Tailoring ion sieving in graphene oxide membranes with high flux by rational intercalating crown ethers

Abstract Two-dimensional (2D) materials-based membranes are extremely promising for ion-selective separation. However, the permeability-selectivity trade-off for 2D membranes limit their development. Herein, we report a precise tailoring of monovalent cation sieving technology with enhanced water throughput, by the use of graphene oxide (GO) membranes with various crown ether intercalations. The enhanced water-flux of the membranes is due to the expansion of GO interlayers by intercalating crown ethers. We also reveal a systematic study on the limit interlayer size for ion-selective transport in the GO laminas. As a result, remarkably high ion selectivity for different specific cations could be achieved, which is mainly ascribed to the chelation between selective ions and crown ether in the GO laminates. This work opens up a new avenue on precisely regulating ion separations for various application scenarios.