Synthesis and characterization of a uranium oxide hydrate framework with Sr( ii ) ions: structural insights and mixed uranium valences

A mixed-valence uranium oxide hydrate framework with Sr 2+ ions (UOF-Sr2) was synthesized hydrothermally and characterized with multiple structural and spectroscopic techniques. Compound UOF-Sr2 crystallizes in the monoclinic space group C 2/ c , having a complicated three-dimensional structure with...

Full description

Saved in:
Bibliographic Details
Published in:New journal of chemistry 2022-01, Vol.46 (3), p.1371-1380
Main Authors: Lu, Kimbal T., Zhang, Yingjie, Wei, Tao, Ablott, Timothy A., Nguyen, Thanh Ha, Zheng, Rongkun
Format: Article
Language:English
Subjects:
Chemical synthesis
Coordination
Crystal structure
Crystals
Raman spectroscopy
Single crystals
Spectrum analysis
Spent nuclear fuels
Synchrotrons
Uranium
Uranium oxides
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A mixed-valence uranium oxide hydrate framework with Sr 2+ ions (UOF-Sr2) was synthesized hydrothermally and characterized with multiple structural and spectroscopic techniques. Compound UOF-Sr2 crystallizes in the monoclinic space group C 2/ c , having a complicated three-dimensional structure with Sr 2+ ions in the narrow channels. Both SEM and TEM characterization revealed a thin-plate crystal morphology, with the TEM-SAED pattern indexed to the crystal structure determined by synchrotron single-crystal XRD. Bond valence sum analysis indicated the possible presence of pentavalent uranium in octahedral coordination environments, subsequently confirmed with diffuse reflectance spectroscopy. Raman spectroscopy revealed extensive splitting of uranyl vibrations due to the presence of various coordination environments for uranyl moieties. This work highlights the complexity and flexibility of the uranium oxide hydrate system in the natural weathering of uraninite, and sheds light on the possible alteration pathways for spent nuclear fuels under geological disposal conditions.
ISSN:1144-0546
1369-9261
DOI:10.1039/D1NJ05101F