Facile fabrication of Co-MOF/GNs derivatives as electromagnetic wave absorber with thin thickness for X and Ku bands

Abstract

The application of carbon matrix and magnetic composites as electromagnetic wave absorbing materials has attracted extensive attention. The Co-MOF/Graphite nanoflakes (GNs) derived microwave absorbing material supported by MOF structure was acquired via hydrothermal method and subsequent calcination treatment. The best reflection loss value of the sample obtained by pyrolysis at 600 °C is −43.62 dB at 15.84 GHz, simultaneously, the thickness is only 1.6 mm, and the effective absorption bandwidth (EAB) can reach 5.2 GHz (12.8–18 GHz). The Co-MOF/GNs derivatives possess a thinner absorbent thickness and a rather wide EAB value (mainly distributed in the X and Ku bands). Its absorbing bandwidth and thickness of absorbing agent are far superior to most MOF-derived absorbing materials. Its excellent electromagnetic wave absorption performance is chiefly attributed to multi-component dipole polarization, interface polarization from multiple interfaces, and multiple reflection and scattering effects of sandwich micro-structure with high porosity on electromagnetic waves. This paper provides a certain reference value for the design of lightweight and efficient radar absorbers suitable for X and KU bands, which can be applied to radar absorbing materials, multi-band and various applications.