Fabrication and efficient electromagnetic waves attenuation of three-dimensional porous reduced graphene oxide/boron nitride/silicon carbide hierarchical structures

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 compos-ites 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 fab-rication of composites can provide a guideline for rational design and fabrication of high-performance electromagnetic waves absorbing materials in practical applications. (c) 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.