Gerber Evgeny, Romanchuk Anna Yu, Pidchenko Ivan, Amidani Lucia, Rossberg Andre, Hennig Christoph, Vaughan Gavin B M, Trigub Alexander, Egorova Tolganay, Bauters Stephen, Plakhova Tatiana, Hunault Myrtille O J Y, Weiss Stephan, Butorin Sergei M, Scheinost Andreas C, Kalmykov Stepan N, Kvashnina Kristina O
The Rossendorf Beamline at ESRF - The European Synchrotron, CS40220, 38043 Grenoble Cedex 9, France.
Nanoscale. 2020 Sep 21;12(35):18039-18048. doi: 10.1039/d0nr03767b. Epub 2020 Jul 10.
The nanoscience field often produces results more mystifying than any other discipline. It has been argued that changes in the plutonium dioxide (PuO) particle size from bulk to nano can have a drastic effect on PuO properties. Here we report a full characterization of PuO nanoparticles (NPs) at the atomic level and probe their local and electronic structures by a variety of methods available at the synchrotron, including extended X-ray absorption fine structure (EXAFS) at the Pu L edge, X-ray absorption near edge structure (XANES) in high energy resolution fluorescence detection (HERFD) mode at the Pu L and M edges, high energy X-ray scattering (HEXS) and X-ray diffraction (XRD). The particles were synthesized from precursors with different oxidation states of plutonium (III, IV, and V) under various environmentally and waste storage relevant conditions (pH 8 and pH > 10). Our experimental results analyzed with state-of-the-art theoretical approaches demonstrate that well dispersed, crystalline NPs with a size of ∼2.5 nm in diameter are always formed in spite of diverse chemical conditions. Identical crystal structures and the presence of only the Pu(iv) oxidation state in all NPs, reported here for the first time, indicate that the structure of PuO NPs is very similar to that of the bulk PuO. All methods give complementary information and show that investigated fundamental properties of PuO NPs, rather than being exotic, are very similar to those of the bulk PuO.
纳米科学领域常常产生比其他任何学科都更令人费解的结果。有人认为，二氧化钚（PuO）颗粒尺寸从块状变为纳米级会对PuO的性质产生巨大影响。在此，我们报告了PuO纳米颗粒（NPs）在原子水平上的全面表征，并通过同步加速器可用的多种方法探究其局部结构和电子结构，包括Pu L边的扩展X射线吸收精细结构（EXAFS）、Pu L和M边在高能量分辨率荧光检测（HERFD）模式下的X射线吸收近边结构（XANES）、高能X射线散射（HEXS）和X射线衍射（XRD）。这些颗粒是在各种与环境和废物储存相关的条件（pH 8和pH > 10）下，由具有不同氧化态（III、IV和V）的钚前驱体合成的。我们用最先进的理论方法分析实验结果表明，尽管化学条件各不相同，但总是会形成直径约为2.5 nm的分散良好的结晶NPs。本文首次报道，所有NPs具有相同的晶体结构且仅存在Pu(iv)氧化态，这表明PuO NPs的结构与块状PuO非常相似。所有方法都提供了互补信息，并表明所研究的PuO NPs的基本性质并非奇特，而是与块状PuO的性质非常相似。
