Fe-MOFs derived porous Fe4N@carbon composites with excellent broadband electromagnetic wave absorption properties

Abstract

Designing components and optimizing structure is considered an effective strategy to enhance the electromagnetic wave absorption of materials. In this study, a two-step method was successfully used to fabricate Fe-metal-organic framework derived iron nitride and carbon-based composites, which combined the porous structure of metal-organic frameworks with the excellent electromagnetic properties of Fe 4 N. By comparing the composite samples' morphology, structure, composition characteristics, and electromagnetic properties before and after nitriding, reasons for improving electromagnetic wave absorption performance are revealed. The formation of the Fe 4 N phase and the porous structure optimize impedance matching, which significantly enhances the electromagnetic wave absorption capacity of the composite. When the Fe 4 N @ carbon composite has a matching thickness of 2 mm, the minimum reflection loss reaches − 56 dB, and when the matching thickness is 2.5 mm, the reflection loss reaches − 42 dB at 13.4 GHz. The effective absorption bandwidth reaches 6.7 GHz. This research brings a new design scheme for improving electromagnetic wave absorption materials. • Fe 4 N @ C composite derived from Fe-metal organic framework was synthesized. • The porous structure and the synergy of dielectric and magnetic loss contribute to electromagnetic wave absorption. • The RL min is − 56 dB with a thickness of 2 mm, and effective absorption bandwidth of 6.7 GHz can be reached with 2.5 mm. • Multiple attenuation mechanisms of the Fe 4 N @ C composite are clarified.