Amine‐functionalized Ti ₃ C ₂ T x MXene‐integrated Nanocomposite Membranes via Vapor‐phase Interfacial Polymerization for CO ₂ Separation

Escalating anthropogenic CO 2 emissions and global decarbonization imperatives are catalyzing a paradigm shift toward membrane‐based gas separation as a scalable and energy‐efficient frontier for post‐combustion CO 2 capture. This work reports a sustainable vapor‐phase interfacial polymerization (VP‐IP) method for fabricating polyamideselective layer in Ti 3 C 2 T x ‐NH 2 MXene‐incorporated thin‐film nanocomposite (TFN) membranes for CO 2 separation. VP‐IP eliminates hazardous volatile organic solvents and provides precise control over polymer chain growth, crosslinking density, and interfacial morphology. MXene serves as a CO 2‐ philic nanofiller, forming hierarchical nanoconfined transport channels that facilitate preferential CO 2 transport. The optimized TFN@0.5MX membrane with 0.5 wt.% Ti 3 C 2 T x ‐NH 2 loading achieves CO 2 permeance of 389.28 GPU and CO 2 /N 2 selectivity of 15.11 at 25 °C and 1 bar pressure. Temperature‐dependent analysis reveals a notable increase in CO 2 permeance to 418.5 GPU with enhance CO 2 /N 2 selectivity to 42.22 at 40 °C, surpassing both the 2019 and 2008 Robeson upper bounds. Systematic structure‐performance correlations under varying thermodynamic conditions reveal a synergistic interplay between molecular sieving sorption selectivity and diffusion path tortuosity, wherein MXene acts as multifunctional sorption‐selective nodes. This sustainable strategy offers a scalable and environmentally benign route for industrial CO 2 capture and circular carbon utilization, aligning with sustainability goals and advancing the transition toward low‐carbon process intensification.