Probing the oxidative etching induced dissolution of palladium nanocrystals in solution by liquid cell transmission electron microscopy.
A microscopic study of dissolution process of nanocrystals, an opposite while functioning cooperatively with growth in many cases, is an essential issue in variety aspects of research on nanocrystals. In this work, an in situ study of the dynamic dissolution process of palladium nanocrystals by liquid cell transmission electron microscope (TEM) is presented. The effective critical size (Rcritical) for monodispersed nanocrystals is determined to be about 5nm in the experimental condition of this article. When the size of nanocrystal is above Rcritical, the dissolution rate (dr/dt) is nearly a constant. For the nanocrystal sizing below Rcritical, the dissolution rate (dr/dt) increases with the decrease of the nanocrystal radius r, indicating that high equilibrium solubility must be taken into account in the dissolution rate of small nanocrystals in solution. It is found that the aggregation kinetics and confinement effect between adjacent nanocrystals have effects on the dissolution rate during the reaction, and it has been analyzed in details and discussed in terms of the underlying physics involved. Lastly, the effects of electron beam-water interaction and the iron (III) agents on the oxidative etching are also compared.
State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, PR China.
Yingying
Y
Jiang
State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, PR China.
Guomin
G
Zhu
State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, PR China.
Ganxing
G
Dong
College of Electronic Engineering, South China Agricultural University, Guangzhou, Guangdong 510642, PR China; State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, PR China.
Fang
F
Lin
State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, PR China.
Hui
H
Zhang
Department of Physics, University of York, Heslington, York, YO10 5DD, United Kingdom; State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, PR China.
Jun
J
Yuan
State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, PR China.
Ze
Z
Zhang
State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, PR China.. Electronic address: chhjin@zju.edu.cn.
Chuanhong
C
Jin
In situ; Liquid cell TEM; Oxidative etching; Pd nanocrystal