Dealloying Kinetics of AgAu Nanoparticles by in Situ Liquid-Cell Scanning Transmission Electron Microscopy

Pan Liu, Qing Chen, Yoshikazu Ito, Jiuhui Han, Shufen Chu, Xiaodong Wang, Kolan Madhav Reddy, Shuangxi Song, Akihiko Hirata, Mingwei Chen

Research output: Contribution to journalArticle

Abstract

Understanding the formation and evolution of bicontinuous nanoporous structure during dealloying has been one of the most challenging subjects of dealloying research. However, previous in situ investigations either suffer from insufficient spatial resolution (e.g., X-ray tomography) or lack morphology visualization and mass information (e.g., scanning tunneling microscopy). In this work, we report the kinetics of the whole course of dealloying by utilizing liquid-cell aberration-corrected scanning transmission electron microscopy. With Z-contrast imaging analysis, the in situ sub-nanoscale characterization reveals two new phenomena, an initial period of dealloying indicative of an initial length scale for bulk dealloying and a large volume shrinkage in a nanoscale alloy precursor. We explain the particle-size-dependent volume shrinkage with the formation of a dense shell and quantify the dependence with a simple geometric model. These insights into the mechanisms of dealloying will enable deliberate designs of nanoporous structures.

Original languageEnglish
Pages (from-to)1944-1951
Number of pages8
JournalNano Letters
Volume20
Issue number3
DOIs
Publication statusPublished - 2020 Mar 11
Externally publishedYes

Keywords

  • Dealloying
  • In situ liquid-cell STEM
  • Initial length scale
  • Nanoporous gold
  • Volume shrinkage

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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    Liu, P., Chen, Q., Ito, Y., Han, J., Chu, S., Wang, X., Reddy, K. M., Song, S., Hirata, A., & Chen, M. (2020). Dealloying Kinetics of AgAu Nanoparticles by in Situ Liquid-Cell Scanning Transmission Electron Microscopy. Nano Letters, 20(3), 1944-1951. https://doi.org/10.1021/acs.nanolett.9b05216