Bimetallic Metal-Organic Framework-Derived ZnO/Co@Porous Carbon with Tunable Components and Heterostructure for Ultrawide Dual-Band Electromagnetic Wave Absorption

The design of high-performance electromagnetic wave (EMW) absorbers utilizing metal-organic framework (MOF) derivatives has garnered significant attention. However, enabling it to implement dual-band EMW absorption (EMWA) with a sole material remains a substantial challenge. Herein, we devise a strategy involving bimetallic Zn/Co-MOF precursors and realize the modulation of their micro-nanostructure via altering the molar ratio of Zn/Co. ZnO/Co@porous carbon (PC) composites are successfully fabricated via pyrolysis with advanced dual-band EMWA properties, attributed to the synergistic effect of the multiphase heterogeneous structure, impedance matching, and multiple magnetic dielectric loss mechanisms. Zn0.1Co0.9-BTC-derived ZnO/Co@PC composites exhibit good performance with the minimum reflection loss/the maximum effective absorption bandwidth values of -69.3 dB/6.3 and -48.8 dB/7.2 GHz, in the range of 2-18 and 26.5-40 GHz with minimum thicknesses. The superior dual-band attenuation properties of the as-prepared material have been verified by radar cross-section simulation. This research paves the way for novel guidance for utilizing MOF derivatives as potential candidates for dual-band compatible EWMA and offers profound insight into the underlying mechanism of microwave absorption with dual bands.