Galvanic Transformation Dynamics in Heterostructured Nanoparticles

Jingshan S. Du, Kun He, Yaobin Xu, Carolin B. Wahl, David D. Xu, Vinayak P. Dravid*, Chad A. Mirkin*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

7 Scopus citations

Abstract

Corrosion is a significant problem for the stability of structural metals and potentially for functional nanomaterials in operating environments. When two metals with different electrochemical potentials form a junction, galvanic corrosion occurs, resulting in the sacrificial dissolution of the metal with a higher oxidation potential (lower electrode potential). Here, it is shown that bimetallic hetero-nanostructures composed of phase-segregated metals undergo galvanic corrosion in aqueous environments. Such selective etching of the sacrificial metal in heterojunction particles leads to the formation of unusual and kinetically stabilized half-spheroid particles. By using a fluid cell and in situ scanning transmission electron microscopy, a two-stage corrosion process can be observed where the Cu experiences a fractal breakdown before the Ag corrodes due to the lack of a protective oxide layer. However, when treated with a mild Ar plasma, the stability of these structures against corrosion is enhanced due to the conversion of the amorphous native oxide to a denser, thin layer of CuO on the Cu surface. Taken together, this work highlights the importance of considering the effects of galvanic corrosion on the stability of multicomponent nanoparticles, and it shows how mass transport in a nanoscale system is influenced by redox processes.

Original languageEnglish (US)
Article number2105866
JournalAdvanced Functional Materials
Volume31
Issue number46
DOIs
StatePublished - Nov 10 2021

Keywords

  • corrosion
  • galvanic
  • in situ transmission electron microscopy
  • multimetallic
  • nanoparticles

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • General Chemistry
  • General Materials Science
  • Electrochemistry
  • Biomaterials

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