Preparation of lightweight layered porous SiC nanowires/RGO composites with excellent electromagnetic wave absorption performance

Abstract

Designing composite electromagnetic wave absorption (EWA) materials with a strategic structure is a key approach to improve the EWA efficiency of SiC nanowires (SiC_NWs). In this study, SiC_NWs/reduced graphene oxide (SiC_NWs/RGO) composites with layered porous structures were successfully prepared using homemade SiC_NWs and graphene oxide (GO) using simple freeze-drying and heat treatment techniques. Then the EWA performance of SiC_NWs/RGO with different filling amounts (5 wt%, 15 wt% and 25 wt%) was investigated. A minimum reflection loss (RL_min) value of −47 dB at 12.7 GHz was achieved when SiC_NWs/RGO was filled with 5 wt% and the coating thickness was 2.2 mm. When the coating thickness was reduced to 2.0 mm, the effective absorption bandwidth (EAB) extended to 5.78 GHz (12.02 to 17.8 GHz), covering the entire Ku band. The outstanding EWA performance was primarily due to the layered porous structure, which facilitates multiple reflections and scattering of electromagnetic waves (EMWs). This structure not only lengthened the wave attenuation path but also worked synergistically with dielectric and conductive losses. The SiC_NWs/RGO composites prepared in this study are characterized by light weight, thin thickness and high absorption rate, enabling them to be particularly suitable for electromagnetic shielding in the field of livelihood and ecology.