Acta Chim. Sinica ›› 2016, Vol. 74 ›› Issue (12): 980-983.DOI: 10.6023/A16100562 Previous Articles     Next Articles

Special Issue: 聚集诱导发光



荣根兰a, 张心怡a, 胥燕a, 张跃钢a,b   

  1. a 中国科学院苏州纳米技术与纳米仿生研究所国际实验室 苏州 215123;
    b 清华大学物理系 北京 100084
  • 投稿日期:2016-10-24 发布日期:2016-12-05
  • 通讯作者: 张跃钢
  • 基金资助:


In-situ TEM Study of the Liquid-Phase Reaction of Ag Nanowires with a Sulfur Solution

Rong Genlana, Zhang Xinyia, Xu Yana, Zhang Yueganga,b   

  1. a i-Lab, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123;
    b Department of Physics, Tsinghua University, Beijing 100084
  • Received:2016-10-24 Published:2016-12-05
  • Supported by:

    Project supported by the National Natural Science Foundation of China (No. 21433013) and the CAS-DOE Joint Research Program (No. 121E32KYSB20150004).

Using transmission electron microscopy (TEM) to directly observe a dynamic chemical reaction process in liquid-phase environment is a big challenge because it is difficult to keep liquid reactants under vacuum.In this work,we reported a liquid-based cell that enables in-situ observation of a solution reaction process under TEM.The novel liquid cell design not only realizes the self-alignment of top/bottom windows,but also achieves an adjustable liquid layer thickness down to nanometer scale.The cell consists of top and bottom frames,both of which are fabricated from silicon wafers using conventional micro-fabrication techniques.The transparent observation windows are made of silicon nitride (SiNx) membranes.In a typical assembling process,an ethanol solution containing silver nanowires and an ethanol solution containing saturated sulfur were sequentially dropped into the liquid tank of the bottom-frame of a liquid cell by using 1 mL syringe.Then,the liquid tank was covered by the top-frame with a window direction of 90 degrees,and an epoxy was used to seal the edge between the top-frame and bottom-frame.Using this assembled liquid cell,we performed in-situ TEM observation of the chemical reaction between Ag nanowires and sulfur in ethanol solution.Additional ex-situ X-ray diffraction (XRD) and Raman spectroscopy were also performed to study the reaction intermediates and final products.Instead of a simple reaction process in which sulfur diffuses into Ag to form the final product of Ag2S,we found that the real reaction process involves the formation of a soluble intermediate phase (Ag2S4),which led to a partial dissolution of Ag nanowires in ethanol solution during reaction.These results well demonstrate that the in-situ TEM technique is a powerful tool to reveal the "real" chemical reaction mechanism.The experimental technique developed here could also be used to study a broad range of dynamic phenomena in liquid environment.

Key words: in-situ transmission electron microscopy (TEM), liquid-based cell, Ag-S reaction process, silver polysulfide, Raman spectrum