Fast permeation and effective solute-solute separation provide the opportunities for sustainable water treatment, but they are hindered by ineffective membranes. We present here the construction of a nanofiltration membrane with fast permeation, high rejection, and precise Cl^-/SO₄^2- separation by spatial and temporal control of interfacial polymerization via graphitic carbon nitride (g-C₃N₄). The g-C₃N₄ nanosheet binds preferentially with piperazine and tiles the water-hexane interface as revealed by molecular dynamics studies, thus lowering the diffusion rate of PIP by one order of magnitude and restricting its diffusion pathways towards the hexane phase. As a result, membranes with nanoscale ordered hollow structure are created. Transport mechanism across the structure is clarified using computational fluid dynamics simulation. Increased surface area, lower thickness, and a hollow ordered structure are identified as the key contributors to the water permeance of 105 L m²·h⁻¹·bar⁻¹ with a Na₂SO₄ rejection of 99.4% and a Cl^-/SO₄^2- selectivity of 130, which is superior to state-of-the-art NF membranes. Our approach for tuning the membrane microstructure enables the development of ultra-permeability and excellent selectivity for ion-ion separation, water purification, desalination, and organics removal.

快速渗透和有效的溶质-溶质分离为可持续水处理提供了机会，但它们受到无效膜的阻碍。我们在这里展示了通过石墨氮化碳 (gC ₃ N ₄ )界面聚合的空间和时间控制，构建具有快速渗透、高截留和精确 Cl ^- /SO ₄ ^{2-分离的纳滤膜。}gC ₃ N ₄分子动力学研究表明，纳米片优先与哌嗪结合并平铺水-己烷界面，从而将 PIP 的扩散速率降低一个数量级，并限制其向己烷相的扩散途径。结果，产生了具有纳米级有序中空结构的膜。使用计算流体动力学模拟阐明了跨结构的传输机制。^{表面积增加、厚度降低和中空有序结构被确定为 105 L m 2} ·h ⁻¹ ·bar ⁻¹透水率的主要贡献者，Na ₂ SO ₄截留率为 99.4%，Cl ^- /所以₄ ^2-选择性为 130，优于最先进的 NF 膜。我们调整膜微观结构的方法能够为离子-离子分离、水净化、脱盐和有机物去除开发超渗透性和出色的选择性。