Interfacial Dynamics in MXene Structures: Functional Pathways Toward Next‐Generation Mixed Matrix Membranes for CO ₂ Separation

Developing effective CO₂ separation technology is essential to ensure environmental remediation. In this endeavor, mixed matrix membranes (MMMs), which synergistically integrate polymer matrices with functional nanofillers (e.g., metal-organic frameworks (MOFs), covalent organic frameworks (COFs), graphene oxide (GO), clay, etc.), have emerged as a frontier in CO₂ separation. Among the diverse spectrum of nanofillers, MXenes, a class of 2D transition metal carbides, nitrides, and carbonitrides, stand out for their tunable layered structure and rich surface functional groups. These features enable molecular sieving pathways, improve polymer-filler interfacial compatibility, reduce agglomeration, and optimize membrane morphology. In this review, the progress of MXene-based MMMs for CO₂ separation is critically examined, with an emphasis on structural characteristics, synthesis techniques, CO₂ transport mechanism, and underpinning interfacial dynamics. The review also covers limitations such as defects, aging, stability, and scalability as drivers of innovation, and highlights prospects for sustainable, high-performance, and industrially applicable CO₂ separation membranes.