Low Weight, low thermal Conductivity, and highly efficient electromagnetic wave absorption of Three-Dimensional Graphene/SiC-nanosheets aerogel

With the rapid development of modern information technology, high-level electromagnetic wave (EMW) absorbing materials are playing an increasingly important role in military and civilian fields. However, current EMW absorbers usually have narrow absorption bandwidths and low absorption strengths , which hinder their practical applications. Herein, lightweight aerogels with low thermal conductivity and highly efficient EMW absorption were fabricated via a sol–gel method and subsequent carbothermal reduction with a simple chemical reaction process. The as-prepared graphene/SiC-nanosheets aerogels are composed of a large number of the interconnected two-dimensional SiC nanosheets and graphene sheets with abundant micrometer-sized pores that favored impedance matching, which endows the aerogels with outstanding EMW-absorbing performance. Conductive loss and interfacial polarization further promote the EMW-absorbing of the graphene/SiC-nanosheets aerogels. In addition, the highly porous and interconnected three-dimensional graphene/SiC-nanosheets aerogel networks not only facilitate the absorption of infiltrated EM waves via multiple reflection but also effectively reduce the number of heat transmission routes in the aerogels. The as-prepared SiC/G-2 aerogel exhibites excellent EMW-absorbing property, with a RL min of −65.08 dB at a frequency of 13.20 GHz, a thickness of 3.5 mm and an EAB of 2.21 GHz. These results demonstrate that the as-prepared graphene/SiC-nanosheets aerogel is fascinating material with possible applications in high-performance EMW-absorbing and heat-insulating in the aviation and aerospace fields.