Confinement and Interface Effects on Radiolysis in Liquid-Phase TEM Probed by Palladium Nanocrystal Etching.

Liquid-phase transmission electron microscopy (LPTEM) enables real-time visualization of nanoscale dynamics in electrochemical, biological, and catalytic reactions. However, accelerated electrons employed as probes can perturb the chemical environment through electron-liquid interactions, thereby complicating reliable data acquisition and interpretation. Although these interactions have been studied based on kinetic modeling of water radiolysis, a comprehensive understanding of the influence of interfaces and confinement within microfluidic liquid cells remains less understood. Prior γ-irradiation and electron-beam studies have shown that adsorbed water on solid-liquid interfaces can dramatically modify radical yields, yet the effect of specific interfaces in liquid cells on radiolysis has been less understood. Herein, we reveal effects at interfaces and their influence on water radiolysis by liquid-cell interface engineering using radiolysis-driven oxidative etching of palladium nanocubes as a probing system. Complementary density functional theory calculations show that graphene coatings suppress interfacial water dissociation and electron transfer, thereby modulating beam interaction pathways.