Improvement in compressive stiffness of graphene aerogels by sandwiching carbon nanotubes

Recently, much interest has been attracted in the graphene aerogels due to their outstanding properties. However, their weak compressive mechanical performances usually limit their further applications. In this work, we proposed a novel route to enhance the compressive stiffness of graphene aerogels inspired by the structure of leaf, and one kind of CNT sandwiched graphene aerogels (CSGAs) was prepared by a facile freeze-drying method. The compressive testing results show that the sandwiched CNTs can effectively provide mechanical supporting effect, and the compressive mechanical properties of CSGAs are also related to the content of CNTs. In addition, we employed the coarse-grained molecular dynamics (CGMD) simulation to reveal potential mechanical enhancement mechanisms. It is found that when the CNT number in the inter-layer between graphene nanosheets is suitable, the CNTs can form a stable network structure, which can effectively hinder the bending deformation of graphene nanosheets. This work provides a promising structural design route for high-performance graphene-based nanomaterials and broadens their applications.