Structure of Hydrated $\alpha$-Fe$_2$O$_3$ (0001) and (1$\bar{1}$02)

ORAL

Abstract

The structure and reactivity of $\alpha$-Fe$_2$O$_3$ depends on several factors, including the composition of the bulk material, crystallographic orientation, and local coordination of the surface atoms. As an example, the adsorption and dissociation of water on $\alpha$-Fe$_2$O$_3$ and other metal oxide surfaces is not well understood, since the oxide surface has largely been characterized under ultrahigh vacuum or clean conditions. However, interactions at the solid-liquid and solid-solid interface play major roles in environmental processes, including contaminant sequestration, mobility, and bioavailability. In this work, we present density functional theory results on the structure of clean and hydrated $\alpha$-Fe$_2$O$_3$ (0001) and (1$\bar{1}$02), and show the changes in surface structure upon heterolytic water dissociation and water physisorption.

*National Science Foundation BES-0404400

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Authors

  • Cynthia Lo

    • National Institute of Standards and Technology, Chemical Science and Technology Laboratory

  • Anne Chaka

    • National Institute of Standards and Technology, Chemical Science and Technology Laboratory
    • National Institute of Standards and Technology, Physical and Chemical Properties, Gaithersburg, MD 20889
    • National Institute of Standards and Technology, Physical and Chemical Properties Division, Computational Chemistry Group

  • Thomas Trainor

    • University of Alaska Fairbanks, Department of Chemistry and Biochemistry