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Kuzenkova AS, Plakhova TV, Nevolin IM, Kulikova ES, Trigub AL, Yapaskurt VO, Shaulskaya MD, Tsymbarenko DM, Romanchuk AY, Kalmykov SN. Formation of Neptunium(V) Carbonates: Examining the Forceful Influence of Alkali and Alkaline Earth Cations. Inorg Chem 2023; 62:21025-21035. [PMID: 38091513 DOI: 10.1021/acs.inorgchem.3c02737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2023]
Abstract
Herein, neptunium(V) carbonates containing sodium or potassium cations were synthesized via chemical precipitation. Various techniques such as scanning electron microscopy, energy-dispersive X-ray spectroscopy, thermogravimetry combined with differential scanning calorimetry, X-ray diffraction, and X-ray absorption spectroscopy were used to analyze the microstructures and elemental compositions of these samples. The crystal structures of hydrated NaNpO2CO3·3H2O (P1, a = 4.3420(2) Å, b = 4.8962(2) Å, c = 10.0933(11) Å, α = 91.014(7)°, β = 77.834(11)°, and γ = 90.004(10)°) and KNpO2CO3 (P63/mmc, a = b = 5.0994(2) Å, c = 10.2210(15) Å) were determined for the first time using the Rietveld method. The synthesized carbonates exhibited distinct structural features and decomposition behaviors, as demonstrated through thermogravimetry analysis, which revealed the presence of crystalline hydrate water in sodium neptunium(V) carbonate. Furthermore, calcium-containing neptunium(V) carbonates were synthesized and characterized. Samples with the general composition Ca0.5NpO2CO3 were obtained using the ion exchange method and chemical precipitation from solutions containing competing cations (Ca2+, Na+, K+, and Mg2+). The synthesis conditions notably affected the diffraction patterns of the obtained calcium neptunium(V) carbonates. This investigation enhances our understanding of the structural properties and thermodynamic stability of neptunium(V) carbonates in the presence of diverse cations commonly found under radioactive waste disposal conditions.
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Affiliation(s)
| | - Tatiana V Plakhova
- Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
| | - Iurii M Nevolin
- Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninsky Prospect 31 Bld. 4, 119071 Moscow, Russia
| | - Elizaveta S Kulikova
- National Research Centre ⟨⟨Kurchatov Institute⟩⟩, Akademika Kurchatova pl. 1, 123182 Moscow, Russia
| | - Alexander L Trigub
- Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
- National Research Centre ⟨⟨Kurchatov Institute⟩⟩, Akademika Kurchatova pl. 1, 123182 Moscow, Russia
| | | | - Maria D Shaulskaya
- Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
| | | | - Anna Yu Romanchuk
- Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
| | - Stepan N Kalmykov
- Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
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Boulanger N, Li G, Bakhiia T, Maslakov KI, Romanchuk AY, Kalmykov SN, Talyzin AV. Super-oxidized "activated graphene" as 3D analogue of defect graphene oxide: Oxidation degree vs U(VI) sorption. J Hazard Mater 2023; 457:131817. [PMID: 37327606 DOI: 10.1016/j.jhazmat.2023.131817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 06/05/2023] [Accepted: 06/07/2023] [Indexed: 06/18/2023]
Abstract
Porous carbons are not favorable for sorption of heavy metals and radionuclides due to absence of suitable binding sites. In this study we explored the limits for surface oxidation of "activated graphene" (AG), porous carbon material with the specific surface area of ∼2700 m2/g produced by activation of reduced graphene oxide (GO). Set of "Super-Oxidized Activated Graphene" (SOAG) materials with high abundance of carboxylic groups on the surface were produced using "soft" oxidation. High degree of oxidation comparable to standard GO (C/O=2.3) was achieved while keeping 3D porous structure with specific surface area of ∼700-800 m2/. The decrease in surface area is related to the oxidation-driven collapse of mesopores while micropores showed higher stability. The increase in the oxidation degree of SOAG is found to result in progressively higher sorption of U(VI), mostly related to the increase in abundance of carboxylic groups. The SOAG demonstrated extraordinarily high sorption of U(VI) with the maximal capacity up to 5400 μmol/g, that is 8.4 - fold increase compared to non-oxidized precursor AG, ∼50 -fold increase compared to standard graphene oxide and twice higher than extremely defect-rich graphene oxide. The trends revealed here show a way to further increase sorption if similar oxidation degree is achieved with smaller sacrifice of surface area.
