Synthesis and Morphological Control of UO₂F₂Particulates

Abstract

Uranium-based microspheres are of interest due to their potential applications as targets for medical isotopes production, as fuel for nuclear reactors, and as standardized materials for nuclear forensics. Here, for the first time, UO2F2 microspheres (1–2 μm) have been prepared from the reaction between UO3 microspheres and AgHF2 in an autoclave. In this preparation, a new fluorination method has been applied, and HF(g)produced in situ from the thermal decomposition of AgHF2 and NH4HF2was used as the fluorinating agent. The microspheres were characterized by powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). Diffraction results indicated that the reaction performed with AgHF2 at 200 °C led to anhydrous UO2F2 microspheres, while at 150 °C, hydrated UO2F2 microspheres were obtained. Meanwhile, NH4HF2 led to the formation of contaminated products as driven by the formation of volatile species.

Tailoring Triuranium Octoxide into Multidimensional Uranyl Fluoride Micromaterials

“…UO 2 F 2 ms has already been reported and was prepared from the reaction of UO 3 ms with SBF. 29 Here, we report the formation of UO 2 F 2 ms by two other routes: the reactions of U 3 O 8 ms with ABF and SBF.…”

“…For actinides, one simple chemical transformation is the replacement of O by F atoms in oxide materials using a solid–gas reaction . Recently, we reported one such approach and prepared uranyl difluoride microspheres from the reaction of UO 3 ms and HF (g) produced from the decomposition of silver bifluoride (SBF) . The motivation for studying uranyl difluoride is that the material is relevant to nuclear and safeguard applications (e.g., as an intermediate for UF 6 and UO 2 conversion). − Also, fluorinated U materials (UO 2 F 2 , UF 4 ) exhibit photoluminescent properties , that are studied to improve radiation detection technology, such as the detection of leaking UF 6 cylinders and sensitive low-dose measurements …”