Spectroscopic Characterization of the Uranium Carbonate Andersonite Na2Ca[UO2(CO3)3]·6H2O
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- 作者：Samer Amayri ; Thuro Arnold ; Tobias Reich ; Harald Foerstendorf ; Gerhard Geipel ; Gert Bernhard ; and Andreas Massanek
- 刊名：Environmental Science & Technology
- 出版年：2004
- 出版时间：November 15, 2004
- 年：2004
- 卷：38
- 期：22
- 页码：6032 - 6036
- 全文大小：199K
- 年卷期：v.38,no.22(November 15, 2004)
- ISSN：1520-5851
文摘
The uranium carbonate andersonite Na2Ca[UO2(CO3)3]·6H2O was synthesized and identified with classical analyticaland spectroscopic methods. The classical methodsapplied were powder X-ray diffraction (XRD), nitric aciddigestion, and scanning electron microcopy combined withenergy-dispersive spectroscopy (SEM/EDS). To characterizeandersonite spectroscopically, time-resolved laser-induced fluorescence spectroscopy (TRLFS), X-ray photoelectron spectroscopy (XPS), and Fourier transforminfrared spectroscopy (FT-IR) were used. Natural andsynthetic andersonite samples were characterized withthe nondestructive TRLFS by six fluorescence emission bandsat 470.6, 486.1, 505.4, 526.7, 549.6, and 573.9 nm. Inaddition, andersonite was characterized by FT-IR measurements by the appearance of the asymmetric stretchingvibration of the uranyl cation [
3(UO22+)] at 902 cm-1 witha shoulder at 913 cm-1. XPS measurements verified thecomposition of the synthetic andersonite sample. Themeasured intensity ratios of the XPS lines agree with thestoichiometry of Na2Ca[UO2(CO3)3]·6H2O. The XPS featuresof the inner valence molecular orbitals are characteristic ofthe [UO2(CO3)3]4- structural moiety. These spectroscopicmethods can be used to identify in a fingerprinting proceduresecondary U(VI) phases in mixtures with other phases oras thin coatings on mineral and rock surfaces.
3(UO22+)] at 902 cm-1 witha shoulder at 913 cm-1. XPS measurements verified thecomposition of the synthetic andersonite sample. Themeasured intensity ratios of the XPS lines agree with thestoichiometry of Na2Ca[UO2(CO3)3]·6H2O. The XPS featuresof the inner valence molecular orbitals are characteristic ofthe [UO2(CO3)3]4- structural moiety. These spectroscopicmethods can be used to identify in a fingerprinting proceduresecondary U(VI) phases in mixtures with other phases oras thin coatings on mineral and rock surfaces.