ABSTRACT
Aerogels can be made of a wide variety of substances, including silica, most of the transition metal oxides, lanthanide and actinide metal oxides, several main group metal oxides, organic polymers, semiconductor nanostructures, metals, and carbon-based nanomaterials. Carbon nanotube (CNT) aerogels can also be synthesized by embedding CNTs into other three-dimensional (3D) aerogel structures. Graphene–CNT hybrid aerogels combined with a 3D network of graphene and CNTs have been successfully developed for various applications such as for Lithium Ion Batteries, transparent conductors, and capacitive deionization electrodes for water purification. Noble particles were in situ present and facilitated the nucleation and assembly of the graphene nanosheets during the hydrothermal process. The effects of various drying methods and reducing agents on the electrical properties of graphene aerogels (GAs) were investigated. Compared to GAs, CNT aerogels could achieve slightly higher electrical conductivities because of their relatively more integral graphitic lattice.
