Non-thermal Reactions at Surfaces and Interfaces, and in Model Aqueous Systems
EMSL Project ID
49144
Abstract
Energetic processes at surfaces and interfaces are important in fields such as radiation chemistry, radiation biology, waste processing, and advanced materials synthesis. Low-energy electrons (<100 eV) frequently play a dominant role in these energetic processes since the higher energy primary particles produce numerous low-energy, chemically active, secondary electrons. In addition, the presence of surfaces or interfaces modifies the physics and chemistry compared to what occurs in the bulk. We will use quadrupole mass spectroscopy, Fourier transform infrared spectroscopy (FTIR), and other ultra-high vacuum surface science techniques to investigate energetic, electron-stimulated reactions at surfaces and interfaces, in nanoscale materials, and in thin molecular solids. We will also explore the structure of water near interfaces since it plays a crucial role in the thermal and non-thermal chemistry occurring there. A key element of the approach is to use a tunable, mono-energetic electron beam to unravel the complex chemistry that results from the simultaneous release of electrons with a broad range of energies by the primary excitation events associated with ionizing radiation. This work addresses several important issues, including understanding the relative importance of the primary excitation source compared to the secondary electrons it produces, the relationship between water's structure near an interface and the non-thermal reactions occurring there, and energy transfer and new reaction pathways at surfaces and interfaces.
Project Details
Start Date
2015-10-09
End Date
2018-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Team Members
Related Publications
Mu R, AP Dahal, Z Wang, Z Dohnalek, GA Kimmel, NG Petrik, and IV Lyubinetsky. 2017. "Adsorption and Photodesorption of CO from Charged Point-Defects on TiO2(110)." Journal of Physical Chemistry Letters 8(18):4565-4572. doi:10.1021/acs.jpclett.7b02052
Petrik N.G., and G.A. Kimmel. 2018. "Electron-stimulated reactions in nanoscale water films adsorbed on (alpha)-Al2O3(0001)." Physical Chemistry Chemical Physics. PCCP 20, no. 17:11634-11642. PNNL-SA-132648. doi:10.1039/C8CP01284A
Petrik N.G., P.I. Huestis, J. Laverne, A. Aleksandrov, T.M. Orlando, and G.A. Kimmel. 2018. "Molecular water adsorption and reactions on -Al2O3(0001) and -alumina particles." Journal of Physical Chemistry C 122, no. 17:9540-9551. PNNL-SA-132650. doi:10.1021/acs.jpcc.8b01969
Xu Y, CJ Dibble, NG Petrik, RS Smith, AG Joly, RG Tonkyn, BD Kay, and GA Kimmel. 2016. "A nanosecond pulsed laser heating system for studying liquid and supercooled liquid films in ultrahigh vacuum." PNNL-SA-115728, Pacific Northwest National Laboratory, Richland, WA.