High-performance thin-film composite (TFC) membranes with 2D nanomaterial interlayers: An overview

Thin-film composite (TFC) membranes have been widely used in various separation and purification fields. However, the inherent "trade off" effect limits further improvement in the separation performance. Recently, the construction of nanomaterial interlayers between porous substrates and the selective layer has been widely investigated to enhance the permeability and selectivity of TFC membranes simultaneously. Among the interlayer materials, two-dimensional (2D) nanomaterials possess high lateral size and large aspect ratios and can be stacked to cover the pores on the substrate surface, providing a smooth and flat surface for interfacial polymerization. In this review, we first briefly introduced the effects of 2D nanomaterial interlayers in TFC membranes, including the roles of 2D nanomaterial interlayers in the interfacial polymerization process and in the membrane performance. Then, interlayers prepared from some typical 2D nanomaterials are detailedly discussed for the preparation of high-performance TFC membranes. The 2D nanomaterials include graphene oxide (GO), graphitic carbon nitride (g-C3N4), MXene, covalent organic framework (COF), metal organic frameworks (MOFs), and some other nanomaterials. In the fourth part, we summarized the typical applications (e.g., nanofiltration and gas separation) of the TFC membranes with 2D nanomaterial interlayers. Furthermore, we suggested the challenges and prospects of high-performance TFC membranes based on 2D nanomaterial interlayers.