Two-dimensional (2D) nanosheets have emerged as promising functional materials owing to their atomic thickness and unique physical/chemical properties. By using 2D nanosheets as building blocks, diverse kinds of two-dimensional nanochannel membranes (2DNCMs) are being actively explored, in which mass transport occurs in the through-plane and interlayer channels of 2D nanosheets. The rational construction and physical/chemical microenvironment regulation of nanochannels are of vital significance for translating these 2D nanosheets into molecular separation membranes and ionic separation membranes. Focusing on the recent advances of 2DNCMs, in this review, various porous/nonporous 2D nanosheets and their derived nanochannels are first briefly introduced. Then we discuss the emerging top-down and bottom-up methods to synthesize high-quality 2D nanosheets and to prepare high-performance 2DNCMs. As the major part of this review, we focus on three types of nanochannels, which are based on nonporous nanosheets, intrinsically porous nanosheets and perforated nanosheets. The strategies for regulating the physical and chemical microenvironments in the nanochannels are emphasized. The representative applications of 2DNCMs in molecular separations (gas separation, liquid separation) and ionic separations are presented. Finally, the current challenges and future perspectives are highlighted.

中文翻译：

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用于分子和离子分离的二维纳米通道膜

二维（2D）纳米片由于其原子厚度和独特的物理/化学性质而成为有前途的功能材料。通过使用2D纳米片作为构建基块，正在积极探索各种二维纳米通道膜（2DNCM），其中在2D纳米片的贯穿平面和层间通道中发生质量传输。纳米通道的合理构建和物理/化学微环境调节对于将这些二维纳米片转化为分子分离膜和离子分离膜至关重要。着眼于2DNCM的最新进展，在本综述中，首先简要介绍了各种多孔/无孔2D纳米片及其衍生的纳米通道。然后，我们讨论了新兴的自上而下和自下而上的方法，以合成高质量的2D纳米片并制备高性能的2DNCM。作为本综述的主要部分，我们重点介绍三种类型的纳米通道，它们基于无孔纳米片，固有多孔纳米片和多孔纳米片。强调了调节纳米通道中物理和化学微环境的策略。介绍了2DNCM在分子分离（气体分离，液体分离）和离子分离中的代表性应用。最后，重点介绍了当前的挑战和未来的前景。强调了调节纳米通道中物理和化学微环境的策略。介绍了2DNCM在分子分离（气体分离，液体分离）和离子分离中的代表性应用。最后，重点介绍了当前的挑战和未来的前景。强调了调节纳米通道中物理和化学微环境的策略。介绍了2DNCM在分子分离（气体分离，液体分离）和离子分离中的代表性应用。最后，重点介绍了当前的挑战和未来的前景。