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Affiliation(s)
| | - Gui Li
- Department of Physics, Umeå University, S-90187 Umeå, Sweden
| | - Tamuna Bakhiia
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, Moscow 119991, Russia
| | - Konstantin I Maslakov
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, Moscow 119991, Russia
| | - Anna Yu Romanchuk
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, Moscow 119991, Russia
| | - Stepan N Kalmykov
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, Moscow 119991, Russia.
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Romanchuk AY, Plakhova TV, Konyukhova AD, Smirnova A, Kozlov DA, Novichkov DA, Trigub AL, Kalmykov SN. Oxidation and Nanoparticle Formation during Ce(III) Sorption onto Minerals. Environ Sci Technol 2023; 57:5243-5251. [PMID: 36940242 DOI: 10.1021/acs.est.2c08921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The sorption of Ce(III) on three abundant environmental minerals (goethite, anatase, and birnessite) was investigated. Batch sorption experiments using a radioactive 139Ce tracer were performed to investigate the key features of the sorption process. Differences in sorption kinetics and changes in oxidation states were found in the case of the sorption of Ce(III) on birnessite compared to that on other minerals. Speciation of cerium onto all of the studied minerals was investigated using spectral and microscopic methods: high-resolution transmission electron microscopy (HRTEM), electron energy loss spectroscopy (EELS), and X-ray absorption spectroscopy (XAS) in conjunction with theoretical calculations. It was found that during the sorption process onto birnessite, Ce(III) was oxidized to Ce(IV), while the Ce(III) on goethite and anatase surfaces remained unchanged. Oxidation of Ce(III) by sorption on birnessite was also accompanied by the formation of CeO2 nanoparticles on the mineral surface, which depended on the initial cerium concentration and pH value.
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Affiliation(s)
- Anna Yu Romanchuk
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, 119991 Moscow, Russia
| | - Tatiana V Plakhova
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, 119991 Moscow, Russia
| | - Anastasiia D Konyukhova
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, 119991 Moscow, Russia
| | - Anastasiia Smirnova
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, 119991 Moscow, Russia
| | - Daniil A Kozlov
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, 119991 Moscow, Russia
- Kurnakov Institute of General and Inorganic Chemistry, Moscow, Leninskii prosp. 31, 119071 Moscow, Russia
| | - Daniil A Novichkov
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, 119991 Moscow, Russia
| | - Alexander L Trigub
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, 119991 Moscow, Russia
- National Research Centre Kurchatov Institute, Akademika Kurchatova pl. 1, 123182 Moscow, Russia
| | - Stepan N Kalmykov
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, 119991 Moscow, Russia
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Gerber E, Romanchuk AY, Weiss S, Kuzenkova A, Hunault MOJY, Bauters S, Egorov A, Butorin SM, Kalmykov SN, Kvashnina KO. To form or not to form: PuO 2 nanoparticles at acidic pH. Environ Sci Nano 2022; 9:1509-1518. [PMID: 35520632 PMCID: PMC9009106 DOI: 10.1039/d1en00666e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 02/08/2022] [Indexed: 11/25/2022]
Abstract
The aim of this study is to synthesize PuO2 nanoparticles (NPs) at low pH values and characterize the materials using laboratory and synchrotron-based methods. Properties of the PuO2 NPs formed under acidic conditions (pH 1-4) are explored here at the atomic scale. High-resolution transmission electron microscopy (HRTEM) is applied to characterize the crystallinity, morphology and size of the particles. It is found that 2 nm crystalline NPs are formed with a PuO2 crystal structure. High energy resolution fluorescence detected (HERFD) X-ray absorption spectroscopy at the Pu M4 edge has been used to identify the Pu oxidation states and recorded data are analysed using the theory based on the Anderson impurity model (AIM). The experimental data obtained on NPs show that the Pu(iv) oxidation state dominates in all NPs formed at pH 1-4. However, the suspension at pH 1 demonstrates the presence of Pu(iii) and Pu(vi) in addition to the Pu(iv), which is associated with redox dissolution of PuO2 NPs under acidic conditions. We discuss in detail the mechanism that affects the PuO2 NPs synthesis under acidic conditions and compare it with one in neutral and alkaline conditions. Hence, the results shown here, together with the first Pu M4 HERFD data on PuF3 and PuF4 compounds, are significant for the colloid facilitated transport governing the migration of plutonium in a subsurface environment.
