High-Performance CO₂ Capture through Polymer-Based Ultrathin Membranes

Thin film composite (TFC) membranes have attracted great research interest for a wide range of separation processes owing to their potential to achieve excellent permeance. However, it still remains challenging to fully exploit the superiority of thin selective layers when mitigating the pore intrusion phenomenon. Herein, a facile and generic interface-decoration-layer strategy collaborating with molecular-scale organic–inorganic hybridization in the selective layer to obtain a high-performance ultrathin film composite (UTFC) membrane for CO₂ capture is reported. The interface-decoration layer of copper hydroxide nanofibers (CHNs) enables the formation of an ultrathin selective layer (≈100 nm), achieving a 2.5-fold increase in gas permeance. The organic part in the molecular-scale hybrid material contributes to facilitating CO₂-selective adsorption while the inorganic part assists in maintaining robust membrane structure, thus remarkably improving the selectivity toward CO₂. As a result, the as-prepared membrane shows a high CO₂ permeance of 2860 GPU, superior to state-of-the-art polymer membranes, with a CO₂/N₂ selectivity of 28.2. The synergistic strategy proposed here can be extended to a wide range of polymers, holding great potential to produce high-efficiency ultrathin membranes for molecular separation.