Construction of heterointerfaces and honeycomb-like structure for ultrabroad microwave absorption.

Heterointerface design is an effective strategy to improve the effective absorption bandwidth in electromagnetic wave EMW absorbing materials. In this paper, honeycomb-like Fe-doped tremella carbide composites (FCT) with a large number of heterogeneous interfaces were obtained by in-situ construction of multiphase composite particles (Fe3C, Fe3O4, and a-Fe) during the carbonization process. The effects of Fe doping on the phase, structure, morphology, and absorption properties of FCT were investigated. The results show that the porous structure and the heterogeneous interface can significantly improve the electromagnetic wave absorption performance of FCT. Iron doping introduces a heterogeneous multiphase structure into FCT, which increases the interfacial loss and magnetic loss of the material, thereby improving the overall impedance matching of the material. FCT-4 composite exhibited excellent microwave attenuation capability with a reflection loss of -34.6 dB. Simultaneously, the widest effective absorption bandwidth is up to 8.84 GHz (9.16-18 GHz) with a matching thickness of 2.8 mm, which covers almost the entire X (8-12 GHz) and Ku (12-18 GHz) bands. Thus, this paper provides an effective strategy for the preparation of excellent electromagnetic wave absorbing materials by in situ construction of heterointerfaces.