Accelerating NH ₃ Transport Through Nanoconfined Functionalized Ionic Liquid in Graphene Oxide Membrane

ABSTRACT Graphene oxide (GO) holds great promise for fabricating high‐flux separation membranes, yet its inherent interlayer defects often compromise precise molecular sieving, particularly for challenging separations such as selective ammonia (NH 3 ) capture and purification. In this work, a functionalized ionic liquid ([DBEAH][NTf 2 ]) with protic hydrogen and hydroxyl groups as NH 3 ‐interactive sites is designed and confined within GO interlayers via hydrogen bonding and electrostatic interactions, thereby constructing tailored pathways for selective NH 3 transport. The incorporated [DBEAH][NTf 2 ] not only modulates the interlayer spacing of GO but also modifies the nanochannels to create an NH 3 ‐affinitive environment for precise recognition and separation of NH 3 . The resulting IL‐confined GO membrane achieves an outstanding combination of high NH 3 permeance of 682.17 GPU and ultrahigh ideal NH 3 /N 2 selectivity of 1488.41 in single‐gas tests. Under mixed‑gas conditions (50/50 vol%, NH 3 /N 2 ), the membrane maintains a high NH 3 permeance of 493.82 GPU and an NH 3 /N 2 separation factor of 248.34. Theoretical simulations further confirm that the confined [DBEAH][NTf 2 ] facilitates rapid and selective transport of NH 3 while effectively blocking N 2 , providing a mechanistic understanding of the enhanced separation performance. This study offers a feasible strategy for designing 2D membranes with simultaneously high permeance, selectivity, and stability for NH 3 separation applications.