Nanopore construction in SiC aerogels for continuous dual-peak electromagnetic wave absorption with full Ku-band coverage

Abstract

SiC aerogels have been extensively studied for electromagnetic wave (EMW) absorption because of their tunable dielectric properties. Continuous dual-peak EMW absorption can broaden the effective absorption bandwidth (EAB); however, few SiC aerogels have been reported to exhibit this phenomenon and the mechanisms to achieve this through microstructure design remain unclear. In this study, size-tunable nanopores were constructed in SiC aerogel by a simple carbothermal reduction method, which gradually increase with increasing reaction temperature. The mechanism of the nanopore formation in SiC aerogels is also discussed in detail. The optimized SiC aerogel prepared at a reaction temperature of 1550 °C exhibited continuous dual-peak EMW absorption with a maximum EAB of 6.24 GHz (11.76–18 GHz), full Ku-band coverage, and minimum reflection loss of −32.59 dB. This continuous dual-peak EMW absorption was ascribed to the overlap of the secondary peak caused by the nanopore-induced strong dielectric resonance and the main peak caused by SiC. The results of this study will provide inspiration for the design of microstructures for continuous dual-peak absorption in EMW absorption materials.