One-pot synthesis of Carbon nanotube reinforced graphene aerogels and their applications in electromagnetic wave attenuation

Abstract

Recently, hydrothermal self-assembly fabrication techniques for three-dimensional (3D) graphene aerogels have attracted more and more research attention in developing ideal electromagnetic wave absorbing materials. However, the defect of poor mechanical stability is difficult to overcome due to the disordered weak connection of graphene sheets during self-assembly, which also greatly restrict its practical application value in the field of electromagnetic wave absorbing materials. Here, we prepared a CNTs/graphene aerogel (CGA) with high mechanical stability which composed of one-dimensional (1D) CNTs and two-dimensional (2D) graphene sheets through a facile one-pot hydrothermal strategy. The thoroughly dispersed CNTs inserted on the graphene sheets to form continuous network structures, which not only improved the mechanical properties, but also adjusted the electrical conductivity of graphene sheets, thus enhancing the microwave absorption performance. The CGA-3 exhibits the best mechanical stability as it can withstand a weight of 70 g which is ~800 times of its own weight. Meanwhile, the CGA-3 shows the best electromagnetic wave absorption performance, where the minimum reflection loss could reach −54dB, and the effective absorbing bandwidth is 6.3 GHz (11.7–18 GHz) with an absorbent thickness of 2.3 mm, covering the whole Ku band. This work confirms that the CNTs/graphene aerogels are expected to become ideal absorbers, which is meaningful to extend the structural enhancement and practical application of 3D graphene-based electromagnetic wave absorbing materials.