One-Dimensional Confinement Inhibits Water Dissociation in Carbon Nanotubes
The effect of nanoconfinement on the self-dissociation of water constitutes an open problem whose elucidation poses a serious challenge to experiments and simulations alike. In slit pores of width ?1 nm, recent first-principles calculations have predicted that the dissociation constant of H2O increa...
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2018
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19487185_v9_n17_p5029_Sirkin http://hdl.handle.net/20.500.12110/paper_19487185_v9_n17_p5029_Sirkin |
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paper:paper_19487185_v9_n17_p5029_Sirkin2023-06-08T16:32:35Z One-Dimensional Confinement Inhibits Water Dissociation in Carbon Nanotubes Calculations Carbon nanotubes Equilibrium constants Free energy Molecular dynamics Pore size Yarn Biased sampling Characteristic length Dissociation constant First-principles calculation Hydronium ions Nanoconfinements Orders of magnitude Water dissociation Dissociation The effect of nanoconfinement on the self-dissociation of water constitutes an open problem whose elucidation poses a serious challenge to experiments and simulations alike. In slit pores of width ?1 nm, recent first-principles calculations have predicted that the dissociation constant of H2O increases by almost 2 orders of magnitude [ Muñoz-Santiburcio and Marx, Phys. Rev. Lett. 2017, 119, 056002 ]. In the present study, quantum mechanics?molecular mechanics simulations are employed to compute the dissociation free-energy profile of water in a (6,6) carbon nanotube. According to our results, the equilibrium constant Kw drops by 3 orders of magnitude with respect to the bulk phase value, at variance with the trend predicted for confinement in two dimensions. The higher barrier to dissociation can be ascribed to the undercoordination of the hydroxide and hydronium ions in the nanotube and underscores that chemical reactivity does not exhibit a monotonic behavior with respect to pore size but may vary substantially with the characteristic length scale and dimensionality of the confining media. © 2018 American Chemical Society. 2018 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19487185_v9_n17_p5029_Sirkin http://hdl.handle.net/20.500.12110/paper_19487185_v9_n17_p5029_Sirkin |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Calculations Carbon nanotubes Equilibrium constants Free energy Molecular dynamics Pore size Yarn Biased sampling Characteristic length Dissociation constant First-principles calculation Hydronium ions Nanoconfinements Orders of magnitude Water dissociation Dissociation |
| spellingShingle |
Calculations Carbon nanotubes Equilibrium constants Free energy Molecular dynamics Pore size Yarn Biased sampling Characteristic length Dissociation constant First-principles calculation Hydronium ions Nanoconfinements Orders of magnitude Water dissociation Dissociation One-Dimensional Confinement Inhibits Water Dissociation in Carbon Nanotubes |
| topic_facet |
Calculations Carbon nanotubes Equilibrium constants Free energy Molecular dynamics Pore size Yarn Biased sampling Characteristic length Dissociation constant First-principles calculation Hydronium ions Nanoconfinements Orders of magnitude Water dissociation Dissociation |
| description |
The effect of nanoconfinement on the self-dissociation of water constitutes an open problem whose elucidation poses a serious challenge to experiments and simulations alike. In slit pores of width ?1 nm, recent first-principles calculations have predicted that the dissociation constant of H2O increases by almost 2 orders of magnitude [ Muñoz-Santiburcio and Marx, Phys. Rev. Lett. 2017, 119, 056002 ]. In the present study, quantum mechanics?molecular mechanics simulations are employed to compute the dissociation free-energy profile of water in a (6,6) carbon nanotube. According to our results, the equilibrium constant Kw drops by 3 orders of magnitude with respect to the bulk phase value, at variance with the trend predicted for confinement in two dimensions. The higher barrier to dissociation can be ascribed to the undercoordination of the hydroxide and hydronium ions in the nanotube and underscores that chemical reactivity does not exhibit a monotonic behavior with respect to pore size but may vary substantially with the characteristic length scale and dimensionality of the confining media. © 2018 American Chemical Society. |
| title |
One-Dimensional Confinement Inhibits Water Dissociation in Carbon Nanotubes |
| title_short |
One-Dimensional Confinement Inhibits Water Dissociation in Carbon Nanotubes |
| title_full |
One-Dimensional Confinement Inhibits Water Dissociation in Carbon Nanotubes |
| title_fullStr |
One-Dimensional Confinement Inhibits Water Dissociation in Carbon Nanotubes |
| title_full_unstemmed |
One-Dimensional Confinement Inhibits Water Dissociation in Carbon Nanotubes |
| title_sort |
one-dimensional confinement inhibits water dissociation in carbon nanotubes |
| publishDate |
2018 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19487185_v9_n17_p5029_Sirkin http://hdl.handle.net/20.500.12110/paper_19487185_v9_n17_p5029_Sirkin |
| _version_ |
1768544842195927040 |