Amino-Functionalized Metal-Organic Framework Fiber Membranes for CO₂ Adsorption

Metal-organic frameworks (MOFs) have attracted attention for CO₂ adsorption owing to their unique pore characteristics and facile functionalization. However, their powdery nature causes poor mechanical stability and low gas mass transfer efficiency, limiting their applications. Herein, we report a promising strategy of in situ assembly of amino-functionalized ZIF-8 (ZIF-8-NH₂) on the surface of nanofibers to create the one-dimensional gas transport pathway while generating hierarchical porous architectures that increase the number of CO₂-philic sites. Benefiting from the created microenvironments, the ZIF-8-NH₂ fiber membranes (FMs) showed a high specific surface area of 248.29 m²/g, a high CO₂ adsorption capacity of 3.25 mmol/g at 298 K and 1 bar, an excellent CO₂/N₂ selectivity of 37, and stable recyclability. Molecular dynamics simulations indicated that amination could enhance the CO₂ affinity of ZIF-8-NH₂ FMs. The gas dynamic breakthrough tests further demonstrated the high separation efficiency of the ZIF-8-NH₂ FMs for the formation of CO₂ and N₂. The proposed collaborative regulation of microenvironments strategy provides a bright orientation for constructing functionalized MOF FMs for efficient CO₂ adsorption.