MnCo-MOF-74 derived porous MnO/Co/C heterogeneous nanocomposites for high-efficiency electromagnetic wave absorption

Metal-organic frameworks (MOFs) have attracted more and more attentions for preparing electromagnetic wave (EMW) absorption materials because of the porous structure, high specific surface area, and designable configuration. Herein, a series of MOF-74 derived nanocomposites were synthesized by hydrothermal process and subsequent carbonization. The EMW absorption performance and the functions of each component were investigated in depth. Moreover, the inherent EMW absorption mechanisms were comprehensively revealed. Benefiting from the synergistic effect of constituents and microstructure, the MnCo-MOF-74 derived MnO/Co/C nanocomposites delivered a minimum reflection loss value of −68.89 dB at the thickness of 2.64 mm and an effective absorption band of 5.3 GHz at the thickness of 2.3 mm. The high EMW absorption performance was ascribed to the optimized impedance matching and multiple attenuation mechanisms including interfacial and dipole polarization loss, magnetic loss, conductive loss, and multiple scatterings capability. This study shed light on exploring high-efficiency MOF-based EMW absorption materials with rational design of components and structure.