Guo Bing-Yi, Jiang Shu-Dong, Tang Ming-Jian, Li Kerui, Sun Shipeng, Chen Po-Yen, Zhang Sui
Department of Chemical and Biomolecular Engineering , National University of Singapore , 4 Engineering Drive , Singapore 117585.
State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing 210009 , China.
J Phys Chem Lett. 2019 Aug 15;10(16):4609-4617. doi: 10.1021/acs.jpclett.9b01780. Epub 2019 Aug 1.
This paper reveals the chemical, structural, and separation stability of stacked molybdenum disulfide (MoS) membranes and establishes a low-cost and facile approach to developing stable, selective membranes for efficient molecular separation in an organic solvent. MoS nanoflakes that were dominant by monolayer MoS sheets as prepared via direct chemical exfoliation (chem-MoS) were found to be chemically and structurally instable, with a sharp decrease in the level of solute rejection within a few days. Few-layer MoS nanoflakes were then fabricated using a hydrothermal method (hydro-MoS). A "supportive" drying process involving glycerol pretreatment and drying in an oven was established to allow realignment of nanoflakes and adjustment of interflake spacing. We have shown that the hydro-MoS membranes provide a mean interflake free spacing of ∼1 nm, which is ideal for the separation of a model solute (Rose Bengal, size of ∼1.45 nm) from the solvent isopropanol (size of 0.58 nm) with good long-term stability over a 7 day test.
本文揭示了堆叠式二硫化钼（MoS）膜的化学性质、结构和分离稳定性，并建立了一种低成本且简便的方法来开发稳定、选择性的膜，以在有机溶剂中实现高效分子分离。通过直接化学剥离法（chem-MoS）制备的以单层MoS片为主导的MoS纳米片在化学和结构上不稳定，溶质截留率在几天内急剧下降。随后使用水热法（hydro-MoS）制备了少层MoS纳米片。建立了一种包括甘油预处理和烘箱干燥的“支撑性”干燥工艺，以使纳米片重新排列并调整片间距。我们已经表明，hydro-MoS膜提供了约1 nm的平均片间自由间距，这对于从溶剂异丙醇（尺寸为0.58 nm）中分离模型溶质（孟加拉玫瑰红，尺寸约为1.45 nm）是理想的，并且在7天的测试中具有良好的长期稳定性。
