In this work, hierarchical hybrid composites consisting of porous three-dimensional reduced graphene oxide (3D-rGO) skeleton and lamellar boron nitride (BN)/silicon carbide (SiC) coatings are prepared by chemical vapor infiltration (CVI) process. The graphene framework prepared by 3D printing and frozen self-assembly exhibits a lightweight structure and a perforated conductive network, which extends the transmission path of incident microwaves. The introduced ceramic coatings can effectively tune the impedance matching degree and supply a lossy phase, and the hierarchical structure of the composites enhances the multiple scattering of the incident microwaves. As expected, the 3D-rGO/BN/SiC composites possess an excellent absorbing performance with a minimum reflection loss value of –37.8 dB, and the widest effective absorbing bandwidth (RL < –10 dB) of 5.90 GHz is obtained. The controllable fabrication of composites can provide a guideline for rational design and fabrication of high-performance electromagnetic waves absorbing materials in practical applications.

在这项工作中，通过化学气相渗透 (CVI) 工艺制备了由多孔三维还原氧化石墨烯 (3D-rGO) 骨架和层状氮化硼 (BN)/碳化硅 (SiC) 涂层组成的分层杂化复合材料。通过 3D 打印和冷冻自组装制备的石墨烯框架具有轻质结构和穿孔导电网络，可延长入射微波的传输路径。引入的陶瓷涂层可以有效地调节阻抗匹配度并提供有损相，复合材料的分层结构增强了入射微波的多次散射。正如预期的那样，3D-rGO/BN/SiC 复合材料具有出色的吸收性能，最小反射损耗值为 –37.8 dB，有效吸收带宽最宽（RL < –10 dB) 的 5.90 GHz。复合材料的可控制备可为实际应用中高性能电磁波吸收材料的合理设计和制备提供指导。