XPS studies on the electronic structure of bonding between solid and solutes: Adsorption of arsenate, chromate, phosphate, Pb{sup 2+}, and Zn{sup 2+} ions on amorphous black ferric oxyhydroxide
The adsorption of three anions (AsO{sub 4}{sup 3{minus}}, PO{sub 4}{sup 3{minus}}, and CrO{sub 4}{sup 2{minus}}) and two cations (Zn{sup 2+} and Pb{sup 2+}) has been determined on a new form of amorphous black ferric oxyhydroxide that resembles in local structure {beta}-FeOOH, akaganeite. The nature of the interaction between FeOOH substrate and the above mentioned adsorbates is characterized with X-ray photoelectron spectroscopy on the core and valence band levels of trivalent iron and oxygen using frontier molecular orbital theory as theoretical framework. Findings indicate that substantial and variable charge transfer occurs in which the FeOOH substrate can function either as a Lewis acid or base in its interaction with different adsorbates. Findings suggest that the valence band spectra can be used to estimate qualitatively the energy level separation between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the surface complexes and to assess the chemical affinity between substrate and adsorbate.
- Research Organization:
- Utrecht Univ. (NL)
- OSTI ID:
- 20020885
- Journal Information:
- Geochimica et Cosmochimica Acta, Vol. 64, Issue 7; Other Information: PBD: Apr 2000; ISSN 0016-7037
- Country of Publication:
- United States
- Language:
- English
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