Termination and Water Adsorption at
the
a-Al2O3 (012)-Aqueous
Solution Interface
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The derived
interfacial structure of the a-Al2O3
(012)-water interface. The derived electron density is shown at
bottom and a schematic structure is shown at top, with the top of
the outermost Al2O3 layer near z = 0 Ĺ.
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The interaction of water with mineral surfaces is important to many diverse
fields (e.g., geochemistry, heterogeneous catalysis, crystal growth, corrosion,
atmospheric chemistry) and knowledge of the structure of interfacial water is
needed to obtain a fundamental understanding of the key processes and mechanisms
that may be occurring in more complex environmental systems.
- Catalano et al. determined the structure of the Al2O3(012)-water
interface. The results differ from that previously reported for this surface
exposed to water in high-vacuum conditions, demonstrating the necessity of
true in-situ measurements for understanding the interaction of mineral
surfaces with aqueous solutions.
- The results were determined using a model-independent approach, using an
error correction algorithm previously developed for the analysis of specular
reflectivity data by Fenter and Zhang.
- The termination consists of a full Al2O3 layer
plus an additional oxygen layer that completes the coordination shell of the
upper aluminum site, as well as two sites of adsorbed water above the
mineral surface.
Reference
J. G. Catalano, C. Park, Z. Zhang, and P. Fenter, “Termination and Water
Adsorption at the
a-Al2O3
(012)-Aqueous Solution Interface,” Langmuir, 22 4668-4673 (2006). |
