Dissolution Kinetics of Epitaxial Cadmium Carbonate Overgrowths on Dolomite
Abstract
Thin films grown on mineral surfaces can immobilize toxic metals in natural systems, but the effects of epitaxy and film thickness on dissolution rates of the overgrowth are typically unknown. To explore these effects, otavite (CdCO3) films were grown on dolomite (104) surfaces from aqueous solutions containing [Cd] = [Ca] = [CO3] = 0.2 mM for 1–48 h and then dissolved in deionized water. Films of various thicknesses and strain states were obtained by varying the growth reaction time. Growth for up to 3 h produced strained thin films with Cd coverages of <4.3 ± 0.6 equivalent monolayers (ML) (corresponding to a thickness of up to 17 Å), whereas reaction times of up to 48 h produced thicker films with as many as 114 ± 14 equivalent ML of Cd. Intrinsic dissolution rates were measured as a function of otavite film thickness by a combination of synchrotron X-ray fluorescence, specular X-ray reflectivity, and atomic force microscopy. As a result, the initial dissolution rates for unstrained films were comparable to those reported for synthetic otavite powders, whereas the thinnest films (<3.1 ± 1.1 ML) dissolved at a 50% slower rate, indicating that epitaxial strain effectively enhanced their stability. We discuss potentialmore »
- Authors:
-
- Univ. of Illinois at Chicago, Chicago, IL (United States); Univ. of California, Los Angeles, CA (United States)
- Argonne National Lab. (ANL), Lemont, IL (United States)
- Univ. of Chicago, Chicago, IL (United States)
- Univ. of Delaware, Newark, DE (United States)
- Univ. of Illinois at Chicago, Chicago, IL (United States)
- Publication Date:
- Research Org.:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- OSTI Identifier:
- 1496224
- Grant/Contract Number:
- AC02-06CH11357
- Resource Type:
- Journal Article: Accepted Manuscript
- Journal Name:
- ACS Earth and Space Chemistry
- Additional Journal Information:
- Journal Volume: 3; Journal Issue: 2; Journal ID: ISSN 2472-3452
- Publisher:
- American Chemical Society
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; x-ray reflectivity; carbonate; dissolution; epitaxial; film; stability
Citation Formats
La Plante, Erika Callagon, Lee, Sang Soo, Eng, Peter J., Stubbs, Joanne E., Fenter, Paul, Sturchio, Neil C., and Nagy, Kathryn L. Dissolution Kinetics of Epitaxial Cadmium Carbonate Overgrowths on Dolomite. United States: N. p., 2018.
Web. doi:10.1021/acsearthspacechem.8b00115.
La Plante, Erika Callagon, Lee, Sang Soo, Eng, Peter J., Stubbs, Joanne E., Fenter, Paul, Sturchio, Neil C., & Nagy, Kathryn L. Dissolution Kinetics of Epitaxial Cadmium Carbonate Overgrowths on Dolomite. United States. https://doi.org/10.1021/acsearthspacechem.8b00115
La Plante, Erika Callagon, Lee, Sang Soo, Eng, Peter J., Stubbs, Joanne E., Fenter, Paul, Sturchio, Neil C., and Nagy, Kathryn L. 2018.
"Dissolution Kinetics of Epitaxial Cadmium Carbonate Overgrowths on Dolomite". United States. https://doi.org/10.1021/acsearthspacechem.8b00115. https://www.osti.gov/servlets/purl/1496224.
@article{osti_1496224,
title = {Dissolution Kinetics of Epitaxial Cadmium Carbonate Overgrowths on Dolomite},
author = {La Plante, Erika Callagon and Lee, Sang Soo and Eng, Peter J. and Stubbs, Joanne E. and Fenter, Paul and Sturchio, Neil C. and Nagy, Kathryn L.},
abstractNote = {Thin films grown on mineral surfaces can immobilize toxic metals in natural systems, but the effects of epitaxy and film thickness on dissolution rates of the overgrowth are typically unknown. To explore these effects, otavite (CdCO3) films were grown on dolomite (104) surfaces from aqueous solutions containing [Cd] = [Ca] = [CO3] = 0.2 mM for 1–48 h and then dissolved in deionized water. Films of various thicknesses and strain states were obtained by varying the growth reaction time. Growth for up to 3 h produced strained thin films with Cd coverages of <4.3 ± 0.6 equivalent monolayers (ML) (corresponding to a thickness of up to 17 Å), whereas reaction times of up to 48 h produced thicker films with as many as 114 ± 14 equivalent ML of Cd. Intrinsic dissolution rates were measured as a function of otavite film thickness by a combination of synchrotron X-ray fluorescence, specular X-ray reflectivity, and atomic force microscopy. As a result, the initial dissolution rates for unstrained films were comparable to those reported for synthetic otavite powders, whereas the thinnest films (<3.1 ± 1.1 ML) dissolved at a 50% slower rate, indicating that epitaxial strain effectively enhanced their stability. We discuss potential reasons for this difference.},
doi = {10.1021/acsearthspacechem.8b00115},
url = {https://www.osti.gov/biblio/1496224},
journal = {ACS Earth and Space Chemistry},
issn = {2472-3452},
number = 2,
volume = 3,
place = {United States},
year = {Thu Dec 20 00:00:00 EST 2018},
month = {Thu Dec 20 00:00:00 EST 2018}
}
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