质谱法精确测量二维材料亚纳米孔的气体透过率  

Accurate measurement of gas permeation through sub-nanopores of two-dimensional materials by mass spectrometry

作　　者：胡奎 肖龙腾 张光杰 裘晓辉[1,2] Kui Hu;Longteng Xiao;Guangjie Zhang;Xiaohui Qiu(Chinese Academy of Sciences Key Laboratory of Standardization and Measurement for Nanotechnology,National Center for Nanoscience and Technology,Beijing100190,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]国家纳米科学中心,中国科学院纳米标准与检测重点实验室,北京100190 [2]中国科学院大学,北京100049

出　　处：《科学通报》2023年第32期4425-4432,共8页Chinese Science Bulletin

基　　金：国家自然科学基金(21721002);中国科学院战略性先导科技专项(B类)(XDB36000000)资助。

摘　　要：二维材料多孔膜因具有原子级厚度,有望突破传统分离膜的选择性和透过率限制,实现高效物质分离.二维材料中的亚纳米孔具有不同于经典理论所描述的分子运输行为,精确测量二维材料亚纳米孔对气体分子的透过率是研究其独特分子输运性质的前提.我们发展了基于超高真空和质谱探测技术的极微量气体分子透过率的测量方法,实现了二维材料亚纳米孔的气体分子透过率的高灵敏和实时测量.超高真空系统有效降低了测量的背景信号,通过优化质谱探测的测量灵敏度,系统对气体分子的测量下限达到9×10~8个/s,与已报道的测量方法相比提高了2个数量级.我们测量了单层二硫化钼的亚纳米孔对He、Ne、Ar的透过率,观察到了亚纳米孔的分子筛分特性.该方法为研究二维材料亚纳米孔的气体分子输运机制提供了有效手段.Mass transport at the sub-nanometre scale plays a key role in systems such as catalysis,energy generation and storage,chemical sensing,and molecular separation.Highly efficient biological channels in living organisms have inspired the design of artificial channels with similar or even higher mass transport efficiency.The membranes function by forming a barrier between the two phases,restricting the movement of some molecules while letting others through.The mass transport rate of the membrane is inversely proportional to thickness,and theoretically,the membrane with atomic layer thickness can produce the maximum flux with the minimum energy cost.Meanwhile,the pore size can be precisely manipulated within sub-nanometer size for molecular separation,such as gas separation.So,sub-nanopores in graphene and other atomically thin two-dimensional materials are regarded as highly promising membrane materials for highperformance substance separation due to their atomic thickness,large-scale synthesizability,excellent mechanical strength,and chemical stability.Sub-nanopores membranes base on two-dimensional(2D)materials with atomic-scale thickness are expected to break the trade-off between selectivity and permeation of conventional separation membranes,resulting in efficient separation.The mass transport mechanism of sub-nanopores in 2D materials is different from that predicted by classical theories,and the mechanism is yet to be understood to design efficient separation membranes.The gas permeation reflects the permeability of membrane materials and is an important parameter describing gas transport characteristics.Studying the gas permeation of membrane materials can not only provide basic information about the materials,such as pore size and distribution,but also further understand the influence of gas adsorption and diffusion on the mechanism of gas transport.Although some theoretical studies have predicted the molecular transport properties of single-layer sub-nanopores,experimental research is still scarce,and ther

关 键 词：气体透过率 质谱 二维材料 亚纳米孔 

分 类 号：TB383.1[一般工业技术—材料科学与工程] O657.63[理学—分析化学]