Ion sieving by a two-dimensional Ti3C2Tx alginate lamellar membrane with stable interlayer spacing
Ion sieving by a two-dimensional Ti3C2Tx alginate lamellar membrane with stable interlayer spacing
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通过具有稳定层间距的二维 Ti3C2TX 藻酸盐层状膜进行离子筛分
DOI：
10.1038/s41467-020-17373-4
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发表时间：
2020-07-15
影响因子：
16.6
通讯作者：
Wang, Lei
中科院分区：
文献类型：
--
作者：
Wang, Jin;Zhang, Zhijie;Wang, Lei
二维膜由于异常输运现象引起了广泛的关注；然而，离子分离性能低于理论预测。稳定d间距是提高离子选择性的关键步骤。在这里，我们展示了一种通过海藻酸盐水凝胶柱稳定Ti3C2Tx层流结构的策略。经海藻酸钙柱支撑后，纳米通道直径有效地固定在7.4±0.2 Å，膜具有渗透切断和对价阳离子的优异筛分性能。当应用于酸回收时，优异的H+/Fe2+选择性使该膜成为传统离子交换膜的有希望的替代品。此外，具有相同d间距的超薄海藻酸锰柱状膜具有100%的Na2SO4截留率和高透水性，优于目前最先进的纳滤膜。在这些发现的基础上，我们展示了一种有效的方法来调节离子选择性，并为能源和环境相关的应用引入了新的视角。
Two-dimensional membranes attract extensive interest due to the anomalous transport phenomena; however, the ion separation performance is below the theoretical prediction. The stabilization of d-spacing is a key step for enhancing ion selectivity. Here, we demonstrate a strategy for stabilizing the Ti3C2Tx laminar architecture by alginate hydrogel pillars. After pillared by Ca-alginate, the nanochannel diameters are effectively fixed at 7.4 ± 0.2 Å, and the membrane presents a permeation cutoff and an outstanding sieving property towards valent cations. When applied for acid recovery, the outstanding H+/Fe2+ selectivity makes the membrane a promising substitution for traditional ion-exchange membranes. Moreover, the ultrathin Mn-alginate pillared membrane with identical d-spacing exhibits 100% Na2SO4 rejection with high water permeance, which is superior to the state-of-the-art nanofiltration membranes. Building on these findings, we demonstrate an efficient method to tune the ion selectivity and introduce a new perspective for energy- and environment-related applications.