure of CeO2 and that Co-doped CeO2 nanoparticles were densely attached onto the RGO sheets (GSs). The Co-doped CeO2/RGO composites also enhanced microwave absorption properties owing to the synergetic effect between the Co-doped CeO2 nanoparticles and GSs and the unique structure of CeO2. When the added molar ratio of Co(NO3)2·6H2O and Ce(NO3)3·6H2O was 1:6, the composites attained the optimal microwave absorption of −53.66 dB at 6.4 GHz under the coating thickness of 3.5 mm. By contrast, frequency bandwidths below −10 and −20 dB were 4 and 1.28 GHz, respectively, under the coating thickness of 2.0 mm.