Flexible nanofibrous membranes of dual metallic metal-organic framework with enhanced Lewis basic sites and high...

Excessive CO₂ emissions and the resultant global warming present significant environmental challenges, posing threats to human health and public safety. Metal-organic frameworks (MOFs), known for their high specific area and large porosity, hold the promise for CO₂ capture. However, a major obstacle is the low loading mass of MOFs and the limited interface affinity and compatibility between MOFs and substrates. In this study, we present an electrospinning-assisted in-situ synthesis dual metallic framework strategy for preparing flexible Zn/Co-ZIF nanofibrous membranes (NFMs). This method achieves the high loading mass of MOFs and introduces abundant Lewis basic sites, thereby enhancing the CO₂ adsorption. The dual metallic Zn/Co-ZIF NFMs exhibit remarkable features, including high MOF loading mass (70.23 wt%), high specific surface area (379.63 m²g^-1), large porosity (92.34 %), high CO₂ adsorption capacity (4.43 mmol/g), high CO₂/N₂ adsorption selectivity (37), and high CO₂/CH₄ adsorption selectivity (31). Moreover, the dual metallic Zn/Co-ZIF NFMs demonstrate robust structural stability and durability attributed to the excellent interface affinity between MOFs and NFMs, retaining 96.56 % of their initial capacity after 10 adsorption-desorption cycles. This work presents a prospective direction for developing flexible dual metallic MOF NFMs for the efficient capture of CO₂.