Hierarchical porous polyacrylonitrile-based activated carbon fibers for CO2 capture

Hierarchical porous activated carbon fibers with a BET surface area of 2231 m2 g−1 and a pore volume of 1.16 cm3 g−1 were made from polyacrylonitrile through pre-oxidation and chemical activation. This type of material contains a large amount of nitrogen-containing groups (N content > 8.1 wt%) and consequently basic sites, resulting in a faster adsorption rate and a higher adsorption capacity for CO2 than pure carbon materials with analogous structures under the same conditions. Moreover, its adsorption capacity for CO2 was more than 3.3-times higher than that for N2. In particular, it showed a much higher CO2 adsorption capacity than zeolite 13X, which is conventionally used to capture CO2, in the presence of H2O.