1
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Kurtyka N, van Devener B, Chung BW, McDonald LW. In Situ Liquid Cell Transmission Electron Microscopy Study of Studtite Particle Formation and Growth via Electron Beam Radiolysis. ACS OMEGA 2023; 8:48336-48343. [PMID: 38144047 PMCID: PMC10733958 DOI: 10.1021/acsomega.3c07743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 11/10/2023] [Accepted: 11/15/2023] [Indexed: 12/26/2023]
Abstract
This study presents in situ observations of studtite (UO2O2(H2O)2·2H2O) crystal growth utilizing liquid phase transmission electron microscopy (LP-TEM). Studtite was precipitated from a uranyl nitrate hexahydrate solution using hydrogen peroxide formed by the radiolysis of water in the TEM electron beam. The hydrogen peroxide (H2O2) concentration, directly controlled by the electron beam current, was varied to create local environments of low and high concentrations to compare the impact of the supersaturation ratio on the nucleation and growth mechanisms of studtite particles. The subsequent growth mechanisms were observed in real time by TEM and scanning TEM imaging. After the initial precipitation reaction, a post-mortem TEM analysis was performed on the samples to obtain high-resolution TEM images and selected area electron diffraction patterns to investigate crystallinity as well as energy-dispersive X-ray spectroscopy spectra to ensure that studtite was produced. The results reveal that studtite particles form through various mechanisms based on the concentration ratio of uranyl to H2O2 and that studtite is initially produced through an amorphous intermediary prior to formation of the crystalline material commonly reported in the literature.
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Affiliation(s)
- Nick Kurtyka
- Department
of Nuclear Engineering, University of Utah, 110 Central Campus Dr., Suite 2000, Salt Lake City, Utah 84112, United States
| | - Brian van Devener
- Electron
Microscopy and Surface Analysis Laboratory, University of Utah, Salt Lake
City, Utah 84112, United States
| | - Brandon W. Chung
- Lawrence
Livermore National Laboratory, 7000 East Ave., Livermore, California 94550, United States
| | - Luther W. McDonald
- Department
of Nuclear Engineering, University of Utah, 110 Central Campus Dr., Suite 2000, Salt Lake City, Utah 84112, United States
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2
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Li J, Li L, Jonsson M. Formation and stability of studtite in bicarbonate-containing waters. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 263:115297. [PMID: 37494736 DOI: 10.1016/j.ecoenv.2023.115297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 06/21/2023] [Accepted: 07/21/2023] [Indexed: 07/28/2023]
Abstract
Studtite and meta-studtite are the only two uranyl peroxides found in nature. Sparsely soluble studtite has been found in natural uranium deposits, on the surface of spent nuclear fuel in contact with water and on core material from major nuclear accidents such as Chernobyl. The formation of studtite on the surface of nuclear fuel can have an impact on the release of radionuclides to the biosphere. In this work, we have experimentally studied the formation of studtite as function of HCO3- concentration and pH. The results show that studtite can form at pH ≤ 10 in solutions without added HCO3-. At pH ≤ 7, the precipitate was found to be mainly studtite, while at 8 ≤ pH ≤ 9.8, a mixture of studtite and meta-schoepite was found. Studtite formation from UO22+ and H2O2 was observed at [HCO3-] ≤ 2 mM and studtite was only found to dissolve at [HCO3-] > 2 mM.
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Affiliation(s)
- Junyi Li
- Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal institute of Technology, SE-10044 Stockholm, Sweden.
