Department of Chemical and Biomolecular Engineering, National University of Singapore , Singapore 117585, Singapore.
ACS Appl Mater Interfaces. 2017 Aug 23;9(33):28079-28088. doi: 10.1021/acsami.7b08383. Epub 2017 Aug 8.
Herein, a two-dimensional metal-organic framework (2D MOF) made of iron porphyrin complex (TCP(Fe)) interconnected with divalent metal ion (M = Zn, Co, and Cu) is used to construct a selective layer, which is explored as an ultrafast and energy-saving nanofiltration (NF) membrane for removing organic dyes from water. Among the layered 2D M-TCP(Fe) membranes, Zn-TCP(Fe) membranes display the highest water permeance, which is 3 times higher than graphene-based membranes with similar rejection. To further improve the separation performances, we utilize polycations to anchor the periphery carboxylic groups of nanosheets, regulating the assembly of 2D Zn-TCP(Fe) nanosheets to produce a new class of crack-free selective layer possessing ultrathin and highly ordered nanochannels for efficient NF. Benefiting from these structural features, our polycation-regulated 2D Zn-TCP(Fe) membranes could offer ultrahigh permeance of 4243 L m h bar (2-fold higher than its pristine) and excellent rejection rates (over 90%) for organic dye with size larger than 0.8 × 1.1 nm. This permeance value is about 2 orders of magnitude higher than the commercial polymeric NF membrane. Additionally, the membranes demonstrate 20-40% salt rejection.
本文采用由二价金属离子（M=Zn、Co 和 Cu）连接的铁卟啉配合物（TCP(Fe)）二维金属有机骨架（2D MOF）构建选择性层，探索其作为一种超快、节能的纳滤（NF）膜，用于从水中去除有机染料。在层状 2D M-TCP(Fe) 膜中，Zn-TCP(Fe) 膜具有最高的水透过率，是具有类似截留率的基于石墨烯膜的 3 倍。为了进一步提高分离性能，我们利用聚阳离子来锚定纳米片的外围羧酸基团，调节 2D Zn-TCP(Fe) 纳米片的组装，生成具有超薄和高度有序纳米通道的新型无裂缝选择性层，用于高效纳滤。得益于这些结构特征，我们的聚阳离子调节的 2D Zn-TCP(Fe) 膜可以提供超高的渗透通量（比其原始膜高 2 倍，达到 4243 L m h bar）和对尺寸大于 0.8 × 1.1nm 的有机染料的优异截留率（超过 90%）。该渗透通量值比商业聚合物纳滤膜高 2 个数量级。此外，该膜还表现出 20-40%的盐截留率。
