Interface engineering to develop heterogeneous spindle-shaped FeS2/ NiS2@C nanorods for high-efficient microwave attenuation

With the rapid development of 5G communication technology, the accompanied radiation pollution by electromagnetic waves has become increasingly serious. Therefore, high-performance wave-absorbing materials need to be developed. In this paper, spindle-shaped hierarchical porous composites based on iron metal-organic frameworks (MOFs) coated with hydroxides (Fe3O4/Ni@C, FeS2/NiS2@C, and FeSe2/NiSe2@C) were synthesized. The porous structure with a large specific surface area promotes multiple scattering and reflection of electromagnetic waves, and the unique hierarchical core-shell structure induces interfacial polarization, which is beneficial to improving the absorption of electromagnetic radiation. The doping of heteroatoms can enhance the relaxation process of interfacial polarization and improve the dielectric properties to optimize the impedance matching characteristics of the composites. In particular, the synergistic effect between the magnetic carbon multicomponent, sulfur doping, and hierarchical porous structure of the FeS2/NiS2@C composite significantly improves the microwave absorption performance of the material, and a minimum reflection loss (RLmin) of-59.4 dB at 3.2 mm with a filler loading of 20 wt% was obtained. This work provides a new way for the development of MOF-derived hierarchical magnetic carbon composites doped with strongly polarized elements.