Abstract
Radiation driven reactions at mineral/air interfaces are important to the chemistry of the atmosphere, but experimental constraints (e.g. simultaneous irradiation, in situ observation, and environmental control) leave process understanding incomplete. Using a custom atomic force microscope equipped with an integrated X-ray source, transformation of potassium bromide surfaces to potassium nitrate by air radiolysis species was followed directly in situ at the nanoscale. Radiolysis initiates dynamic step edge dissolution, surface composition evolution, and ultimately nucleation and heteroepitaxial growth of potassium nitrate crystallites mediated by surface diffusion at rates controlled by adsorbed water. In contrast to in situ electron microscopy and synchrotron-based imaging techniques where high radiation doses are intrinsic, our approach illustrates the value of decoupling irradiation and the basis of observation.
| Original language | English |
|---|---|
| Article number | 49 |
| Journal | Communications Chemistry |
| Volume | 4 |
| Issue number | 1 |
| DOIs | |
| State | Published - Dec 2021 |
| Externally published | Yes |
Funding
Development of the RadAFM instrument was supported as part of the Laboratory Directed Research and Development Nuclear Processing Science Initiative (NPSI) at the Pacific Northwest National Laboratory (PNNL). KMR acknowledges support for his role in data interpretation and manuscript development as part of IDREAM (Interfacial Dynamics in Radioactive Environments and Materials), an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE), Office of Science (SC), Office of Basic Energy Sciences (BES). A portion of the research was performed in the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the DOE Office of Biological and Environmental Research and located at PNNL. PNNL is a multiprogram national laboratory operated for the DOE by Battelle Memorial Institute under Contract No. DE‐AC05‐76RL0‐1830. We gratefully acknowledge Sue B. Clark and Reid A. Peterson for their support of the radAFM development.