Enhanced Gas Separation through Nanoconfined Ionic Liquid in Laminated MoS Membrane.

Two-dimensional (2D) materials-based membranes show great potential for gas separation. Herein an ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF]), was confined in the 2D channels of MoS-laminated membranes via an infiltration process. Compared with the corresponding bulk [BMIM][BF], nanoconfined [BMIM][BF] shows an obvious incremental increase in freezing point and a shift of vibration bands. The resulting MoS-supported ionic liquid membrane (MoS SILM) exhibits excellent CO separation performance with high CO permeance (47.88 GPU) and superb selectivity for CO/N (131.42), CO/CH (43.52), and CO/H (14.95), which is much better than that of neat [BMIM][BF] and [BMIM][BF]-based membranes. The outstanding performance of MoS SILMs is attributed to the nanoconfined [BMIM][BF], which enables fast transport of CO. Long-term operation also reveals the durability and stability of the prepared MoS SILMs. The method of confining ILs in the 2D nanochannels of 2D materials may pave a new way for CO capture and separation.