Fibrous Metal–Organic Framework Membranes with Hierarchical Porous Channels for Efficient Carbon Dioxide Capture

The structural diversity and facile functionalization of metal–organic frameworks (MOFs) render them promising candidates for carbon dioxide (CO 2 ) adsorption and separation. However, the powdery characteristics cause poor mechanical stability and insufficient gas mass transfer, restricting their further applications. Herein, we report a promising strategy of in situ assembling ZIF-8 on the inner and outer surfaces of nanofibers to develop the fibrous ZIF-8 membranes with hierarchical porous channels. Particularly, the developed meso/macropores of the fibrous ZIF-8 membranes could facilitate the transport of CO 2 into ZIF-8, and the micropores of ZIF-8 offered massive active CO 2 adsorption sites. As a benefit from the unique design, the resulting fibrous ZIF-8 membranes had some fascinating features, including a high specific surface area of 273.29 m 2 /g and a high mechanical stress of 13.56 MPa. Moreover, the fibrous ZIF-8 membranes demonstrated a high CO 2 adsorption capacity of 3.14 mmol/g at 298 K and 1 bar and an excellent CO 2 /N 2 selectivity of 35. After multiple cycles, the PAN/PVP/ZIF-8 membranes maintained 96.28% of their original CO 2 adsorption capacity. Furthermore, molecular dynamics simulations verify the robust binding interactions of the fibrous ZIF-8 membranes with CO 2 molecules. The integrated hierarchical porous channels proposed in this study provide a promising direction for designing fibrous MOF membranes for highly efficient CO 2 adsorption from flue gas.