Preparation of Two-Dimensional Nanoconfined Ionic Liquid Membrane and Its Molecular Mechanism of CO2 Separation

The realization of efficient and stable carbon dioxide (CO2) separation technology holds profound significance for the development of green chemistry. In comparison with other CO2 separation technologies, membrane separation technology has the advantages of low energy consumption and simple operation. When used in conjunction with gas separation membranes, ionic liquids are always placed into the nanochannel constructed by two-dimensional nanosheets, forming the nanoconfined ionic liquid membrane (NC-ILM), which has exhibited excellent CO2 separation performance with high permeation and selectivity. In this review, we have summarized the structure and properties of nanoconfined ILs, the separation mechanism, and investigated methods of NCILMs, further discussing the challenges and strategies for the future application of NC-ILMs. Those results on the NC-ILMs not only can deepen the understanding of the molecular mechanism of separating CO2 but also promote the preparation technology of the related membrane with precise nanochannels.