Self-assembled multi-layered hexagonal-like MWCNTs/MnF2/CoO nanocomposite with enhanced electromagnetic wave absorption

The dielectric/magnetic synergistic component is an important part of electromagnetic wave (EMW) absorber to deal with electromagnetic pollution. In this work, multi- layered hexagonal-like MWCNTs/ MnF2/CoO composite is prepared via one-step hydrothermal and annealing process. Multi-walled carbon nanotubes (MWCNTs) adjust dielectric loss as well as CoO endows the composite with magnetic loss. As expected, the minimum reflection loss value is -64.73 dB with the matching thickness of 2.1 mm at 14.08 GHz, the effective absorption band is 6.64 GHz at 2.0 mm, when the content of MWCNTs is 30 mg. The excellent performance results from unique geometry and multiple attenuation mechanisms. The hollow structure helps obtain the appropriate impedance matching of further increasing scattering and reflection of incident waves within materials. Besides, heterogeneous interface between MnF2/CoO and MWCNTs generates interfacial polarization. More importantly, MWCNTs and CoO supply dielectric/ magnetic loss. The results show that MWCNTs/MnF2/CoO composite is a potential absorber and this research provides a novel method to prepare EMW absorbing materials. (C) 2021 Elsevier Ltd. All rights reserved.