Li Zhuofeng, Piankova Diana, Yang Yi, Kumagai Yuta, Zschiesche Hannes, Jonsson Mats, Tarakina Nadezda V, Soroka Inna L
Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, 10044, Stockholm, Sweden.
Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476, Potsdam, Germany.
Angew Chem Int Ed Engl. 2022 Feb 1;61(6):e202112204. doi: 10.1002/anie.202112204. Epub 2021 Dec 21.
The role of intermediate phases in CeO mesocrystal formation from aqueous Ce solutions subjected to γ-radiation was studied. Radiolytically formed hydroxyl radicals convert soluble Ce into less soluble Ce . Transmission electron microscopy (TEM) and X-ray diffraction studies of samples from different stages of the process allowed the identification of several stages in CeO mesocrystal evolution following the oxidation to Ce : (1) formation of hydrated Ce hydroxides, serving as intermediates in the liquid-to-solid phase transformation; (2) CeO primary particle growth inside the intermediate phase; (3) alignment of the primary particles into "pre-mesocrystals" and subsequently to mesocrystals, guided by confinement of the amorphous intermediate phase and accompanied by the formation of "mineral bridges". Further alignment of the obtained mesocrystals into supracrystals occurs upon slow drying, making it possible to form complex hierarchical architectures.
研究了中间相在经γ辐射的Ce水溶液形成CeO介晶过程中的作用。辐射分解产生的羟基自由基将可溶性Ce转化为难溶性Ce。通过对该过程不同阶段样品的透射电子显微镜（TEM）和X射线衍射研究，确定了Ce氧化为Ce后CeO介晶演化的几个阶段：（1）形成水合Ce氢氧化物，作为液-固相变的中间体；（2）CeO初级粒子在中间相内生长；（3）初级粒子在无定形中间相的限制作用下排列成“前介晶”，随后形成介晶，并伴随着“矿物桥”的形成。所得介晶在缓慢干燥时进一步排列成超晶，从而有可能形成复杂的分级结构。
