Synthesis of Co/CoO@RGO composite for enhanced electromagnetic microwave absorption performance

Abstract

In this paper, the Co/CoO composite was prepared via polyol reduction method, and the Co/CoO was wrapped by reduced graphene oxide (RGO) synthesized with Hummers’ method. The crystal texture, element composition, micromorphology, magnetic properties, and electromagnetic absorption performance of the composite were tested. Compared with the single RGO or Co/CoO, the electromagnetic absorption performance of the Co/CoO@RGO composite has been greatly improved. The RLmin (minimum reflection loss) is − 56.56 dB, the effective absorption bandwidth (RL ≤ − 10 dB) is 5.86 GHz when the ratio of the compound to the paraffin is 1:1, and the thickness is 1.9 mm. The absorption properties of the Co/CoO@RGO composite are excellent, partly due to the synergistic effect of the magnetic and dielectric materials, and partly due to various electromagnetic wave loss mechanisms inside the sample, including the interface polarization between the two materials, Debye relaxation of various substances. Thus, the Co/CoO@RGO composite is a promising material in the field of microwave absorption.