物理化学学报 >> 2017, Vol. 33 >> Issue (3): 458-463.doi: 10.3866/PKU.WHXB201701041

通讯 上一篇    下一篇

用原位液体池透射电镜技术表征金属钯在球形金纳米颗粒表面的异质沉积

周晓琴1,3,张辉3,张泽3,陈新1,2,*(),金传洪3,*()   

  1. 1 华东理工大学材料科学与工程学院,超细材料制备与应用教育部重点实验室,上海市先进聚合物材料重点实验室,上海200237
    2 中国科学院上海微系统与信息技术研究所,信息功能材料国家重点实验室,上海200050
    3 浙江大学材料科学与工程学院,硅材料国家重点实验室,杭州310027
  • 收稿日期:2016-11-25 发布日期:2017-03-07
  • 通讯作者: 陈新,金传洪 E-mail:xinchen73@ecust.edu.cn;chhjin@zju.edu.cn
  • 基金资助:
    上海市重点学科项目(B502);上海市重点实验室项目(08DZ2230500);上海市科学技术委员会项目(11nm0507000);信息功能材料国家重点实验室开放课题(SKL201306);国家自然科学基金(51222202)

Characterization of Heterostructural Palladium Deposition on Spherical Gold Nanoparticles by In situ Liquid Cell Transmission Electron Microscopy

Xiao-Qin ZHOU1,3,Hui ZHANG3,Ze ZHANG3,Xin CHEN1,2,*(),Chuan-Hong JIN3,*()   

  1. 1 Key Laboratory for Ultrafine Materials of Ministry of Education, Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
    2 State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, P. R. China
    3 State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, P. R. China
  • Received:2016-11-25 Published:2017-03-07
  • Contact: Xin CHEN,Chuan-Hong JIN E-mail:xinchen73@ecust.edu.cn;chhjin@zju.edu.cn
  • Supported by:
    the Shanghai Leading Academic Discipline Project, China(B502);Shanghai Key Laboratory Project, China(08DZ2230500);Shanghai Committee of Science and Technology Support Project, China(11nm0507000);State Key Laboratory of Functional Materials for Informatics Open Project, China(SKL201306);National Natural Science Foundation of China(51222202)

摘要:

采用原位液体池透射电镜技术,在扫描透射电子显微镜(STEM)中,实时观察溶液中金属钯(Pd)在金(Au)纳米颗粒及团簇周围的异质沉积过程。通过对该动态过程的定量分析,结合高分辨透射电子显微镜(HRTEM)对样品进行形貌与结构表征,研究异质沉积的机理。结果表明,电子束辐照下Au-Pd异质结构纳米颗粒的形成存在两种主要机制:第一种机制中,Pd在Au纳米颗粒表面的生长是以岛状沉积开始,随着时间推移,出现Pd岛的结构弛豫和沿着Au颗粒表面的迁移扩展。伴随Pd的不断沉积和弛豫,Au-Pd复合颗粒的外接圆直径表现为震荡生长,而Au表面的Pd覆盖率显示出随时间单调增加的趋势。第二种机制中,由于Pd单体在Au纳米颗粒上的沉积位点有限,使部分被还原的Pd在Au颗粒以外区域进行同质形核与生长形成Pd团簇,之后再与Au颗粒上的Pd岛合并。进一步的结果分析显示,Au颗粒外围的Pd沉积体为多晶结构,由随机取向的Pd纳米晶粒构成。

关键词: 原位液体池透射电镜, 贵金属纳米晶, 异质沉积, 结构弛豫, 表面迁移

Abstract:

We report an in situ liquid cell scanning transmission electron microscopy (STEM) study of the heterogeneous deposition of palladium (Pd) on spherical gold (Au) nanoparticles in solution. The dynamic processes observed here revealed different behaviors of Pd deposition on Au nanoparticles. Under irradiation by an energetic electron beam, Pd was reduced and selectively deposited on Au nanoparticles through the island deposition mode. The deposition processes were accompanied with structural relaxation and surface migration of the Pd islands, and the size of the Au-Pd composite particles showed oscillatory growth behavior. In contrast, the Pd coverage on Au increased monotonically. In addition, we also captured the formation of Pd clusters through homogeneous nucleation and growth, and the subsequent coalescence of Pd clusters with islands on the Au-Pd heterostructures. The associated heterogeneous deposition mechanisms were proposed and quantitatively analyzed. The shapes and structures of the Au-Pd composite particles were characterized by highresolution transmission electron microscopy (HRTEM), which revealed the deposited Pd on the Au spherical nanoparticles was polycrystalline and contained several Pd crystallites with random orientations. The results presented here will serve as an important reference to understand heterogeneous growth in liquid solutions.

Key words: In situ liquid cell TEM, Noble metal nanocrystal, Heterogeneous deposition, Structure relaxation, Surface migration

MSC2000: 

  • O648