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arXiv · 2102.11643

Insight into the structure-property relation of UO2 nanoparticles

Evgeny Gerber·Anna Yu. Romanchuk·Stephan Weiss·Stephen Bauters·Bianca Schacherl·Tonya Vitova·René Hübner·Salim Shams Aldin Azzam·Dirk Detollenaere·Dipanjan Banerjee·Sergei M. Butorin·Stepan N. Kalmykov·Kristina O. Kvashnina
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Abstract

Highly crystalline UO2 nanoparticles (NPs) with sizes of 2-3 nm were produced by fast chemical deposition of uranium(IV) under reducing conditions at pH 8-11. The particles were then characterized by microscopic and spectroscopic techniques including high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), high-energy resolution fluorescence detection (HERFD) X-ray absorption spectroscopy at the U M4 edge and extended X-ray absorption fine structure (EXAFS) spectroscopy at the U L3 edge. The results of this investigation show that despite U(IV) being the dominant oxidation state of the freshly prepared UO2 NPs, they oxidize to U4O9 with time and under the X-ray beam, indicating the high reactivity of U(IV) under these conditions. Moreover, it was found that the oxidation process of NPs is accompanied by their growth in size to 6 nm. We highlight here the major differences and similarities of the UO2 NPs properties with PuO2, ThO2 and CeO2 NPs.

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Evgeny Gerber, Anna Yu. Romanchuk, Stephan Weiss, Stephen Bauters, Bianca Schacherl, Tonya Vitova, René Hübner, Salim Shams Aldin Azzam, Dirk Detollenaere, Dipanjan Banerjee, Sergei M. Butorin, Stepan N. Kalmykov, Kristina O. Kvashnina. 2021-02-23. Insight into the structure-property relation of UO2 nanoparticles. https://doi.org/10.1039/d0qi01140a

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