Hierarchical carbon fiber reinforced SiC/C aerogels with efficient electromagnetic wave absorption properties

Rational microstructure design is confirmed to be a practical strategy for achieving high-performance electromagnetic (EM) wave absorbers. Herein, hierarchical carbon fiber reinforced SiC/C (CF-SC) aerogel is prepared via a simple method, in which carbon fibers are incorporated into the hydrogel using a free radical polymerization reaction to form a three-dimensional (3D) framework, and SiC is introduced through a carbothermal reduction reaction. Remarkably, the lightweight CF-SC aerogel achieves exceptional absorption performance compared to all reported carbon- and ceramic-based materials, with a reflection loss (RL) of −52.6 dB and an effective absorption bandwidth (EAB) of 8.6 GHz covering the entire Ku-band at the thickness of 3.2 mm. The experimental and theoretical calculations demonstrate that the outstanding absorption performance benefits from the perfect impedance matching and strong attenuation capability formed by interconnected 3D conductive networks and extensive heterogeneous interfaces. This study is of great significance in guiding the design and mechanism investigation of high-performance EM wave absorbers.