Visualizing Millisecond Atomic Dynamics of Nanocrystals in Liquid

TL;DR

This study employs millisecond liquid cell electron microscopy combined with deep learning to visualize and analyze atomic-scale dynamics of gold nanocrystals in reactive liquids, revealing reversible structural fluctuations that impact nanomaterial stability.

Contribution

It introduces a novel approach for real-time atomic-resolution imaging of nanocrystals in liquids, overcoming previous temporal limitations and uncovering dynamic behaviors affecting nanomaterial properties.

Findings

Reversible fluctuations in nanocrystal crystallinity depend on chemical environment.

Transient atomic structures influence dissolution and grain boundary relaxation.

Millisecond imaging captures dynamics previously unobservable with conventional methods.

Abstract

Atomic structures of nanomaterials are inherently dynamic, continuously reshaped through interactions with chemical species and external stimuli. Such dynamics are further amplified as the size and dimensionality of nanomaterials are reduced. Despite advances in analytical methods, it remains challenging to capture structural dynamics of nanomaterials in reactive environments with both atomic spatial resolution and commensurate temporal resolution. Here, we directly visualize atomic-scale dynamics of gold (Au) nanocrystals in reactive liquid environments with millisecond-speed liquid cell electron microscopy (EM) and deep-learning denoising. We uncover reversible fluctuations in local crystallinity of Au nanocrystals dependent on the surrounding chemical environment. These transient fluctuations, driven by interactions at nanocrystal-liquid interfaces, critically influence dissolution kinetics and grain boundary relaxation. By overcoming the spatiotemporal limitations in conventional liquid cell EM, our findings provide insights into how transient nanoscale structures dictate the stability and reactivity of nanomaterials.