| | - Lengwan Li
- Department of Fibre and Polymer Technology, Wallenberg Wood Science Center, KTH Royal Institute of Technology, 10044 Stockholm, Sweden
| | - Mats Jonsson
- Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal institute of Technology, SE-10044 Stockholm, Sweden
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3
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Julien PA, Castle G, Theriault J, Kohlgruber TA, Oliver AG, Burns PC. Assembly of Uranyl Peroxides from Ball Milled Solids. Inorg Chem 2022; 61:11319-11324. [PMID: 35830593 DOI: 10.1021/acs.inorgchem.2c01445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mechanochemistry enables transformations of highly insoluble materials such as uranium dioxide or the mineral studtite [(UO2)(O2)(H2O)2]·(H2O)2 into uranyl triperoxide compounds that can subsequently assemble into hydroxide-bridged uranyl peroxide dimers in the presence of lithium hydroxide. Dissolution of these solids in water yields uranyl peroxide nanoclusters including U24, Li24[(UO2)(O2)(OH)]24. Insoluble uranium solids can transform into highly soluble uranyl peroxide phases in the solid state with miniscule quantities of water. Such reactions are potentially applicable to uranium processing in the front and back end of the nuclear fuel cycle.
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Affiliation(s)
- Patrick A Julien
- Department of Civil & Environmental Engineering & Earth Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Grace Castle
- Department of Civil & Environmental Engineering & Earth Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Jordan Theriault
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Tsuyoshi A Kohlgruber
- Department of Civil & Environmental Engineering & Earth Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Allen G Oliver
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Peter C Burns
- Department of Civil & Environmental Engineering & Earth Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States.,Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
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4
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Tsantis ST, Lada ZG, Tzimopoulos DI, Bekiari V, Psycharis V, Raptopoulou CP, Perlepes SP. Two different coordination modes of the Schiff base derived from ortho-vanillin and 2-(2-aminomethyl)pyridine in a mononuclear uranyl complex. Heliyon 2022; 8:e09705. [PMID: 35721682 PMCID: PMC9204727 DOI: 10.1016/j.heliyon.2022.e09705] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/19/2022] [Accepted: 06/07/2022] [Indexed: 11/27/2022] Open
Abstract
This work describes the reaction of the potentially tetradentate Schiff-base ligand N-(2-pyridylmethy)-3-methoxysalicylaldimine (HL) with UO2(O2CMe)2·2H2O and UO2(NO3)2· 6H2O in MeOH in the absence or presence of an external base, respectively. The product from these reactions is the mononuclear complex [UO2(L)2] (1). Its structure has been determined by single-crystal, X-ray crystallography. The anionic ligand adopts two different coordination modes (1.1011, 1.1010; Harris notation) in the complex. The new compound was fully characterized by solid-state (IR, Raman and Photoluminescence spectroscopies) and solution (UV-Vis and 1H NMR spectra, conductivity measurements) techniques.
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Affiliation(s)
- Sokratis T Tsantis
- Department of Chemistry, University of Patras, 26504 Patras, Greece.,Institute of Chemical Engineering Sciences, Foundation for Research and Technology-Hellas (Forth/ICE-HT), Platani, P.O. Box 1414, 26504 Patras, Greece
| | - Zoi G Lada
- Institute of Chemical Engineering Sciences, Foundation for Research and Technology-Hellas (Forth/ICE-HT), Platani, P.O. Box 1414, 26504 Patras, Greece
| | | | - Vlasoula Bekiari
- Department of Crop Science, University of Patras, 30200 Messolonghi, Greece
| | - Vassilis Psycharis
- Institute of Nanoscience and Nanotechnology, NCSR "Demokritos", 15310 Aghia Paraskevi Attikis, Greece
| | - Catherine P Raptopoulou
- Institute of Nanoscience and Nanotechnology, NCSR "Demokritos", 15310 Aghia Paraskevi Attikis, Greece
| | - Spyros P Perlepes
- Department of Chemistry, University of Patras, 26504 Patras, Greece.,Institute of Chemical Engineering Sciences, Foundation for Research and Technology-Hellas (Forth/ICE-HT), Platani, P.O. Box 1414, 26504 Patras, Greece
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5
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Li J, Szabó Z, Jonsson M. Stability of Studtite in Saline Solution: Identification of Uranyl-Peroxo-Halo Complex. Inorg Chem 2022; 61:8455-8466. [PMID: 35608075 PMCID: PMC9175179 DOI: 10.1021/acs.inorgchem.2c00233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
![]()
Hydrogen peroxide
is produced upon radiolysis of water and has
been shown to be the main oxidant driving oxidative dissolution of
UO2-based nuclear fuel under geological repository conditions.
