Bimetallic metal-organic framework aerogels supported by aramid nanofibers for efficient CO₂ capture

The excessive CO₂ emission has gained global attentions due to its potential effects on climate change, plant nutrition deterioration, and human health and safety. Metal-organic frameworks (MOFs) featured with high specific surface area, adjustable pore size, and tailorable morphology have been widely applied for CO₂ capture. However, some drawbacks of poor mechanical stability and uneven distribution of mesopores limit their further applications. Herein, we demonstrate a one-step synthesis of bimetallic center framework (OSSBCF) and pore reconstruction (PRC) strategy to prepare the hierarchical porous Zn/Co-ZIF@ANF aerogels. This unique design achieves the construction of efficient gas transfer channels and creates massive micropores with abundant Lewis basic adsorption sites. Benefiting from theses merits, the bimetallic Zn/Co-ZIF@ANF aerogels demonstrate high MOFs loading mass of 47.51 wt%, high specific surface area of 686.39 m²g^-1, and large porosity of 99.31 %. Moreover, the bimetallic Zn/Co-ZIF@ANF aerogels exhibit an enhanced CO₂ adsorption capacity of 5.99 mmol/g and CO₂/N₂ adsorption selectivity of 35 at 25 °C and 1 bar. The CO₂ capacity of bimetallic Zn/Co-ZIF@ANF aerogels keep up to 95.19 % after ten cycles of CO₂ adsorption, indicating the excellent long-term recycle stability. Therefore, this study provides a promising strategy to engineer hierarchical porous bimetallic MOF aerogels toward practical CO₂ capture.