Modulating magnetic interface layer on porous carbon heterostructures for efficient microwave absorption

Modern communication systems call for high performance electromagnetic wave absorption materials capable of mitigating microwaves over a wide frequency band. The synergistic effect of structure and component regulation on the electromagnetic wave absorption capacity of materials is considered. In this paper, a new type of three-dimensional porous carbon matrix composite is reported utilizing a reasonable design of surface impedance matching. Specifically, a thin layer of densely arranged Fe-Cr oxide particles is deposited on the surface of porous carbon via thermal reduction to prepare the Fe-Cr-O@PC composites. The effect of Cr doping on the electromagnetic wave absorption performance of the composites and the underlying attenuation mechanism have been uncovered. Consequently, outstanding electromagnetic wave absorption performance has been achieved in the composite, primarily contributed by the enhanced dielectric loss upon Cr doping. Accordingly, an effective absorption bandwidth of 4.08 GHz is achieved at a thickness of 1.4 mm, with a minimum reflection loss value of −52.71 dB. This work not only provides inspiration for the development of novel absorbers with superior performance but also holds significant potential for further advancement and practical application.