Abstract:

Although the recently emerging two-dimensional membrane materials show significantly improved separation performance compared to traditional polymer-based membrane materials. However, the molecular mass transfer in a two-dimensional membrane needs to pass through stacked two-dimensional channels, and the transmission path is long, which limits the further increase of the permeation flux of the two-dimensional membrane. This study proposed the regulation of 2D membranes using one-dimensional metal-organic framework nanowires to achieve the increasing fluxes without sacrificing rejections. The completion of such a strategy is based on the intercalation of MoS₂ lamellar membranes by the Zn-BTC nanowires to gain Zn-BTC/MoS₂ composite membranes. The Zn-BTC/MoS₂ composite membranes show 2—6 times higher organic solvent permeation fluxes than the MoS₂ membrane and the acetone flux is up to 3562 L·m^-2·h^-1·bar^-1. Simultaneously, such composite membranes hold the same promising rejection ability as the MoS₂ membrane, accomplishing 100% rejections towards dye molecules with sizes above 0.42 nm.

Key words: membrane, nanofiltration, nanowire, Zn-BTC/MoS₂ composite membranes, separation

摘要：

尽管最近兴起的二维膜材料相较于传统的聚合物基膜材料呈现出明显提升的分离性能。但是二维膜中分子传质需要经过层层堆积的二维通道，传输路径较长，限制了二维膜渗透通量的进一步提升。提出用一维金属有机框架纳米线来调控二维膜实现通量提升，同时不降低分离能力。该策略的实现是通过Zn-BTC纳米线插层MoS₂层级膜，制备了Zn-BTC/MoS₂复合膜。该复合膜的有机溶剂通量比MoS₂二维膜提高了2~6倍，丙酮渗透通量高达3562 L·m^-2·h^-1·bar^-1。同时该复合膜保持了与MoS₂膜同等优异的筛分能力，对于尺寸大于0.42 nm的染料分子，可以实现100%截留。

关键词: 膜, 纳滤, 纳米线, Zn-BTC/MoS₂复合膜, 分离