Optimizing MOF‐Derived Electromagnetic Wave Absorbers through Gradient Pore Regulation for Pareto Improvement

Abstract

AbstractPorous materials emerging as potential high‐efficiency electromagnetic (EM) wave absorbers confront a critical trade‐off between impedance matching and attenuation capability. In this study, a versatile strategy is reported to overcome this challenge by constructing gradient pores via solvent‐assisted linker exchange for the fabrication of metal‐organic framework (MOF) derived Fe/Fe3Co7/Co/C composites with high porosity. The impedance and attenuation characteristics of single‐pored and gradient‐pored derivatives are investigated through combined experimental and simulation approaches. Simulated space EM field, loss density, and Smith charts reveal significantly enhanced EM interactions and optimized impedance within the pores. Compared to individual MOF derivatives, the gradient derivative exhibits improved impedance matching from the large‐pored shell and superior attenuation capability from the small‐pored core, giving rise to a Pareto improvement in EM absorption with strong reflection loss (−64.7 dB) and wide effective adsorption bandwidth (5.8 GHz) at a thickness of 2.5 mm. This work not only advances a novel gradient pore strategy for constructing efficient absorbers with enhanced impedance matching and attenuation capability, but also sheds light on the underlying mechanisms of EM interaction with varied porosity, offering insights for extended designs in magnetic, electric and optic devices.