Journal article
Pb(II) Adsorption on Isostructural Hydrated Alumina and Hematite (0001) Surfaces: A DFT Study
Journal of physical chemistry. C, Vol.113(6), pp.2159-2170
02/12/2009
DOI: 10.1021/jp807321e
Abstract
The persistence of lead (Pb) in contaminated topsoil is ranked as one of the most serious environmental issues in the U.S. and other countries. Adsorption of Pb at the aqueous interface of nanoscale metal oxide and metal (oxy)hydroxide particles is perhaps the most significant process responsible for controlling contaminant sequestration and mobility, but the process is poorly understood at the molecular level. Experimental studies of absorption of Pb onto bulk minerals have indicated significant differences in reactivity, but the molecular basis for these differences has remained elusive due to the challenges of observing and modeling the complex chemistry that exists at the water−oxide interface. In this work, we present a detailed ab initio theoretical investigation aimed at understanding the fundamental physical and chemical characteristics of Pb adsorption onto the (0001) surface of two common minerals, α-Al2O3 and α-Fe2O3. The results of our periodic density functional theory (DFT) calculations show that the adsorption energy of Pb(II) on hematite is more than four times the value on isostructural alumina with the same fully hydroxylated surface stoichiometry due to bonding interactions enabled by the partially occupied Fe d-band. Site preference for Pb(II) adsorption on alumina is shown to depend strongly on the cost to disrupt highly stable hydrogen bonding networks on the hydrated surface, but is less of a factor for the stronger Pb-hematite interaction.
Details
- Title: Subtitle
- Pb(II) Adsorption on Isostructural Hydrated Alumina and Hematite (0001) Surfaces: A DFT Study
- Creators
- Sara E Mason - Physics Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, and Department of Chemistry and Biochemistry University of Alaska, Fairbanks, P.O. Box 756160, Fairbanks, Alaska 99775Christopher R Iceman - Physics Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, and Department of Chemistry and Biochemistry University of Alaska, Fairbanks, P.O. Box 756160, Fairbanks, Alaska 99775Kunaljeet S Tanwar - Physics Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, and Department of Chemistry and Biochemistry University of Alaska, Fairbanks, P.O. Box 756160, Fairbanks, Alaska 99775Thomas P Trainor - Physics Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, and Department of Chemistry and Biochemistry University of Alaska, Fairbanks, P.O. Box 756160, Fairbanks, Alaska 99775Anne M Chaka - Physics Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, and Department of Chemistry and Biochemistry University of Alaska, Fairbanks, P.O. Box 756160, Fairbanks, Alaska 99775
- Resource Type
- Journal article
- Publication Details
- Journal of physical chemistry. C, Vol.113(6), pp.2159-2170
- DOI
- 10.1021/jp807321e
- NLM abbreviation
- J Phys Chem C Nanomater Interfaces
- ISSN
- 1932-7447
- eISSN
- 1932-7455
- Publisher
- American Chemical Society
- Language
- English
- Date published
- 02/12/2009
- Academic Unit
- Chemistry
- Record Identifier
- 9984216685802771
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