While the overall mechanism and speciation are well known for granitic
groundwaters, considerably less is known for saline waters of relevance
in rock salt or during emergency cooling of reactors using seawater.
In this work, the ternary uranyl–peroxo–chloro and uranyl–peroxo–bromo
complexes were identified using IR, Raman, and nuclear magnetic resonance
(NMR) spectroscopy. Based on Raman spectra, the estimated stability
constants for the identified uranyl–peroxo–chloro ((UO2)(O2)(Cl)(H2O)2–) and uranyl–peroxo–bromo ((UO2)(O2)(Br)(H2O)2–) complexes are
0.17 and 0.04, respectively, at ionic strength ≈5 mol/L. It
was found that the uranyl–peroxo–chloro complex is more
stable than the uranyl–peroxo–bromo complex, which transforms
into studtite at high uranyl and H2O2 concentrations.
Studtite is also found to be dissolved at a high ionic strength, implying
that this may not be a stable solid phase under very saline conditions.
The uranyl–peroxo–bromo complex was shown to facilitate
H2O2 decomposition via a mechanism involving
reactive intermediates. Aqueous
solutions containing UO22+ and H2O2 are stabilized by the presence of
chloride. This is attributed to the formation of uranyl−chloro
and uranyl−peroxo−chloro complexes preventing the precipitation
of studtite. The existence of these complexes was confirmed using
IR, Raman, and NMR spectroscopies.
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Affiliation(s)
- Junyi Li
- Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal institute of Technology, SE-10044 Stockholm, Sweden
| | - Zoltán Szabó
- Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal institute of Technology, SE-10044 Stockholm, Sweden
| | - Mats Jonsson
- Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal institute of Technology, SE-10044 Stockholm, Sweden
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Kravchuk D, Forbes TZ. Thermodynamics and Chemical Behavior of Uranyl Superoxide at Elevated Temperatures. ACS MATERIALS AU 2021; 2:33-44. [PMID: 36855697 PMCID: PMC9928197 DOI: 10.1021/acsmaterialsau.1c00033] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Understanding the alteration mechanisms of UO2-based nuclear fuel has a range of practical implications for both short- and long-term storage of spent fuel rods and environmental ramifications for the mobility of radioactive material at the Chernobyl and Fukushima sites. The major identified alteration phases on the surface of nuclear waste are analogues of schoepite UO3·2H2O, studtite UO2(O2)·4H2O, rutherfordine UO2CO3, and čejkaite Na4UO2(CO3)3. While α-radiolysis has been shown to cause the ingrowth of uranyl peroxide alteration phases, the prevalence of uranyl carbonate phases on solid waste forms has not been mechanistically explained to date, especially since the alteration chemistry is largely affected by the high temperatures of the spent nuclear material. Herein, we demonstrate the first mechanistic link between the formation of the uranyl superoxide (KUPS-1) phase, its reactivity at temperature ranges relevant to the spent nuclear fuel (40-350 °C), and its thermodynamic transformation into a potassium uranyl carbonate mineral phase, agricolaite K4[UO2(CO3)3], using thermogravimetric analysis, calorimetry, vibrational spectroscopy, and powder X-ray diffraction techniques. The thermodynamics data reveal the metastability of the uranyl superoxide KUPS-1 phase through decomposition of the hydrogen peroxide within the solid-state lattice. Increasing the temperature does not result in the breakdown of the superoxide anion bound to the uranyl cation but instead enhances its reactivity in the presence of CO2 gas, resulting in potassium carbonate phases at intermediate temperatures (150 °C) and in uranyl carbonate phases at higher temperatures (350 °C).
