Fabrication of Co/C@CNFs/GO Aerogels with Directional Channel Structures for Broadband Electromagnetic Wave Absorption

To obtain high-performance electromagnetic wave (EMW) absorption materials with a broad effective absorption bandwidth (EAB), structural design has proven to be an effective strategy. In this investigation, Co/C@carbon nanofibers (Co/C@CNFs) derived from metal-organic frameworks (MOFs) were integrated with graphite oxide (GO) nanosheets, and Co/C@CNFs/GO aerogels were prepared through unidirectional freeze-drying followed by heat treatment. The resulting aerogels exhibit a unique directional channel structure that increases their contact area with air, thereby improving impedance matching. The Co/C@CNFs/GO aerogels demonstrate exceptional EMW capabilities, primarily due to the multiple heterogeneous interfaces and the synergistic electromagnetic loss mechanisms generated by the interactions among GO nanosheets, CNFs, and Co particles. The results reveal that Co/C@CNFs/GO-2 achieves remarkable EMW absorption with a maximum EAB of 10.0   GHz, covering both the X and Ku bands, thanks to its directional channel structure and complete conductive network. Moreover, the aerogels exhibit excellent radar cross-section attenuation and superior thermal insulation. This work provides a reliable strategy for synthesizing multifunctional carbon-based aerogels materials with efficient EMW absorption, offering broad potential for applications in electromagnetic protection, thermal management, and related fields.