Related Experiment Video
Updated: Feb 23, 2026
10:59
Author Spotlight: Tracking Electrochemistry on Single Nanoparticles with Surface-Enhanced Raman Scattering Spectroscopy and Microscopy
Published on: May 12, 2023
3.5K
Tracking the restructuring of oxidized silver-indium nanoparticles under a reducing atmosphere by environmental HRTEM
Julien Ramade1, Cyril Langlois, Michel Pellarin
1Univ. Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France. emmanuel.cottancin@univ-lyon1.fr.
Nanoscale
|September 7, 2017
Summary
The structural evolution of silver-indium nanoparticles was observed in real-time. High hydrogen pressure and temperature lead to stable silver-indium alloys, while intermediate conditions form Janus structures.
Area of Science:
- Materials Science
- Nanotechnology
- Surface Science
Background:
- Multimetallic nano-alloys exhibit dynamic structural and property changes in reactive environments.
- Understanding these evolutions is critical for applications in gas sensing and catalysis.
- Oxidized silver-indium (Ag25In75) nanoparticles were studied to reveal their behavior under varying conditions.
Purpose of the Study:
- To investigate the real-time structural evolution of oxidized Ag25In75 bimetallic nanoparticles.
- To understand the influence of hydrogen partial pressure (PH) and substrate temperature (Ts) on nanoparticle transformation.
- To elucidate the mechanisms governing nanoparticle reorganization in reactive atmospheres.
Main Methods:
- Environmental transmission electron microscopy (E-TEM) was employed to achieve atomic resolution.
- In-situ observations were conducted under controlled hydrogen partial pressures and substrate temperatures.
- Laser vaporization was used for nanoparticle synthesis, followed by air transfer.
Main Results:
- Initially, Ag25In75 nanoparticles present an indium-oxide shell around a silver-rich alloy core.
- At high PH and Ts, indium oxide reduction occurs, followed by indium atom diffusion/melting, leading to a growth of the silver-indium alloy core.
- Intermediate PH and Ts conditions promote the formation of Janus structures, transitioning between core-shell and alloyed states.
- The resulting silver-indium alloys demonstrate high stability and resistance to oxidation.
Conclusions:
- High-resolution E-TEM is effective for unraveling nanoparticle reorganization mechanisms.
- Thermodynamic driving forces, including alloying and interface energies, govern the observed structural transformations.
- The study reveals distinct structural outcomes (core-shell, Janus, alloy) based on environmental conditions, offering insights for nanomaterial design.
