Single-particle mapping of nonequilibrium nanocrystal transformations

Area of Science:

• * Materials Science and Nanotechnology
• * Physical Chemistry

Background:

• * Understanding nonequilibrium species is crucial for mechanistic insight into chemical reactions.
• * Existing methods for probing transient molecular species are insufficient for nanomaterials.

Purpose of the Study:

• * To develop and apply techniques for observing and analyzing short-lived intermediate structures in nanomaterials.
• * To investigate the shape evolution of anisotropic gold nanostructures during oxidative etching.

Main Methods:

• * Utilized a graphene liquid cell to create a controlled redox environment for oxidative etching.
• * Monitored the shape evolution of individual anisotropic gold nanostructures in real-time.
• * Employed Monte Carlo simulations to rationalize observed nanocrystal morphologies.

Main Results:

• * Observed and structurally analyzed short-lived, nonequilibrium nanocrystal intermediates.
• * Connected high-energy nanocrystal shapes to the formation of kinetically stabilized surface features.
• * Demonstrated the capability to probe transient nanoscale species at the single-particle level.

Conclusions:

• * The study establishes a method for observing nonequilibrium nanomaterials, advancing fundamental understanding.
• * Insights into reaction trajectories of gold nanostructures reveal mechanisms of surface feature development.
• * Highlights the necessity of single-particle level tools for studying dynamic nanoscale processes.