Insight into the structure–property relationship of UO2 nanoparticles. Issue 4 (23rd December 2020)

• Record Type: Journal Article
• Authors: Gerber, Evgeny; Romanchuk, Anna Yu.; Weiss, Stephan; Bauters, Stephen; Schacherl, Bianca; Vitova, Tonya; Hübner, René; Shams Aldin Azzam, Salim; Detollenaere, Dirk; Banerjee, Dipanjan; Butorin, Sergei M.; Kalmykov, Stepan N.; Kvashnina, Kristina O.
• Is Part Of: Inorganic chemistry frontiers. Volume 8:Issue 4(2021)
• Page Start: 1102
• Page End: 1110
• Publication Date: 2020-12-23
• Subjects: Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d0qi01140a
• Languages: English
• ISSNs: 2052-1553

Abstract

Abstract : We show that the structural and electronic properties of UO2 NPs (2–3 nm) are similar to those of bulk UO2 under inert conditions, with U(iv ) as the dominating oxidation state, though NPs oxidize with time and under the X-ray beam. 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 microscopy and spectroscopy 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 U4 O9 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 NP properties to PuO2, ThO2 and CeO2 NPs.