Surface complexation of Hg2+ on goethite: Mechanism from EXAFS spectroscopy and density functional calculations

CR Collins*, DM Sherman, KV Ragnarsdottir

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)

61 Citations (Scopus)

Abstract

EXAFS spectra of Hg2+ sorbed on goethite at pH 4.60 has revealed the existence of an inner-sphere complex with an immediate coordination shell of 2 O atoms at 2.04 Angstrom and a further shell of 1 Fe atom at 3.28 Angstrom. Using density functional calculations, we determined the optimized geometries of small clusters representing surface complexes. These results shows that adsorption of Hg2+ occurs via two oxygen atoms bound to edge-sharing Fe sites on the (110) surface. This is the same surface site we find for Cd (1, 2) and Sr (3). The short Hg-O bond length shows that the oxygens bridging Hg and Fe atoms are deprotonated. (C) 1999 Academic Press.

Original languageEnglish
Pages (from-to)345-350
Number of pages6
JournalJournal of Colloid and Interface Science
Volume219
Issue number2
Publication statusPublished - 15 Nov 1999

Keywords

  • mercury
  • goethite
  • adsorption
  • EXAFS
  • density functional calculations
  • ADSORPTION
  • MERCURY
  • ENVIRONMENT
  • OXIDES

Cite this