SiCnw@SiC foam prepared based on vapor-solid mechanism for efficient microwave absorption

摘要

? 2022A SiCnw@SiC foam with highly efficient microwave absorption (MA) performance was successfully synthesized based on Vapor-Solid (V–S) growth mechanism. SiC nanowire (SiCnw) and SiC foam skeleton efficiently form a double network coupling structure, which gives additional interface polarization and dielectric loss for the SiC foam, significantly enhancing the MA capacity of the foam. In this study, the SiCnw@SiC foam has a minimum reflection loss (RLmin) of ?86.31 dB and an effective absorption bandwidth (EAB) of 12.55 GHz in room-temperature environment. However, the MA performance of SiCnw@SiC foam decreases with increasing temperature, which may be due to the thickening of the SiO2 layer in the SiCnw at high temperature. At 600 °C, it has no effective absorption bandwidth, while at 1000 °C, the EAB and RLmin were 0.6 GHz and ?13.04 dB, respectively. As the temperature reaches 1000 °C, the defects in the material further increase, leading to a recovery in the MA performance.