Acta Phys. -Chim. Sin. ›› 2017, Vol. 33 ›› Issue (3): 458-463.doi: 10.3866/PKU.WHXB201701041

• COMMUNICATION • Previous Articles     Next Articles

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)

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