Robust and Flexible Carbon Nanofibers Doped with Amine Functionalized Carbon Nanotubes for Efficient CO2 Capture

Porous carbon nanofibrous materials have great potential for energy-efficient CO2 capture and separations, but a major hurdle is the lack of mechanical strength and flexibility. Herein, the authors report a facile strategy for the fabrication of amine functionalized carbon nanotube (NC) doped carbon nanofibers (CNFs) (denoted as NC@CNFs) with high flexibility and hierarchical porosity. The NC@CNFs are used as robust fibrous adsorption materials for CO2 capture, which achieve superior CO2 uptake of 6.3 mmol g(-1) at 1.0 bar and 298 K, as well as remarkable CO2/N-2 selectivity and excellent cyclability. Integrating NC into CNFs not only brings number of adsorption sites (i. e., -NH2) and tunable hierarchical pores for CO2 uptake, but also serves as single-fiber-crack connection to prevent NC@CNFs from brittle fracture. More significantly, the flexible NC@CNFs with highly stable structure and mechanical strength can overcome the limitation of easy pulverization and structure collapses for traditional particle-shaped solid sorbents, which makes them highly operable and applicable. This work paves the way for a new route to produce fibrous textile materials with high flexibility and outstanding performance for gas separation.