Exploring the influence of pH on the structural intricacies of uranium oxide hydrates containing both Cd(ii) and K(i) ions
Loading...
Date
2023-05-28
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Royal Society of Chemistry
Abstract
We report the synthesis of two new dual-cation uranium oxide hydrate (UOH) materials, containing both Cd2+ and K+ ions, along wxrith their characterisation by means of single-crystal X-ray diffraction and a range of other structural and spectroscopic techniques. The materials were found to differ in structures, topology and uranium to cation ratios, with the layered UOH-Cd crystallising in a plate morphology and containing a U : Cd : K ratio of 3 : 1.5 : 1. Conversely, the framework-type UOF-Cd incorporates much less Cd, with a U : Cd : K ratio of 4.4 : 0.2 : 1 and is found as needle-like crystals. A common feature in both structures is the presence of β-U3O8 type layers with a distinct uranium centre which lacks the expected uranyl bonds, highlighting the importance of the β-U3O8 layer in the subsequent self-assembly and preferential formation of a variety of structural types. Most importantly, by exploiting the additional flexibility provided by monovalent cation species (i.e., K+) as secondary metal cations to synthesise these novel dual-cation materials, this work highlights the potential for broadening the scope of viable synthetic UOH phases towards furthering the understanding of these systems in their roles as alteration products in the surrounds of spent nuclear fuel in deep geological repositories. © The Authors - Open Access CC BY Licence
Description
We would like to thank I. Karatchevtseva for Raman measurement, the Nuclear Science and Technology (NST) at ANSTO for synthesis and characterization of materials. The crystallographic data for compounds UOH-Cd and UOF-Cd were collected on the MX2 beamline at the Australian Synchrotron, a part of ANSTO, and made use of the Australian Cancer Research Foundation (ACRF) detector.
Keywords
Uranium oxides, Cadmium, Potassium, X-ray diffraction, Crystals, Layers, Cations, Spent fuels, Geologic deposits
Citation
Ablott, T. A., Lu, K. T., Wei, T., & Zhang, Y. (2023). Exploring the influence of pH on the structural intricacies of uranium oxide hydrates containing both Cd(ii) and K(i) ions [10.1039/D3DT00630A]. Dalton Transactions, 52(20), 6629-6640.doi:10.1039/D3DT00630A