Water orientation and hydrogen-bond structure at the fluorite/water interface

Abstract

AbstractWater in contact with mineral interfaces is important for a variety of different processes. Here, we present a combined theoretical/experimental study which provides a quantitative, molecular-level understanding of the ubiquitous and important CaF2/water interface. Our results show that, at low pH, the surface is positively charged, causing a substantial degree of water ordering. The surface charge originates primarily from the dissolution of fluoride ions, rather than from adsorption of protons to the surface. At high pH we observe the presence of Ca-OH species pointing into the water. These OH groups interact remarkably weakly with the surrounding water and are responsible for the “free OH” signature in the VSFG spectrum, which can be explained from local electronic structure effects. The quantification of the surface termination, near-surface ion distribution and water arrangement is enabled by a combination of advanced phase-resolved Vibrational Sum Frequency Generation spectra of CaF2/water interfaces and state-of-the-art ab initio molecular dynamics simulations which include electronic structure effects.

Autoren

Rémi Khatib
Ellen HG Backus
Mischa Bonn
María-José Perez-Haro
Marie-Pierre Gaigeot
Marialore Sulpizi

DOI

10.1038/srep24287

eISSN

2045-2322

Ausgabe der Veröffentlichung

1

Zeitschrift

Scientific Reports

Sprache

en

Artikelnummer

24287

Online publication date

2016

Status

Published online

Herausgeber

Springer Science and Business Media LLC

Herausgeber URL

http://dx.doi.org/10.1038/srep24287

Datum der Datenerfassung

2023

Titel

Water orientation and hydrogen-bond structure at the fluorite/water interface

Ausgabe der Zeitschrift

6

Data source: Crossref

Abstract

Water in contact with mineral interfaces is important for a variety of different processes. Here, we present a combined theoretical/experimental study which provides a quantitative, molecular-level understanding of the ubiquitous and important CaF2/water interface. Our results show that, at low pH, the surface is positively charged, causing a substantial degree of water ordering. The surface charge originates primarily from the dissolution of fluoride ions, rather than from adsorption of protons to the surface. At high pH we observe the presence of Ca-OH species pointing into the water. These OH groups interact remarkably weakly with the surrounding water, and are responsible for the "free OH" signature in the VSFG spectrum, which can be explained from local electronic structure effects. The quantification of the surface termination, near-surface ion distribution and water arrangement is enabled by a combination of advanced phase-resolved Vibrational Sum Frequency Generation spectra of CaF2/water interfaces and state-of-the-art ab initio molecular dynamics simulations which include electronic structure effects.

Addresses

Johannes Gutenberg University Mainz, Staudingerweg 7, 55099 Mainz, Germany.

Autoren

Rémi Khatib
Ellen HG Backus
Mischa Bonn
María-José Perez-Haro
Marie-Pierre Gaigeot
Marialore Sulpizi

DOI

10.1038/srep24287

eISSN

2045-2322

Externe Identifier

PubMed Identifier: 27068326
PubMed Central ID: PMC4828669

Funding acknowledgements

European Research Council: 336679
European Research Council: 334368

Open access

true

ISSN

2045-2322

Zeitschrift

Scientific reports

Sprache

eng

Medium

Electronic

Online publication date

2016

Open access status

Open Access

Paginierung

24287

Datum der Veröffentlichung

2016

Status

Published

Publisher licence

CC BY

Datum der Datenerfassung

2016

Titel

Water orientation and hydrogen-bond structure at the fluorite/water interface.

Sub types

Research Support, Non-U.S. Gov't
research-article
Journal Article

Ausgabe der Zeitschrift

6

Files

https://www.nature.com/articles/srep24287.pdf https://europepmc.org/articles/PMC4828669?pdf=render

Data source: Europe PubMed Central

Abstract

Water in contact with mineral interfaces is important for a variety of different processes. Here, we present a combined theoretical/experimental study which provides a quantitative, molecular-level understanding of the ubiquitous and important CaF2/water interface. Our results show that, at low pH, the surface is positively charged, causing a substantial degree of water ordering. The surface charge originates primarily from the dissolution of fluoride ions, rather than from adsorption of protons to the surface. At high pH we observe the presence of Ca-OH species pointing into the water. These OH groups interact remarkably weakly with the surrounding water, and are responsible for the "free OH" signature in the VSFG spectrum, which can be explained from local electronic structure effects. The quantification of the surface termination, near-surface ion distribution and water arrangement is enabled by a combination of advanced phase-resolved Vibrational Sum Frequency Generation spectra of CaF2/water interfaces and state-of-the-art ab initio molecular dynamics simulations which include electronic structure effects.

Date of acceptance

2016

Autoren

Rémi Khatib
Ellen HG Backus
Mischa Bonn
María-José Perez-Haro
Marie-Pierre Gaigeot
Marialore Sulpizi

Autoren-URL

https://www.ncbi.nlm.nih.gov/pubmed/27068326

DOI

10.1038/srep24287

eISSN

2045-2322

Externe Identifier

PubMed Central ID: PMC4828669

Zeitschrift

Sci Rep

Sprache

eng

Country

England

Paginierung

24287

PII

srep24287

Datum der Veröffentlichung

2016

Status

Published online

Datum, an dem der Datensatz öffentlich gemacht wurde

2016

Titel

Water orientation and hydrogen-bond structure at the fluorite/water interface.

Sub types

Journal Article
Research Support, Non-U.S. Gov't

Ausgabe der Zeitschrift

6

Data source: PubMed

Water orientation and hydrogen-bond structure at the fluorite/water interface

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