EXAFS study of Zn sorption mechanisms on hydrous ferric oxide over extended reaction time

• Published in: Journal of colloid and interface science Vol. 286; no. 1; pp. 82 - 89
• Main Authors: Lee, Shinwoo, Anderson, Paul R.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.06.2005; Elsevier
• Subjects: Adsorption; Chemistry; Exact sciences and technology; EXAFS; Ferric Compounds - chemistry; General and physical chemistry; HFO; Sorption; Spectrum Analysis - methods; Surface physical chemistry; Time Factors; Water - chemistry; X-Rays; Zinc - chemistry; Sorption; HFO; Zn; EXAFS; Adsorption; Reaction time; Oxides; Mechanism; EXAFS spectrometry
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2005.01.005

The sorption species and coordination environment of zinc sorbed on to hydrous ferric oxide (HFO) did not change for aging times up to six months. At an initial concentration of 10 4 − M, Zn formed innersphere surface complexes on the surface of HFO. Zn was tetrahedrally coordinated with oxygen atoms at Zn O bond distance of ∼1.94–1.97 Å with coordination number of ∼3.8–4.7. In the second shell Zn appeared to be coordinated with Fe with a bond distance of ∼3.42–3.49 Å. At an initial concentration of 10 3 −   M , both innersphere and polynuclear complexes were feasible sorption products. The first shell was tetrahedrally coordinated with about four oxygen atoms at a bond distance of 1.96 Å. The second shell could be attributed to either Zn Fe or Zn Zn correlations with almost the same bond distance of 3.42–3.44 Å.