Molecular-scale controls on heteroepitaxy at mineral-water interfaces
EMSL Project ID
48389
Abstract
The objective of the proposed research is to elucidate and quantify the molecular-scale mechanisms of heteroepitaxial nucleation and growth at mineral-water interfaces. Despite several examples of heteroepitaxy occurring in nature or in simulated natural conditions, our understanding of heteroepitaxial nucleation and growth at mineral-water interfaces in conditions relevant to natural systems is limited. The limitations of our current knowledge are due to the difficulties in detecting and probing mineral coatings with nanometer-scale dimensions and structures similar to those of their substrates. Importantly, an understanding of heteroepitaxy at mineral-water interfaces is critical to radically improve current predictive models since this phenomenon leads to non-equilibrium conditions and/or equilibrium conditions that differ from bulk behavior. These conditions include undersaturation with respect to the substrate due to armoring by surface coatings, the partitioning of foreign ions in mineral surfaces, and the formation of epitaxial solid solutions with compositions that differ from those expected based on bulk thermodynamic considerations. These effects ultimately need to be incorporated in macroscopic predictive models of the long-term behavior of natural systems for their applications to the fate, transport, and remediation of contaminants in surface and subsurface environments and to carbon sequestration in geologic repositories.A range of unique experimental probes available in EMSL will be deployed to overcome current limitations and systematically isolate and quantify the key factors affecting heteroepitaxy at mineral-water interfaces. The formation of metal carbonate phases on the (10.4) calcite surface will be used as a model system. The metal carbonate series provides an ideal system for quantifying the effects of key hypothesized factors, such as lattice misfit, saturation state, and the presence of foreign ions. Atomic force microscopy will be used to probe the time dependence of the size and morphology of nucleation and growth features; high-resolution transmission electron microscopy will be employed to gain insight into the atomic-scale structure of the epitaxial coatings; and x-ray photoelectron spectroscopy, electron energy loss spectroscopy, and atom probe tomography will be used to determine the composition of the epitaxial coatings. In addition, an atomistic model of heteroepitaxial carbonate films will be constructed to help interpret experimental observations and guide experimental designs.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2014-10-01
End Date
2016-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Team Members
Related Publications
Ilton ES, JE Post, PJ Heaney, FT Ling, and SN Kerisit. 2016. "XPS Determination of Mn Oxidation States in Mn (Hydr)oxides." Applied Surface Science 366:475-485. doi:10.1016/j.apsusc.2015.12.159
Kerisit S N,Bylaska E J,Massey S,McBriarty M E,Ilton E S 2016. "Ab Initio Molecular Dynamics Simulations of Uranium Incorporated in Goethite with Implications for Interpreting X-Ray Absorption Spectroscopy of Trace Polyvalent Metals Associated with Major Host Minerals" Journal of the American Chemical Society 55(22):11736–11746. 10.1021/acs.inorgchem.6b01773
McBriarty ME, JA Soltis, SN Kerisit, O Qafoku, ME Bowden, EJ Bylaska, JJ De Yoreo, and ES Ilton. 2017. "Trace Uranium Partitioning in a Multi-Phase Nano-FeOOH System." Environmental Science & Technology 51(9):4970-4977. doi:10.1021/acs.est.7b00432
Riechers S.L., K.M. Rosso, and S.N. Kerisit. 2017. "Nucleation and Epitaxy-Mediated Phase Transformation of a Precursor Cadmium Carbonate Phase at the Calcite/Water Interface." Journal of Physical Chemistry C 121, no. 9:5012-5019. PNNL-SA-122339. doi:10.1021/acs.jpcc.6b11727
Xu M, ES Ilton, MH Engelhard, O Qafoku, AR Felmy, KM Rosso, and SN Kerisit. 2015. "Heterogeneous growth of cadmium and cobalt carbonate phases at the (10-14) calcite surface." Chemical Geology 397:24-36. doi:DOI:10.1016/j.chemgeo.2015.01.003
Xu M, SL Riechers, ES Ilton, Y Du, L Kovarik, T Varga, BW Arey, O Qafoku, and SN Kerisit. 2017. "Manganese-Calcium Intermixing Facilitates Heteroepitaxial Growth at the (10-14) Calcite-Water Interface." Chemical Geology 470:152-163. doi:10.1016/j.chemgeo.2017.09.001