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Affiliation(s)
- Evgeny Gerber
- Lomonosov Moscow State University, Department of Chemistry 119991 Moscow Russia
- The Rossendorf Beamline at ESRF - The European Synchrotron CS40220 38043 Grenoble Cedex 9 France
- Helmholtz Zentrum Dresden-Rossendorf (HZDR), Institute of Resource Ecology PO Box 510119 01314 Dresden Germany
| | - Anna Yu Romanchuk
- Lomonosov Moscow State University, Department of Chemistry 119991 Moscow Russia
| | - Stephan Weiss
- Helmholtz Zentrum Dresden-Rossendorf (HZDR), Institute of Resource Ecology PO Box 510119 01314 Dresden Germany
| | | | | | - Stephen Bauters
- The Rossendorf Beamline at ESRF - The European Synchrotron CS40220 38043 Grenoble Cedex 9 France
- Helmholtz Zentrum Dresden-Rossendorf (HZDR), Institute of Resource Ecology PO Box 510119 01314 Dresden Germany
| | - Alexander Egorov
- Lomonosov Moscow State University, Department of Chemistry 119991 Moscow Russia
| | - Sergei M Butorin
- Condensed Matter Physics of Energy Materials, X-ray Photon Science, Department of Physics and Astronomy, Uppsala University P.O. Box 516 SE-751 20 Uppsala Uppsala Sweden
| | - Stepan N Kalmykov
- Lomonosov Moscow State University, Department of Chemistry 119991 Moscow Russia
| | - Kristina O Kvashnina
- Lomonosov Moscow State University, Department of Chemistry 119991 Moscow Russia
- The Rossendorf Beamline at ESRF - The European Synchrotron CS40220 38043 Grenoble Cedex 9 France
- Helmholtz Zentrum Dresden-Rossendorf (HZDR), Institute of Resource Ecology PO Box 510119 01314 Dresden Germany
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Rzhevskaia AV, Romanchuk AY, Vlasova IE, Semenkova AS, Trigub AL, Svetogorov RD, Yapaskurt VO, Paretskov EN, Kalmykov SN. Partitioning of uranium in contaminated bottom sediments: The meaning of fractionation. J Environ Radioact 2021; 229-230:106539. [PMID: 33493873 DOI: 10.1016/j.jenvrad.2021.106539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 12/01/2020] [Accepted: 01/12/2021] [Indexed: 06/12/2023]
Abstract
Sequential extraction tests were used to study partitioning of U in the bottom sediments of two reservoirs that have been used for the temporary storage of nuclear waste at the "Mining and Chemical Combine" (Zheleznogorsk, Krasnoyarsk region, Russia). Various sequential extraction protocols were applied to the bottom sediment samples and the results compared with those obtained for laboratory-prepared simulated samples with different speciation and partitioning, e.g., U(VI) sorbed onto various inorganic minerals and organic matter, as well as uranium oxides. The distributions of uranium in fractions extracted from simulated and actual contaminated samples were compared to shed light on the speciation of U in the bottom sediments. X-ray absorption spectroscopy, X-ray diffraction, and scanning electron microscopy were also used to analyze the partitioning of U in contaminated sediments. We also compared the results obtained using the spectroscopic and microscopic techniques, as well as sequential extraction.
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Affiliation(s)
| | - Anna Yu Romanchuk
- Lomonosov Moscow State University, Leninskie Gory, Moscow, 119991, Russia.
| | - Irina E Vlasova
- Lomonosov Moscow State University, Leninskie Gory, Moscow, 119991, Russia
| | - Anna S Semenkova
- Lomonosov Moscow State University, Leninskie Gory, Moscow, 119991, Russia
| | | | | | | | - Evgeny N Paretskov
- FSUE "Mining and Chemical Combine", Zheleznogorsk, Krasnoyarsk Region, Russia
| | - Stepan N Kalmykov
- Lomonosov Moscow State University, Leninskie Gory, Moscow, 119991, Russia; National Research Centre "Kurchatov Institute", Moscow, Russia
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6
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Amidani L, Vaughan GBM, Plakhova TV, Romanchuk AY, Gerber E, Svetogorov R, Weiss S, Joly Y, Kalmykov SN, Kvashnina KO. The Application of HEXS and HERFD XANES for Accurate Structural Characterisation of Actinide Nanomaterials: The Case of ThO 2. Chemistry 2020; 27:5. [PMID: 33210366 DOI: 10.1002/chem.202004684] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Invited for the cover of this issue is Lucia Amidani and co-workers from the The European Synchrotron, Helmholtz Zentrum Dresden-Rossendorf, Lomonosov Moscow State University, Kurchatov Institute, and the Université Grenoble Alpes. The image depicts the atomic structure of the sample being viewed through "atomic googles", which represent the X-ray techniques used in this work. Read the full text of the article at 10.1002/chem.202003360.
