双金属MOF衍生的CoZn-C/MWCNTs复合材料用于轻质宽带微波吸收OA

Achieving high-performance microwave absorbers characterized by wide bandwidth,robust absorption,lightweight properties,and thin profiles remains a critical challenge within modern radar stealth and electromagnetic compatibility domains.In this study,we introduce a straightforward and cost-effective strategy for fabricating lightweight and efficient microwave absorbers utilizing composites derived from bimetallic zeolitic imidazolate frameworks(ZIFs).A variety of ZIF-8@ZIF-67 precursors incorporating multi-walled carbon nanotubes(MWCNTs)were synthesized through a sequential wet-chemical process.These precursors underwent conversion into porous bimetallic MOF-derived CoZn-C/MWCNTs composites via subsequent pyrolysis.The composition,microstructure,and electromagnetic characteristics of the pyrolyzed materials were precisely regulated by varying the Co/Zn molar ratio within the precursors.Due to the synergistic magnetic and dielectric dissipations,the 3:1 Co/Zn composite exhibited the best attenuation constant and impedance matching among all synthesized samples.Thus,the optimized composite provided a significant effective absorption bandwidth of 5.29 GHz at a thickness of 1.9 mm,coupled with an outstanding minimum reflection loss of-23.78 dB at 2.0 mm,even with a minimal filler loading of 20 wt.％.The enhanced scattering suppression behavior was additionally verified through radar cross-section simulation.This research provides a novel viewpoint on the rational design of lightweight MOF-based composites for broadband electromagnetic wave absorption performance.