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

Abstract

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.