▎ 摘　　要

In this work, reduced graphene oxide/CeO2 nanocomposites (RGO/CeO2) with two diffrerent 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 nm. The as-prepared RGO/CeO2 exhibits excellent microwave absorbability. An optimal reflection loss (RL) of -32 dB is found at 17 GHz with a coating layer thickness of 1.5 mm. The product with a coating layer thickness of only 2.0mm shows a bandwidth of 4.3 GHz, corresponding to RL at -10 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 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.