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Affiliation(s)
- Lucia Amidani
- The Rossendorf Beamline at ESRF, The European Synchrotron, CS40220, 38043, Grenoble Cedex 9, France.,Institute of Resource Ecology, Helmholtz Zentrum Dresden-Rossendorf (HZDR), PO Box 510119, 01314, Dresden, Germany
| | - Gavin B M Vaughan
- ESRF-The European Synchrotron, CS40220, 38043, Grenoble Cedex 9, France
| | - Tatiana V Plakhova
- Department of Chemistry, Lomonosov Moscow State University, 119991, Moscow, Russia
| | - Anna Yu Romanchuk
- Department of Chemistry, Lomonosov Moscow State University, 119991, Moscow, Russia
| | - Evgeny Gerber
- The Rossendorf Beamline at ESRF, The European Synchrotron, CS40220, 38043, Grenoble Cedex 9, France.,Department of Chemistry, Lomonosov Moscow State University, 119991, Moscow, Russia
| | - Roman Svetogorov
- National Research Centre "Kurchatov Institute", 123182, Moscow, Russia
| | - Stephan Weiss
- Institute of Resource Ecology, Helmholtz Zentrum Dresden-Rossendorf (HZDR), PO Box 510119, 01314, Dresden, Germany
| | - Yves Joly
- CNRS, Grenoble INP, Institut Néel, Université Grenoble Alpes, 38042, Grenoble, France
| | - Stepan N Kalmykov
- Department of Chemistry, Lomonosov Moscow State University, 119991, Moscow, Russia
| | - Kristina O Kvashnina
- The Rossendorf Beamline at ESRF, The European Synchrotron, CS40220, 38043, Grenoble Cedex 9, France.,Institute of Resource Ecology, Helmholtz Zentrum Dresden-Rossendorf (HZDR), PO Box 510119, 01314, Dresden, Germany
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7
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Gerber E, Romanchuk AY, Pidchenko I, Amidani L, Rossberg A, Hennig C, Vaughan GBM, Trigub A, Egorova T, Bauters S, Plakhova T, Hunault MOJY, Weiss S, Butorin SM, Scheinost AC, Kalmykov SN, Kvashnina KO. The missing pieces of the PuO 2 nanoparticle puzzle. Nanoscale 2020; 12:18039-18048. [PMID: 32648876 DOI: 10.1039/d0nr03767b] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The nanoscience field often produces results more mystifying than any other discipline. It has been argued that changes in the plutonium dioxide (PuO2) particle size from bulk to nano can have a drastic effect on PuO2 properties. Here we report a full characterization of PuO2 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 L3 edge, X-ray absorption near edge structure (XANES) in high energy resolution fluorescence detection (HERFD) mode at the Pu L3 and M4 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 PuO2 NPs is very similar to that of the bulk PuO2. All methods give complementary information and show that investigated fundamental properties of PuO2 NPs, rather than being exotic, are very similar to those of the bulk PuO2.
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Affiliation(s)
- Evgeny Gerber
- The Rossendorf Beamline at ESRF - The European Synchrotron, CS40220, 38043 Grenoble Cedex 9, France.
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Kvashnina KO, Romanchuk AY, Pidchenko I, Amidani L, Gerber E, Trigub A, Rossberg A, Weiss S, Popa K, Walter O, Caciuffo R, Scheinost AC, Butorin SM, Kalmykov SN. A Novel Metastable Pentavalent Plutonium Solid Phase on the Pathway from Aqueous Plutonium(VI) to PuO 2 Nanoparticles. Angew Chem Int Ed Engl 2019; 58:17558-17562. [PMID: 31621992 PMCID: PMC6900038 DOI: 10.1002/anie.201911637] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Indexed: 11/10/2022]
Abstract
Here we provide evidence that the formation of PuO2 nanoparticles from oxidized PuVI under alkaline conditions proceeds through the formation of an intermediate PuV solid phase, similar to NH4PuO2CO3, which is stable over a period of several months. For the first time, state‐of‐the‐art experiments at Pu M4 and at L3 absorption edges combined with theoretical calculations unambiguously allow to determine the oxidation state and the local structure of this intermediate phase.
