Facile Size-Selective Defect Sealing in Large-Area Atomically Thin Graphene Membranes for Sub-Nanometer Scale Separations
Facile Size-Selective Defect Sealing in Large-Area Atomically Thin Graphene Membranes for Sub-Nanometer Scale Separations
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DOI：
10.1021/acs.nanolett.0c01934
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发表时间：
2020-08-12
期刊：
影响因子：
10.8
通讯作者：
Kidambi, Piran R.
中科院分区：
文献类型：
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作者：
Cheng, Peifu;Kelly, Mattigan M.;Kidambi, Piran R.
原子级薄的石墨烯具有高密度的精确亚纳米孔，是离子和分子分离的理想膜。然而，单个大纳米孔可能严重损害膜性能，并且石墨烯和原始区域中预先存在的缺陷/晶界之间的差异蚀刻存在根本限制。在这里，我们首次表明，在石墨烯中形成高密度纳米孔后的尺寸选择性界面聚合不仅密封了较大的缺陷（>0.5 nm）和宏观撕裂，而且还成功地保留了较小的亚纳米孔。低温生长，然后是温和的UV/臭氧氧化，允许在石墨烯晶格中容易且可扩展地形成高密度（4-5.5 × 10（12）cm（-2））有用的亚纳米孔。我们展示了可扩展的合成全功能厘米级纳米多孔原子薄膜（NATMs）与水（类似于0.28 nm）的渗透性，比市售膜高出23倍，对盐离子具有优异的截留率在正向渗透下，有机小分子（类似于0.66 nm，>97%截留率）以及小有机分子（类似于0.7-1.5 nm，类似于100%截留率）的渗透率降低。
Atomically thin graphene with a high-density of precise subnanometer pores represents the ideal membrane for ionic and molecular separations. However, a single large-nanopore can severely compromise membrane performance and differential etching between pre-existing defects/grain boundaries in graphene and pristine regions presents fundamental limitations. Here, we show for the first time that size-selective interfacial polymerization after high-density nanopore formation in graphene not only seals larger defects (>0.5 nm) and macroscopic tears but also successfully preserves the smaller subnanometer pores. Low-temperature growth followed by mild UV/ozone oxidation allows for facile and scalable formation of high-density (4-5.5 x 10(12) cm(-2)) useful subnanometer pores in the graphene lattice. We demonstrate scalable synthesis of fully functional centimeter-scale nanoporous atomically thin membranes (NATMs) with water (similar to 0.28 nm) permeance similar to 23X higher than commercially available membranes and excellent rejection to salt ions (similar to 0.66 nm, >97% rejection) as well as small organic molecules (similar to 0.7-1.5 nm, similar to 100% rejection) under forward osmosis.