Carbon Nanoflakes and Nanotubes from Halloysite Nanoclays and their Superior Performance in CO2 Capture and Energy Storage

Nanoporous carbon (HNC) with flake and nanotubular morphology and a high specific surface area is prepared by using natural halloysite nanotube (HNT), a low cost and naturally available clay material with a mixture of flaky and tubular morphology. A controlled pore filling technique is used to selectively control the porosity, morphology and the specific surface area of the HNC. Activated nanoporous carbon (AHNC) with a high specific surface area is also prepared by using HNT together with the activation process with zinc chloride (ZnCl2). HNC exhibits flakes and tubular morphologies which offer a high specific surface area (837 m2/g). The specific surface area of AHNC is 1646 m2/g, 74 times greater than the specific surface area of pure HNT (22.5 m2/g). These data revealed that the single step activation combined with the nanotemplating results in creating a huge impact on the specific surface area of the HNC. Both HNC and AHNC are employed as adsorbents for CO2 adsorption at different pressures and adso...