Fabrication of Ce-based metal–organic framework nanosheets to enhance separation performance and stability of PIM-1 membrane

Two-dimensional (2D) metal–organic framework nanosheets (MONs) materials exhibit significant potential in achieving high CO 2 separation performance. This study presents a demonstration of the rapid synthesis of Ce 6 BTB nanosheets at a low temperature of 80 °C and atmosphere pressure of approximately 1 atm. The resulting Ce 6 BTB nanosheets possess notable characteristics, such as high aspect ratios and 1D diamond shaped channels, which facilitate the fast rapid transport of CO 2 molecules. The Ce 6 BTB was firstly blended into PIM-1 with different loadings to form PIM/Ce 6 BTB mixed matrix membranes (MMMs). The incorporation of well-dispersed Ce 6 BTB fillers enhances the efficiency of CO 2 transport by inter-flake nano-channels and intra-flake pores. Moreover, the increased crystallinity, dense chain spacing, and hydrogen bonding contribute to enhanced sieving ability, resulting in high gas selectivity. Consequently, the MMMs containing 2 wt% Ce 6 BTB demonstrate high CO 2 permeability of 5930 Barrer and CO 2 /N 2 selectivity of 23.2, which is far surpasses 2008 upper bound from Robeson and approaches the refined 2019 upper bound from MeKenow. Furthermore, the PIM/Ce 6 BTB-2 MMMs present relatively good anti-pressure properties and long-term operation stability, which is advantageous in terms of industrial applications.