Abstract
Nanoscale resolved quantifications of almandine's (Fe3Al2(SiO4)3) dissolution rates across a range of pH's (1 ≤ pH ≤ 13) - established using vertical scanning interferometry (VSI) - reveal that its dissolution rate achieves a minimum around pH 5. This minimum coincides with almandine's point of zero charge (PZC). These trends in almandine's dissolution can be estimated using the Butler-Volmer (BV) equation that reveals linkages between surface potentials and dissolution rates, demonstrating proton- and hydroxyl-promoted breakage of Si-O bonds. In contrast with well-polymerized silicates, the dissolution of almandine can also occur through the rupture of its cationic bonds. This behavior is reflected in the observed influences of irradiation on its dissolution kinetics. Molecular dynamics simulations highlight that irradiation induces alterations in the atomic structure of almandine by reducing the coordination state of the cations (Fe2+ and Al3+); thereby enhancing its reactivity by a factor of two. This is consistent with the minor change induced in the structure of almandine's silicate backbone, whose surface charge densities produce the observed pH dependence (and rate control) of dissolution rates. These findings reveal the influential roles of surface potential arising from solution pH, and atomic scale alterations on affecting the reactivity of garnet-type silicates.
| Original language | English (US) |
|---|---|
| Journal | Journal of Physical Chemistry C |
| DOIs | |
| State | Accepted/In press - May 11 2018 |
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ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Energy(all)
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
Cite this
Role of Electrochemical Surface Potential and Irradiation on Garnet-type Almandine's Dissolution Kinetics. / Hsiao, Yi Hsuan; La Plante, Erika Callagon; Krishnan, N. M.Anoop; Dobbs, Howard A.; Le Pape, Yann; Neithalath, Narayanan; Bauchy, Mathieu; Israelachvili, Jacob N.; Sant, Gaurav N.
In: Journal of Physical Chemistry C, 11.05.2018.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Role of Electrochemical Surface Potential and Irradiation on Garnet-type Almandine's Dissolution Kinetics
AU - Hsiao, Yi Hsuan
AU - La Plante, Erika Callagon
AU - Krishnan, N. M.Anoop
AU - Dobbs, Howard A.
AU - Le Pape, Yann
AU - Neithalath, Narayanan
AU - Bauchy, Mathieu
AU - Israelachvili, Jacob N.
AU - Sant, Gaurav N.
PY - 2018/5/11
Y1 - 2018/5/11
N2 - Nanoscale resolved quantifications of almandine's (Fe3Al2(SiO4)3) dissolution rates across a range of pH's (1 ≤ pH ≤ 13) - established using vertical scanning interferometry (VSI) - reveal that its dissolution rate achieves a minimum around pH 5. This minimum coincides with almandine's point of zero charge (PZC). These trends in almandine's dissolution can be estimated using the Butler-Volmer (BV) equation that reveals linkages between surface potentials and dissolution rates, demonstrating proton- and hydroxyl-promoted breakage of Si-O bonds. In contrast with well-polymerized silicates, the dissolution of almandine can also occur through the rupture of its cationic bonds. This behavior is reflected in the observed influences of irradiation on its dissolution kinetics. Molecular dynamics simulations highlight that irradiation induces alterations in the atomic structure of almandine by reducing the coordination state of the cations (Fe2+ and Al3+); thereby enhancing its reactivity by a factor of two. This is consistent with the minor change induced in the structure of almandine's silicate backbone, whose surface charge densities produce the observed pH dependence (and rate control) of dissolution rates. These findings reveal the influential roles of surface potential arising from solution pH, and atomic scale alterations on affecting the reactivity of garnet-type silicates.
AB - Nanoscale resolved quantifications of almandine's (Fe3Al2(SiO4)3) dissolution rates across a range of pH's (1 ≤ pH ≤ 13) - established using vertical scanning interferometry (VSI) - reveal that its dissolution rate achieves a minimum around pH 5. This minimum coincides with almandine's point of zero charge (PZC). These trends in almandine's dissolution can be estimated using the Butler-Volmer (BV) equation that reveals linkages between surface potentials and dissolution rates, demonstrating proton- and hydroxyl-promoted breakage of Si-O bonds. In contrast with well-polymerized silicates, the dissolution of almandine can also occur through the rupture of its cationic bonds. This behavior is reflected in the observed influences of irradiation on its dissolution kinetics. Molecular dynamics simulations highlight that irradiation induces alterations in the atomic structure of almandine by reducing the coordination state of the cations (Fe2+ and Al3+); thereby enhancing its reactivity by a factor of two. This is consistent with the minor change induced in the structure of almandine's silicate backbone, whose surface charge densities produce the observed pH dependence (and rate control) of dissolution rates. These findings reveal the influential roles of surface potential arising from solution pH, and atomic scale alterations on affecting the reactivity of garnet-type silicates.
UR - http://www.scopus.com/inward/record.url?scp=85049664328&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85049664328&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.8b04459
DO - 10.1021/acs.jpcc.8b04459
M3 - Article
AN - SCOPUS:85049664328
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
ER -