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XAFS study of Cu(II) at the water-goethite (alpha-FeOOH) interface

Bochatay, L.; Persson, Per LU ; Lovgren, L. and Brown, G. E. (1997) In Journal de Physique IV: Proceedings 7. p.819-820
Abstract
Cu(II) complexation at the water-goethite (alpha-FeOOH) interface was studied by XAFS, potentiometry, and sorption experiments. Thermodynamic data indicate that the initial Cu(II) sorption is not accompanied by release of a H+. As pH is raised, hydrolysis occurs, and a maximum of two H+ are released per sorbed ion. Sorption experiments also show that Cu(II) complexation is insensitive to variation in ionic strength, indicating inner-sphere Cu complexes. The Cu K-edge XAFS suggest that the Cu(II) surface complexes are Jahn-Teller distorted with an equatorial plane of oxygens at approximately 1.95 Angstrom. At pH 5, no 2nd coordination shell is observed. However, at pH 8 there is a well-defined 2nd shell which is best modeled with two Cu... (More)
Cu(II) complexation at the water-goethite (alpha-FeOOH) interface was studied by XAFS, potentiometry, and sorption experiments. Thermodynamic data indicate that the initial Cu(II) sorption is not accompanied by release of a H+. As pH is raised, hydrolysis occurs, and a maximum of two H+ are released per sorbed ion. Sorption experiments also show that Cu(II) complexation is insensitive to variation in ionic strength, indicating inner-sphere Cu complexes. The Cu K-edge XAFS suggest that the Cu(II) surface complexes are Jahn-Teller distorted with an equatorial plane of oxygens at approximately 1.95 Angstrom. At pH 5, no 2nd coordination shell is observed. However, at pH 8 there is a well-defined 2nd shell which is best modeled with two Cu atoms at 2.96 Angstrom. The appearance of a 2nd coordination shell at higher pH is attributed to the formation of hydroxo-bridged Cu(II) surface polymers. (Less)
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author
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal de Physique IV: Proceedings
volume
7
pages
819 - 820
publisher
EDP Sciences
ISSN
1764-7177
DOI
10.1051/jp4:1997246
language
English
LU publication?
no
id
a68f4934-ac70-4910-aa5c-88a6e7b47268 (old id 4332664)
date added to LUP
2014-03-04 09:44:29
date last changed
2016-11-24 13:33:49
@article{a68f4934-ac70-4910-aa5c-88a6e7b47268,
  abstract     = {Cu(II) complexation at the water-goethite (alpha-FeOOH) interface was studied by XAFS, potentiometry, and sorption experiments. Thermodynamic data indicate that the initial Cu(II) sorption is not accompanied by release of a H+. As pH is raised, hydrolysis occurs, and a maximum of two H+ are released per sorbed ion. Sorption experiments also show that Cu(II) complexation is insensitive to variation in ionic strength, indicating inner-sphere Cu complexes. The Cu K-edge XAFS suggest that the Cu(II) surface complexes are Jahn-Teller distorted with an equatorial plane of oxygens at approximately 1.95 Angstrom. At pH 5, no 2nd coordination shell is observed. However, at pH 8 there is a well-defined 2nd shell which is best modeled with two Cu atoms at 2.96 Angstrom. The appearance of a 2nd coordination shell at higher pH is attributed to the formation of hydroxo-bridged Cu(II) surface polymers.},
  author       = {Bochatay, L. and Persson, Per and Lovgren, L. and Brown, G. E.},
  issn         = {1764-7177},
  language     = {eng},
  pages        = {819--820},
  publisher    = {EDP Sciences},
  series       = {Journal de Physique IV: Proceedings},
  title        = {XAFS study of Cu(II) at the water-goethite (alpha-FeOOH) interface},
  url          = {http://dx.doi.org/10.1051/jp4:1997246},
  volume       = {7},
  year         = {1997},
}