Synthesis of Fe/Co bimetallic metal–organic framework‐derived composites and their enhanced electromagnetic wave absorption

Metal-organic frameworks (MOFs) have been garnering considerable attention for application in high‐performance electromagnetic wave absorber owing to their unique ability to reduce the reflection of waves, thereby preventing the deterioration of electronics and human health. To further enhance their absorption performance, this study synthesized uniform‐particle‐sized Fe/Co bimetallic MOF derivatives of CoFe₂O₄ and FeCo/C via calcination and pyrolysis, respectively, of the MIL‐88A‐structured FeCo‐MOF. In general, MOF derivatives of CoFe₂O₄ and FeCo/C primarily function as central regulators of dielectric properties and a source of high polarization loss and conductive loss, respectively, in addition to a high magnetic loss. The integration of homogenous MOF derivatives contributes to the synergistic effects that aid in achieving a suitable impedance matching with a strong attenuation capacity to form an improved absorber. Upon regulating the proportion of the derivatives, a minimum reflection loss of − 52.29 dB at 10.78 GHz at a thickness of 1.9 mm and an effective bandwidth of 7.23 GHz (19.24–26.47 GHz) below − 10 dB at a thickness of 0.9 mm were achieved. Therefore, this study presents a new strategy to design excellent electromagnetic wave absorbers with strong absorption and broad effective bandwidth at a low matching thickness for comprehensive applications.

The electromagnetic wave absorption performance is optimized through the synergistic effects of the hybridization of MOF derivatives.