“Cation‐Recognition” Effect of 2D Nanochannels in Graphene Oxide Membranes Intercalated with Ionic Liquid for High Desalination Performance

Water and ion transport in nanochannels is crucial for membrane-based technology in biological systems. 2D materials, especially graphene oxide (GO), the most frequently used as the starting material, are ideal building blocks for developing synthetic membranes. However, the selective exclusion of small ions while maintaining in a pressured filtration process remains a challenge for GO membranes. Herein, a novel "cation-recognition" effect is introduced within the nanochannels of reduced GO (rGO) membranes modified by ionic liquids (IL) to enhance the desalination performance. The resulting IL-intercalated rGO (IL-rGO) membranes exhibit remarkable stability even under prolonged exposure to acidic and basic conditions, without damage or delamination and maintain approximately ultrahigh water permeance (≈32.0 L m