1
|
Ghandi K, Landry C, Du T, Lainé M, Saul A, Le Caër S. Influence of confinement on free radical chemistry in layered nanostructures. Sci Rep 2019; 9:17165. [PMID: 31748626 PMCID: PMC6868163 DOI: 10.1038/s41598-019-52662-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 10/18/2019] [Indexed: 11/08/2022] Open
Abstract
The purpose of the present work was to study how chemical reactions and the electronic structure of atoms are affected by confinement at the sub-nanometer scale. To reach this goal, we studied the H atom in talc, a layered clay mineral. Talc is a highly 2D-confining material with the width of its interlayer space close to angstrom. We investigated talc with a particle accelerator-based spectroscopic method that uses elementary particles. This technique generates an exotic atom, muonium (Mu), which can be considered as an isotope of the H atom. Moreover, the technique allows us to probe a single atom (H atom) at any time and explore the effects of the layered clay on a single ion (proton) or atom. The cation/electron recombination happens in two time windows: one faster than a nanosecond and the other one at longer than microseconds. This result suggests that two types of electron transfer processes take place in these clay minerals. Calculations demonstrated that the interlayer space acts as a catalytic surface and is the primary location of cation/electron recombination in talc. Moreover, the studies of the temperature dependence of Mu decay rates, due to the formation of the surrogate of H2, is suggestive of an "H2" formation reaction that is thermally activated above 25 K, but governed by quantum diffusion below 25 K. The experimental and computational studies of the hyperfine coupling constant of Mu suggest that it is formed in the interlayer space of talc and that its electronic structure is extremely changed due to confinement. All these results imply that the chemistry could be strongly affected by confinement in the interlayer space of clays.
Collapse
Affiliation(s)
- Khashayar Ghandi
- University of Guelph, Department of chemistry, Guelph, ON, N1G 2W1, Canada.
| | - Cody Landry
- University of Guelph, Department of chemistry, Guelph, ON, N1G 2W1, Canada
| | - Tait Du
- Université de Sherbrooke, Faculté de médecine, Sherbrooke, QC, J1H 5N4, Canada
| | - Maxime Lainé
- LIONS, NIMBE, CEA, CNRS, Université Paris Saclay, CEA Saclay, F-91191, Gif-sur-Yvette, Cedex, France
| | - Andres Saul
- Aix-Marseille University, CINaM-CNRS UMR 7325 Campus de Luminy, F-13288, Marseille, Cedex 9, France
| | - Sophie Le Caër
- LIONS, NIMBE, CEA, CNRS, Université Paris Saclay, CEA Saclay, F-91191, Gif-sur-Yvette, Cedex, France
| |
Collapse
|
2
|
Liu G, Landry C, Ghandi K. Prediction of rate constants of important chemical reactions in water radiation chemistry in sub and supercritical water – non-equilibrium reactions. CAN J CHEM 2018. [DOI: 10.1139/cjc-2017-0315] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The rate constants for reactions involved in the radiolysis of water under relevant thermodynamic conditions in supercritical water-cooled reactors are estimated for inputs in simulations of the radiation chemistry in Generation IV nuclear reactors. We have discussed the mechanism of each chemical reaction with a focus on non-equilibrium reactions. We found most of the reactions are activation controlled above the critical point and that the rate constants are not significantly pressure dependent below 300 °C. This work will aid industry with developing chemical control strategies to suppress the concentration of eroding species.
Collapse
Affiliation(s)
- Guangdong Liu
- Department of Physics, Mount Allison University, Sackville, NB E4L 1E2, Canada
| | - Cody Landry
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB E4L 1E2, Canada
| | - Khashayar Ghandi
- Department of Physics, Mount Allison University, Sackville, NB E4L 1E2, Canada
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB E4L 1E2, Canada
| |
Collapse
|