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7
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Li J, Szabó Z, Jonsson M. Meta-studtite stability in aqueous solutions. Impact of HCO 3-, H 2O 2 and ionizing radiation on dissolution and speciation. Dalton Trans 2021; 50:6568-6577. [PMID: 33890958 DOI: 10.1039/d1dt00436k] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Two uranyl peroxides meta-studtite and studtite exist in nature and can form as alteration phases on the surface of spent nuclear fuel upon water intrusion in a geological repository. Meta-studtite and studtite have very low solubility and could therefore reduce the reactivity of spent nuclear fuel toward radiolytic oxidants. This would inhibit the dissolution of the fuel matrix and thereby also the spreading of radionuclides. It is therefore important to investigate the stability of meta-studtite and studtite under conditions that may influence their stability. In the present work, we have studied the dissolution kinetics of meta-studtite in aqueous solution containing 10 mM HCO3-. In addition, the influence of the added H2O2 and the impact of γ-irradiation on the dissolution kinetics of meta-studtite were studied. The results are compared to previously published data for studtite studied under the same conditions. 13C NMR experiments were performed to identify the species present in aqueous solution (i.e., carbonate containing complexes). The speciation studies are compared to calculations based on published equilibrium constants. In addition to the dissolution experiments, experiments focussing on the stability of H2O2 in aqueous solutions containing UO22+ and HCO3- were conducted. The rationale for this is that H2O2 was consumed relatively fast in some of the dissolution experiments.
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Affiliation(s)
- Junyi Li
- Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal institute of Technology, SE-10044 Stockholm, Sweden.
| | - Zoltán Szabó
- Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal institute of Technology, SE-10044 Stockholm, Sweden.
| | - Mats Jonsson
- Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal institute of Technology, SE-10044 Stockholm, Sweden.
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8
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Liu C, Yang XX, Niu S, Yi XY, Pan QJ. Occurrence of polyoxouranium motifs in uranyl organic networks constructed by using silicon-centered carboxylate linkers: structures, spectroscopy and computation. Dalton Trans 2020; 49:4155-4163. [DOI: 10.1039/d0dt00379d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Four polyoxouranium-based uranyl carboxylates have been synthesized based on silicon-centered carboxylate linkers. Oligomerization of the uranyl units from tetrameric unit, to octameric motif and ultimately infinite polyoxouranium chain was observed.
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Affiliation(s)
- Chao Liu
- College of Chemistry and Chemical Engineering
- Central South University
- Changsha
- China
| | - Xin-Xue Yang
- College of Chemistry and Chemical Engineering
- Central South University
- Changsha
- China
| | - Shuai Niu
- Key Laboratory of Functional Inorganic Material Chemistry of Education Ministry
- School of Chemistry and Materials Science
- Heilongjiang University
- Harbin 150080
- China
| | - Xiao-Yi Yi
- College of Chemistry and Chemical Engineering
- Central South University
- Changsha
- China
| | - Qing-Jiang Pan
- Key Laboratory of Functional Inorganic Material Chemistry of Education Ministry
- School of Chemistry and Materials Science
- Heilongjiang University
- Harbin 150080
- China
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9
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Lobeck HL, Traustason H, Julien PA, FitzPatrick JR, Mana S, Szymanowski JES, Burns PC. In situ Raman spectroscopy of uranyl peroxide nanoscale cage clusters under hydrothermal conditions. Dalton Trans 2019; 48:7755-7765. [DOI: 10.1039/c9dt01529a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The behaviours of two uranyl peroxide nanoclusters in water heated to 180 °C were examined by in situ Raman spectroscopy.
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Affiliation(s)
- Haylie L. Lobeck
- Department of Civil and Environmental Engineering and Earth Sciences
- University of Notre Dame
- Notre Dame
- USA
| | - Hrafn Traustason
- Department of Chemistry and Biochemistry
- University of Notre Dame
- Notre Dame
- USA
| | | | - John R. FitzPatrick
- Department of Civil and Environmental Engineering and Earth Sciences
- University of Notre Dame
- Notre Dame
- USA
| | - Sara Mana
- Department of Geological Sciences
- Salem State University
- Salem
- USA
| | - Jennifer E. S. Szymanowski
- Department of Civil and Environmental Engineering and Earth Sciences
- University of Notre Dame
- Notre Dame
- USA
| | - Peter C. Burns
- Department of Civil and Environmental Engineering and Earth Sciences
- University of Notre Dame
- Notre Dame
- USA
- Department of Chemistry and Biochemistry
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