Fast Tomography for 3D Characterization of Nanomaterial Dynamics in Liquid-Phase Transmission Electron Microscopy

Electron tomography (ET) provides three-dimensional (3D) materials morphology at a nanometer to sub-angstrom resolution. However, in ET, besides the necessary exposure time needed for imaging at each tilt angle, the tilting process contributes the most to the acquisition time due to the necessary correction of sample drift and refocusing. As a result, the typical acquisition time of ET ranges from tens of minutes to a few hours, which not only accumulates damage on beam-sensitive samples (e.g., protein and polymer), but also limits the technique to the characterization of static samples with no dynamics. In this work, we achieve the fast ET acquisition within one minute and apply it to characterize reaction of nanoparticles in graphene liquid cell, where the intriguing 3D morphology change dynamics was well-captured. Kinetic Monte Carlo simulation reveal the crucial factors determining the etching trajectory. We anticipate this work as a universal platform to provide understandings of nanoscale reactions in liquid environments across various nanomaterials, extending from metallic nanoparticles to quantum dots, polymers, and proteins.