Controlling the radical-induced redox chemistry inside a liquid-cell TEM

Area of Science:

• Materials Science
• Chemistry
• Nanotechnology

Background:

• Liquid-Cell Transmission Electron Microscopy (LCTEM) enables observation of nanoscale materials in solution.
• Electron beam-induced solvent radiolysis can significantly alter material dynamics.
• Understanding radiolysis is crucial for accurate nanomaterial studies in LCTEM.

Purpose of the Study:

• To develop a comprehensive model for beam-driven solvent radiolysis in LCTEM.
• To quantify the interplay between radiolysis species and nanomaterials.
• To enable new strategies for studying redox-driven dynamics in functional nanomaterials.

Main Methods:

• Developed a comprehensive radiolysis model incorporating electron-dose rate, solvent temperature, gas concentrations (H2, O2), and pH.
• Utilized kinetic models to simulate material-specific radical-induced redox reactions.
• Employed Temperature/Dose-rate Redox potential (TDR) diagrams for visualizing equilibrium concentration ratios.

Main Results:

• The model successfully simulates radical-induced redox reactions for nanomaterials, exemplified by gold (Au) nanoparticles.
• TDR diagrams predict Au nanoparticle precipitation/dissolution regions based on temperature and dose rate.
• The models were validated against gamma radiation data and experimental LCTEM observations.

Conclusions:

• The study presents a holistic approach to radiolysis and radical-induced redox chemistry in LCTEM.
• The developed models provide quantitative insights into radiolysis effects on nanomaterials.
• This work facilitates more accurate and strategic research on solvated nanomaterials using LCTEM.