Sorption of Eu on dickite particles studied by Raman, luminescence, and X-ray photoelectron spectroscopies

• Published in: Comptes rendus. Chimie Vol. 10; no. 10-11; pp. 1050 - 1059
• Main Authors: Cremel, Sebastien, Zamama, Otmane, Dossot, Manuel, Lambert, Jacques, Humbert, Bernard, Ehrhardt, Jean-Jacques
• Format: Journal Article
• Language: English; French
• Published: 01.10.2007
• ISSN: 1631-0748
• DOI: 10.1016/j.crci.2007.01.013

The sorption of europium(III) species from EuCl3 solution at pH=5.4 onto dickite particles is investigated using spectroscopic methods. Thanks to the neutrality of phyllosilicate sheets of dickite, cation exchange is prevented. X-ray photoelectron spectroscopy reveals that chloride atoms probably remain in the ligand sphere of the europium(III) cation. The edge site-specific reactivity is evidenced by epifluorescence microscopy and Raman spectroscopy. Comparison between dickite/europium(III) samples rinsed or not with distilled water shows that the surface processes not only involve inner-sphere complex formation, but also either outer-sphere complex or surface precipitation. Raman spectra also indicate that europium(III) surface complexes are preferentially localised at the edge of tetrahedral silica sheets.