A Versatile Route toward the Electromagnetic Functionalization of Metal-Organic Framework-Derived Three-Dimensional...

Designable electromagnetic parameters accompanied by a low density of metal-organic framework (MOF)-derived metal/carbon composites are essential prerequisites for excellent microwave-absorbing materials. However, the conventional route is confined to slight modification of the physicochemical properties of metal species and carbon, which also restricts the functionalization of MOF-derived materials. Here, a facile technique has been improved by making full use of highly porous structure to uniformly introduce metallic Co nanoparticles into carbon matrix derived from Cu₃(btc)₂. Through changing the starting amount of Co sources, the composition of the final products can be tuned, offering an effective route to control electromagnetic properties. Multiple attenuation mechanisms are employed to realize excellent reflection loss performance, which can be clarified by modified equivalent circuit mode. Effective frequency bandwidth ( f_e) over the whole X band can be obtained by optimizing interfacial polarization through changing interface area and electrical conductivity. Broad f_e covering almost the whole K_u band from 12.3 to 18 GHz with a thin thickness of 1.85 mm can be gained through improving impedance matching and enhancing conduction loss. The present work not only sheds light on the easy fabrication of high-performance lightweight microwave-absorbing materials but also paves the way for extending functionalities of MOF-derived carbon composites.