High-efficiency and wide-bandwidth microwave absorbers based on MoS2-coated carbon fiber

Carbon fiber (CF) is a significant multifunction material, which is extensively used in aircraft because of its superb performance. However, its microwave absorption properties (MAPs) are seriously restricted as a result of the impedance mismatch issue. To address this issue, an efficient strategy is conducted by a series of CF@MoS2 and CF@MoS2@Fe3O4 composites that are fabricated by in-situ grown MoS2 nanosheets (MoS2-NS) and Fe3O4 nanoparticles (Fe3O4-NPs) on the surface of CF. The results of microwave absorption performance (MAP) reveal that the minimum reflection loss (RL) can reach -21.4 dB with a CF@MoS2 composite coating thickness of 3.8 mm; the effective attenuation bandwidth (RL < -10 dB, i.e., 90% microwave energy is attenuated) is up to 10.85 GHz (7.15-18.0 GHz). From a detailed analysis, it is observed impedance mismatch is the critical limiting factor for MAPs rather than attenuation. Furthermore, for CF@MoS2@Fe3O4, the MAP is strongly dependent on the level of coating of magnetic Fe3O4-NPs on the surface of CF@MoS2 composites. The mechanisms underlying the superb MAP and related phenomena are investigated, opening new directions for fabricating CF-based microwave absorbers with high efficiency and wide-bandwidth. Finally, the occurrence of multi-reflection phenomena of EM waves in absorbers are critically analyzed. (C) 2020 Elsevier Inc. All rights reserved.

Automated summary

This study addresses the challenge of impedance mismatch affecting the microwave absorption properties of carbon fiber by fabricating a series of CF@MoS2 and CF@MoS2@Fe3O4 composites, achieving promising microwave absorption performance. It is found that impedance mismatch is the critical limiting factor for MAPs.