Analysis of the uranium chemical state by XPS: is what you see real?
Analysis of the uranium chemical state by XPS: is what you see real?
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DOI：
10.1016/j.apsusc.2021.151886
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发表时间：
2021-11
影响因子：
6.7
通讯作者：
Shirong Qiang;Jingjing Wang;Yun Wang;Long-miao Yuan;Leiping Shi;Zhe Ding;Wei Wang;Jianjun Liang-Jianj
中科院分区：
文献类型：
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作者：
Shirong Qiang;Jingjing Wang;Yun Wang;Long-miao Yuan;Leiping Shi;Zhe Ding;Wei Wang;Jianjun Liang-Jianj
X-ray photoelectron spectroscopy (XPS) is an efficient technique for recognizing the state of elements. However, the effects of X-ray irradiation on change in the chemical state are sometimes ignored, which may impair the understanding of the environmental behavior of these elements. This study determined the change in the U 4f spectra induced by X-ray irradiation during XPS detection. For U(VI) on non-semiconductors, X-ray irradiation led to a negative shift of U 4f7/2to ∼ 380.8 eV due to the break of the uranyl molecules, but not resulting in U(IV) species. However, owing to the photocatalytic reduction of U(VI), the irradiation of U(VI) loaded semiconductors rapidly induced the negative shift of U 4f7/2peak to ∼ 379.8 eV, which is the characteristic of U(IV). Moreover, apparent photo-reduction occurred even if the samples were far from the center of the X-ray beam (>3971 μm). Based on these findings, methods for reducing potential error due to X-ray irradiation are suggested, including using the minimum scan time, measuring uranium-containing samples first or independent of other samples, and using X-ray of lower intensity. The results indicated that X-ray induced alteration to the chemical states must be considered when using X-ray techniques.
