Covalent organic frameworks (COFs) have been widely used to prepare separation membranes due to their high porosity. In this work, a kind of thin-film nanocomposite (TFN) reverse osmosis (RO) membrane was fabricated by forming a polyamide (PA) selective layer on an in-situ constructed two-dimensional COFs intermediate layer. The TFN RO membrane has a much smooth (∼48 nm) and defect-free PA layer due to the regulated interfacial polymerization (IP) process with the assistance of the conterminous COFs interlayer, thereby achieving synchronously improved water permeance of 29.8 L m⁻² h⁻¹ MPa⁻¹ and salt rejection of 99.4 %, as well as excellent chemical stability, including acid / alkali, fouling and chlorine resistance. Moreover, the COFs-interlayered TFN RO membrane exhibited promising separation performance after 80 h long-term filtration test. The current work offers fundamental insights into the critical roles of COFs interlayer in tailoring the IP process and the physicochemical properties of the PA layer, providing a novel strategy for enhancing the separation performance of RO membranes towards efficient desalination and sustainable water purification.

共价有机骨架（COFs）由于其高孔隙率已被广泛用于制备分离膜。在这项工作中，通过在原位构建的二维 COF 中间层上形成聚酰胺 (PA) 选择性层，制备了一种薄膜纳米复合材料 (TFN) 反渗透 (RO) 膜。由于受调节的界面聚合（IP）工艺和连续的 COFs 夹层的帮助，TFN RO 膜具有非常光滑（~48 nm）和无缺陷的 PA 层，从而实现了 29.8 L m ^-2的同步改善的透水性h ^-1兆帕^-1和 99.4% 的脱盐率，以及出色的化学稳定性，包括酸/碱、污垢和氯抗性。此外，经过 80 小时的长期过滤试验，COFs 夹层 TFN RO 膜表现出良好的分离性能。目前的工作为 COF 中间层在定制 IP 工艺和 PA 层的物理化学性质中的关键作用提供了基本见解，为提高 RO 膜的分离性能以实现高效脱盐和可持续水净化提供了一种新策略。