Oxygen vacancies regulated microwave absorption properties of reduced graphene oxide/multi-walled carbon nanotubes/cerium oxide ternary nanocomposite

Herein, reduced graphene oxide/multi-walled carbon nanotubes/cerium oxide (RGO/MWCNTs/CeO2) ternary nanocomposite was prepared by a facile one-pot hydrothermal route. Micromorphology observations revealed that RGO was wrapped by MWCNTs and numerously cubic-like CeO2 nanoparticles were uniformly loaded on the crumpled surfaces of thinly flake-like RGO and MWCNTs in the ternary nanocomposite. Moreover, the influence of addition of RGO and MWCNTs on the electromagnetic parameters and microwave absorption properties of RGO/MWCNTs/CeO2 nanocomposite was systematically investigated. It was found that the as-prepared ternary nanocomposite exhibited notably enhanced microwave absorption performance compared with RGO/CeO2 binary nanocomposite, MWCNTs/CeO2 binary nanocomposite and pure CeO2 nanoparticles. Remarkably, the obtained ternary nanocomposite displayed the minimum reflection loss (RL) of -59.3 dB in the C-band with a matching thickness of 4.5 mm and effective absorption bandwidth (EAB, RL < -10 dB) of 3.2 GHz with an ultrathin thickness of merely 1.5 mm. Furthermore, the EAB could reach 13.8 GHz (86.3% of 2-18 GHz) by facilely modulating the matching thicknesses from 1.5 to 5 mm. The possible microwave absorption mechanisms of as-prepared nanocomposites were carefully explored and further proposed. Therefore, our results could shed light on designing and fabricating graphene-based hybrid nanocomposites as high-performance microwave absorbers. (C) 2019 Elsevier B.V. All rights reserved.