Preparation of stable carbon nanotube aerogels with high electrical conductivity and porosity

Stable carbon nanotube (CNT) aerogels were produced by forming a three-dimensional assembly of CNTs in solution to create a stable gel using a chemical cross-linker, followed by a CO2 supercritical drying. Thermal annealing of these aerogels in air can significantly improve their electrical and mechanical properties, and increase their surface area and porosity by re-opening the originally blocked micropores and small mesopores in the as-prepared CNT aerogels. Thermally annealed CNT aerogels are mechanically stable and stiff, highly porous (∼99%), and exhibit excellent electrical conductivity (∼1–2 S/cm) and large specific surface area (∼590–680 m2/g).