Yang Rujie, Liang Zhuolin, Wu Baolong, Di Yingjie, Lin Yuqing, Wu Shujin, Liu Quan, Liang Shanshan
School of Physics, East China University of Science and Technology, Shanghai, 200237, China.
National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, East China University of Science and Technology, Shanghai, 200237, China.
Small. 2025 Feb;21(7):e2406550. doi: 10.1002/smll.202406550. Epub 2025 Jan 2.
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 h bar) and high NaSO rejection. The density functional theory calculations revealed that IL-rGO nanochannels exhibited different exclusion effects on cations (Na and /or K) and the attraction effect on water molecules, which led to the "cation-recognition" effect. Overall, this work provides a theoretical framework in sub-nanochannels for developing advanced 2D nanochannels to address the critical challenge of freshwater scarcity.
纳米通道中的水和离子传输对于生物系统中基于膜的技术至关重要。二维材料，尤其是最常被用作起始材料的氧化石墨烯（GO），是开发合成膜的理想构建单元。然而，在压力过滤过程中，在选择性排斥小离子的同时保持其性能仍然是氧化石墨烯膜面临的一项挑战。在此，通过离子液体（IL）修饰的还原氧化石墨烯（rGO）膜的纳米通道内引入了一种新型的“阳离子识别”效应，以提高脱盐性能。所得的离子液体插层还原氧化石墨烯（IL-rGO）膜即使在长时间暴露于酸性和碱性条件下也表现出显著的稳定性，不会受损或分层，并保持约超高的水渗透率（≈32.0 L m⁻² h⁻¹ bar⁻¹）和高的Na₂SO₄截留率。密度泛函理论计算表明，IL-rGO纳米通道对阳离子（Na⁺和/或K⁺）表现出不同的排斥效应，对水分子表现出吸引效应，这导致了“阳离子识别”效应。总体而言，这项工作为开发先进的二维纳米通道以应对淡水短缺这一关键挑战提供了亚纳米通道方面的理论框架。
