X-ray photoelectron spectroscopic studies of sulfates and bisulfates interpreted by X? and band structure calculations
2000; Wiley; Volume: 29; Issue: 4 Linguagem: Inglês
10.1002/(sici)1096-9918(200004)29
ISSN1096-9918
AutoresAhmad Ali Audi, Peter M. A. Sherwood,
Tópico(s)Iron oxide chemistry and applications
ResumoValence-band and core-level x-ray photoelectron spectroscopy (XPS) studies of sulfate and bisulfate ions are reported. Sulfate and bisulfate ions cannot be distinguished in their core XPS spectra. The valence band region shows a significant difference in the relative intensity and separation of two prominent peaks, and this difference can be used to distinguish between sulfate and bisulfate because the separation is larger in the case of sulfate (∼4 eV) than for bisulfates (∼3 eV). We show that this difference can be used in a wide range of sulfate and bisulfates, including main group and transition metal compounds: Li2SO4, Na2SO4, K2SO4, MgSO4, Al2(SO4)3, Fe2(SO4)3, FeSO4, Ni2SO4, Ag2SO4, (NH4)2SO4, NaHSO4, KHSO4 and NH4HSO4 (some of these are hydrated). The sulfate and bisulfate spectra can be interpreted by cluster (multiple scattered-wave Xα calculations) and band structure calculations. A careful analysis of the valence band spectra of Li2SO4H2O interpreted by band structure calculation results shows that the water of crystallization can be identified in the valence band region. Copyright © 2000 John Wiley & Sons, Ltd.
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