Enhanced Microwave Absorption Properties of CeO2 Nanoparticles Supported on Reduced Graphene Oxide

Abstract

In this work, reduced graphene oxide/CeO2 nanocomposites (RGO/CeO2) with two different RGO contents were synthesized using a facile one-step hydrothermal method, and the microwave absorption properties of RGO/CeO2 were investigated for the first time. Morphology and structure analysis shows that the CeO2 nanoparticles are uniformly dispersed on the RGO sheets with average size of 15[Formula: see text]nm. The as-prepared RGO/CeO2 exhibits excellent microwave absorbability. An optimal reflection loss (RL) of [Formula: see text]32[Formula: see text]dB is found at 17[Formula: see text]GHz with a coating layer thickness of 1.5[Formula: see text]mm. The product with a coating layer thickness of only 2.0[Formula: see text]mm shows a bandwidth of 4.3[Formula: see text]GHz, corresponding to RL at [Formula: see text]10[Formula: see text]dB (90% of electromagnetic wave absorption). Compared with pristine RGO or pure CeO2 nanoparticles, the reported nanocomposites achieved both wider and stronger wave absorption in the frequency range of 2–18[Formula: see text]GHz. The enhanced microwave absorption properties are attributed to the conductive loss and dielectric loss mainly caused by the higher oxygen vacancy concentration of CeO2 in RGO/CeO2, which is demonstrated by X-ray photoelectron spectroscopy. Moreover, multiple interfacial polarizations occurring in the multi-interfaces between CeO2 and RGO sheets may be beneficial to microwave absorption. RGO/CeO2 could be used as an attractive candidate for the new type of microwave absorptive materials.