Growing MoO3-doped WO3 nanoflakes on rGO aerogel sheets towards superior microwave absorption

Nowadays, there is an urgent need for microwave absorbing materials with light weight, thin thickness, and strong absorbing ability to solve the problem of electromagnetic radiation. In this study, we report a novel high-performance aerogel absorber by growing MoO3-doped WO3 nanoflakes on reduced graphene oxide (rGO) sheets. The resultant rGO-Mo-WO3 aerogel displays a low density (similar to 75 mg/cm(3)) and unique hierarchical architectures including 3D porous microstructures, 2D rGO skeleton, and binary transition metal oxide of Mo-WO3 nanoflakes, thus leading to excellent microwave absorption performances. Typically, rGO-Mo-WO3 aerogel exhibits an ultra-strong reflection loss (RL) of -61.8 dB with a thin coating thickness of 1.54 mm. And a wide effective absorption bandwidth of 6.24 GHz can be achieved at a low filler loading of 8 wt%, much superior to previous ones. The synergistic effect of moderate polarization relaxation loss and weak conduction loss together with the porous microstructure for the aerogel result in the suitable impedance matching and strong microwave attenuation ability. This work may demonstrate a promising method to fabricate hierarchically nanostructured absorbers with the advantages of light weight, ultra-strong microwave absorption, and thin coating thickness. (C) 2021 Elsevier Ltd. All rights reserved.