ZIF‐67‐Derived Co@Carbon Polyhedra Anchored on Reduced Graphene Oxide with Multiple Attenuation Abilities for Full X‐ and Ku‐Band Microwave Absorption

Abstract

High‐performance microwave absorption (MA) materials are attracting growing attention to solve the expanded electromagnetic interference problems. Herein, zeolitic imidazolate organic frameworks (MOF)‐67 (ZIF‐67) are grown in situ on the sheet of graphene oxide (GO) through the coordination of Co2+ with oxygen functional groups. Through carbonization in an inert atmosphere, Co@carbon polyhedra (Co@CP)‐decorated reduced GO composites (Co@CP‐rGO) with a large number of heterogeneous interfaces are successfully obtained. The composites demonstrate excellent MA performance. With a filler loading of 10 wt%, the optimal minimum reflection loss (RL) of the composite can reach −54.6 dB. More importantly, the composites with thickness of 3.5 and 2.5 mm show the effective absorption bandwidth (RL < −10 dB) of 4.75 GHz (8.18–12.93 GHz) and 6.56 GHz (11.44–18 GHz), fully covering the X‐ and Ku‐band. It is proposed that the synergistic effect of multiple dielectric loss, magnetic loss, reflections and scattering contributes to the high MA performance.