Challenges associated with in-situ TEM in environmental systems: The case of silver in aqueous solutions

This work characterizes the effects of an electron beam on inducing microstructural evolution in Ag during environmental transmission electron microscopy. Two different processes, dissolution of Ag and deposition of Ag under the beam, were observed under different experimental conditions. The former primarily results from ionization induced by the primary beam and the latter primarily results from reduction of Ag+ ions in solution by secondary electrons generated in the substrate. The relative rates vary with the activity of silver in solution and beam current density. A simple model based on chemical kinetics describes the general response of the system as a function of beam current density and solution composition. ► Effects of the electron beam on silver in an aqueous environment of varying silver activity were investigated. ► Dissolution of Ag primarily results from ionization induced by the primary beam. ► Deposition of Ag primarily results from reduction of Ag+ ions in solution by secondary electrons generated in the substrate. ► Relative rates vary with the activity of silver in solution.