Facile synthesis of ZnFe2O4/ZnO/Fe3O4/Fe3N/C composites derived from bimetallic MOFs for efficient electromagnetic wave absorption

Abstract

A novel metal–organic framework (MOF), ZnFe-MOF, was synthesized using a water phase method. By employing an explosion method with ZnFe-MOF as a precursor, a porous carbon composite electromagnetic wave-absorbing powder, ZnFe₂O₄/ZnO/Fe₃O₄/Fe₃N/Fe₂N/Zn/C (ZFC280), was obtained. This study examined the effects of paraffin filling amount and calcination temperature on the absorption performance of carbon composite materials. Notably, when the mass ratio of the absorber to paraffin was 1:1, the nanocomposite absorber ZnFe₂O₄/ZnO/Fe₃O₄/Fe₃N/C (ZFC300) exhibited superior electromagnetic wave absorption capability. The ZFC300 sample demonstrated nearly complete absorption of electromagnetic waves across frequencies from 2 to 18 GHz with thicknesses ranging from 1 to 10 mm. Particularly, ZFC300 achieved a minimum reflection loss of −55.32 dB at 4.31 GHz with the 5.46 mm thickness and exhibited the broadest absorption bandwidth of 4.14 GHz at a thickness of 2.0 mm. The primary loss mechanism of the multicomponent and porous ZFC300 was dielectric loss with supplementary magnetic loss. Owing to its excellent absorption performance, the ZFC300 absorber is be a promising candidate for both civilian and military applications.