Abstract Graphene oxide (GO)-based nanofiltration membranes, featuring well-ordered microscopic structure, well-defined 2D nanochannels and superior molecular sieving ability, have attracted sustained research interest in molecular and ionic separation. However, most of current GO laminar membrane have a poor water flux and high rejection of both dyes and salts, which is not suitable for the dye/salt mixture separation. Herein, we report a vacuum filtration strategy to fabricate GO/NH2-Fe3O4 nanofiltration membranes with high water flux and excellent separation performance for dye/salts mixture by introducing NH2-Fe3O4. The NH2-Fe3O4 is not only worked as the rigid spherical nanospacer to tune GO interlayer spacing but also as crosslinkers to improve the stability of GO membrane in water. FTIR, XRD, SEM, zeta potential and contact angle were applied to analyze the chemical composition and morphology of as-prepared membranes. The effect of intercalated NH2-Fe3O4 nanoparticles on overall performance of the GO/NH2-Fe3O4 membranes was systematically investigated. The resulted membrane with 8 wt% of NH2-Fe3O4 loading has high water flux of up to 78 Lm−2 h−1, which is 4.8 times higher than that of pure GO membrane. Moreover, such membrane also displays high congo red rejection (94%) and low NaCl rejection (~15%), rendering the membranes promising for dye/salt mixtures separation.

中文翻译：

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NH2-Fe3O4 调节的氧化石墨烯膜具有明确的层状纳米通道，用于染料溶液的脱盐

摘要 基于氧化石墨烯（GO）的纳滤膜具有有序的微观结构、明确的二维纳米通道和优异的分子筛分能力，在分子和离子分离方面引起了持续的研究兴趣。然而，目前大多数GO层状膜的水通量较差，对染料和盐的截留率都很高，不适用于染料/盐混合物的分离。在此，我们报告了一种真空过滤策略，通过引入 NH2-Fe3O4 来制造具有高水通量和优异的染料/盐混合物分离性能的 GO/NH2-Fe3O4 纳滤膜。NH2-Fe3O4 不仅作为刚性球形纳米间隔物来调节 GO 层间距，而且作为交联剂来提高 GO 膜在水中的稳定性。FTIR、XRD、SEM、zeta 电位和接触角用于分析所制备膜的化学成分和形态。系统地研究了嵌入的 NH2-Fe3O4 纳米粒子对 GO/NH2-Fe3O4 膜的整体性能的影响。所得到的 NH2-Fe3O4 负载量为 8 wt% 的膜具有高达 78 Lm-2 h-1 的高水通量，是纯 GO 膜的 4.8 倍。此外，这种膜还显示出高刚果红截留率 (94%) 和低 NaCl 截留率 (~15%)，使膜有望用于染料/盐混合物分离。所得到的 NH2-Fe3O4 负载量为 8 wt% 的膜具有高达 78 Lm-2 h-1 的高水通量，是纯 GO 膜的 4.8 倍。此外，这种膜还显示出高刚果红截留率 (94%) 和低 NaCl 截留率 (~15%)，使膜有望用于染料/盐混合物分离。所得到的 NH2-Fe3O4 负载量为 8 wt% 的膜具有高达 78 Lm-2 h-1 的高水通量，是纯 GO 膜的 4.8 倍。此外，这种膜还显示出高刚果红截留率 (94%) 和低 NaCl 截留率 (~15%)，使膜有望用于染料/盐混合物分离。