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Affiliation(s)
- Kristina O Kvashnina
- Institute of Resource Ecology, Helmholtz Zentrum Dresden-Rossendorf (HZDR), PO Box 510119, 01314, Dresden, Germany.,The Rossendorf Beamline at ESRF, The European Synchrotron, CS40220, 38043, Grenoble Cedex 9, France
| | - Anna Yu Romanchuk
- Department of Chemistry, Lomonosov Moscow State University, 119991, Moscow, Russia
| | - Ivan Pidchenko
- Institute of Resource Ecology, Helmholtz Zentrum Dresden-Rossendorf (HZDR), PO Box 510119, 01314, Dresden, Germany.,The Rossendorf Beamline at ESRF, The European Synchrotron, CS40220, 38043, Grenoble Cedex 9, France
| | - Lucia Amidani
- Institute of Resource Ecology, Helmholtz Zentrum Dresden-Rossendorf (HZDR), PO Box 510119, 01314, Dresden, Germany.,The Rossendorf Beamline at ESRF, The European Synchrotron, CS40220, 38043, Grenoble Cedex 9, France
| | - Evgeny Gerber
- Institute of Resource Ecology, Helmholtz Zentrum Dresden-Rossendorf (HZDR), PO Box 510119, 01314, Dresden, Germany.,The Rossendorf Beamline at ESRF, The European Synchrotron, CS40220, 38043, Grenoble Cedex 9, France.,Department of Chemistry, Lomonosov Moscow State University, 119991, Moscow, Russia
| | - Alexander Trigub
- National Research Centre "Kurchatov Institute", 123182, Moscow, Russia
| | - Andre Rossberg
- Institute of Resource Ecology, Helmholtz Zentrum Dresden-Rossendorf (HZDR), PO Box 510119, 01314, Dresden, Germany.,The Rossendorf Beamline at ESRF, The European Synchrotron, CS40220, 38043, Grenoble Cedex 9, France
| | - Stephan Weiss
- The Rossendorf Beamline at ESRF, The European Synchrotron, CS40220, 38043, Grenoble Cedex 9, France
| | - Karin Popa
- Directorate for Nuclear Safety and Security, European Commission, Joint Research Centre, Postfach 2340, 76215, Karlsruhe, Germany
| | - Olaf Walter
- Directorate for Nuclear Safety and Security, European Commission, Joint Research Centre, Postfach 2340, 76215, Karlsruhe, Germany
| | - Roberto Caciuffo
- Directorate for Nuclear Safety and Security, European Commission, Joint Research Centre, Postfach 2340, 76215, Karlsruhe, Germany
| | - Andreas C Scheinost
- Institute of Resource Ecology, Helmholtz Zentrum Dresden-Rossendorf (HZDR), PO Box 510119, 01314, Dresden, Germany.,The Rossendorf Beamline at ESRF, The European Synchrotron, CS40220, 38043, Grenoble Cedex 9, France
| | - Sergei M Butorin
- Department of Physics and Astronomy, Molecular and Condensed Matter Physics, Uppsala University, P.O. Box 516, Uppsala, Sweden
| | - Stepan N Kalmykov
- Department of Chemistry, Lomonosov Moscow State University, 119991, Moscow, Russia.,National Research Centre "Kurchatov Institute", 123182, Moscow, Russia
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9
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Plakhova TV, Romanchuk AY, Butorin SM, Konyukhova AD, Egorov AV, Shiryaev AA, Baranchikov AE, Dorovatovskii PV, Huthwelker T, Gerber E, Bauters S, Sozarukova MM, Scheinost AC, Ivanov VK, Kalmykov SN, Kvashnina KO. Towards the surface hydroxyl species in CeO 2 nanoparticles. Nanoscale 2019; 11:18142-18149. [PMID: 31555787 DOI: 10.1039/c9nr06032d] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Understanding the complex chemistry of functional nanomaterials is of fundamental importance. Controlled synthesis and characterization at the atomic level is essential to gain deeper insight into the unique chemical reactivity exhibited by many nanomaterials. Cerium oxide nanoparticles have many industrial and commercial applications, resulting from very strong catalytic, pro- and anti-oxidant activity. However, the identity of the active species and the chemical mechanisms imparted by nanoceria remain elusive, impeding the further development of new applications. Here, we explore the behavior of cerium oxide nanoparticles of different sizes at different temperatures and trace the electronic structure changes by state-of-the-art soft and hard X-ray experiments combined with computational methods. We confirm the absence of the Ce(iii) oxidation state at the surface of CeO2 nanoparticles, even for particles as small as 2 nm. Synchrotron X-ray absorption experiments at Ce L3 and M5 edges, combined with X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and small angle X-ray scattering (SAXS) and theoretical calculations demonstrate that in addition to the nanoceria charge stability, the formation of hydroxyl groups at the surface profoundly affects the chemical performance of these nanomaterials.
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Affiliation(s)
- Tatiana V Plakhova
- Lomonosov Moscow State University, Department of Chemistry, Leninskije Gory 1, Moscow, Russia
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