Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-24T19:00:29.778Z Has data issue: false hasContentIssue false
  • English
  • Français

In situ AFM and XPS Investigation of U6+ Reduction by Fe2+ on Hematite and Pyrite

Published online by Cambridge University Press:  23 May 2012

Jingjie Niu ,
Udo Becker  and
Rodney Ewing
Jingjie Niu
Affiliation:
Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109-1005, U.S.A.
Udo Becker
Affiliation:
Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109-1005, U.S.A.
Rodney Ewing
Affiliation:
Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109-1005, U.S.A.
Get access

Abstract

Uranyl adsorption/reduction by Fe2+ on hematite and pyrite has been studied at neutral pH under anoxic and CO2-free conditions. XPS results confirm that more U3O8 precipitates on hematite than on pyrite reacted for 24 h in 160 μM uranyl nitrate and 160 μM Fe2+ solution at initial pH 7.3. These results are explained in terms of co-adsorption energy and U atom Mulliken charge transfer by quantum mechanical calculations. Moreover, in situ fluid tapping-mode AFM experiments on hematite indicate a deceleration of the U reduction rate within 24 h due to the passivation of the surface caused by the formation of orthorhombic U3O8 crystals. In addition, crystals observed using AFM show morphologies of orthorhombic schoepite appearing on hematite after 5 h.

Keywords

Uadsorptionscanning probe microscopy (SPM)
Type
Articles
Information
MRS Online Proceedings Library (OPL) , Volume 1444: Symposium S/Y – Actinides and Nuclear Energy Materials , 2012 , mrss12-1444-y10-15
Copyright
Copyright © Materials Research Society 2012

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Langmuir, D., Geochim. Cosmochim. Acta 45, 547 (1987).Google Scholar
2. Burns, P. C., Can. Mineral. 43, 1839 (2005).Google Scholar
3. Morrison, S. J., Tripathi, V. S. and Spangler, R. R., J. Contam. Hydrol. 17, 347 (1995).Google Scholar
4. Martine, C. D., Coughlin, J.U. and Hunter, D. B., Geochim. Cosmochim. Acta 66, 3533–3534 (2002).Google Scholar
5. Scott, T.B., Tort, R. O. and Allen, G. C., Geochim. Cosmochim. Acta 71, 5044–5046 (2007).Google Scholar
6. Wersin, P., Hochella, M. F. Jr., . Persson, P, Redden, R., Leckie, J. O. and Harris, D., Geochim. Cosmochim. Acta 58, 2829–2831(1994).Google Scholar
7. Descostes, M., Schlegel, M. L., Eglizaud, N., Descamps, F., Miserque, F. and Simoni, E., Geochim. Cosmochim. Acta 74, 1551–1562 (2010).Google Scholar
8. Charlet, L., Silvester, E. and Liger, E., Chem. Geol. 151, 81–88 (1998).Google Scholar
9. Chadwick, D., Chem. Phys. Lett. 21, 291–294 (1973).Google Scholar
10. Allen, G. C., Crofts, J. A., Curtis, M. T., Tucker, P. M., Chadwick, D. and Hampson, P. J., J. Chem. Soc. Dalton 12, 1296–1301(1974a).Google Scholar
11. Allen, G.C. and Holmes, N.R., Journal of Nuclear Materials 223, 231–237 (1995).Google Scholar
12. Schindler, M. and Putnis, A., The Canadian Mineralogist 42, 1667–1681 (2004).Google Scholar