INORGANIC CHEMISTRY
·
2025
·
IF 4.7
Huaixin Hao,Yuxiao Guo,Bin Li,Qilong Tang,Yaoyang Liu,Xue Dong,Chao Xu,Jing Chen,Zhipeng Wang
Neptunium (Np), as a critically regarded actinide in nuclear waste, is of great significance for environmental hazard mitigation and the resource-oriented management of nuclear waste. The reduction of Np(V) to Np(IV) represents a pivotal step toward efficient Np recovery. However, this process is profoundly influenced by the intricate redox chemistry of Np itself and the diverse concomitant fission products in spent nuclear fuel, with the underlying mechanistic details remaining inadequately elucidated. In this study, we demonstrated that molybdenum (Mo) and iron (Fe) dramatically accelerated the reduction rate of Np(V) by approximately 2 × 104-fold. Additionally, by integrating analytical techniques including absorption spectroscopy, stopped-flow spectroscopy, inductively coupled plasma–mass spectrometry, and solvent extraction, we deciphered the electron transfer interactions between Mo and Fe, as well as their synergistic catalytic mechanism in driving the Np(V)–Np(IV) conversion. This study not only advances the fundamental understanding of Np redox chemistry in complex nuclear waste matrices but also offers technical support for optimizing nuclear waste treatment protocols.
研究领域:
核化学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL RADIOACTIVITY
·
2023
·
IF 2.3
Yao Yang,Maoyi Luo,Yang Wu,Ni Yuan,Jingjing He,Hongmei Guo,Quan an
A reliable and stable method was developed to accurately analyze neptunium ( 237 Np) and plutonium isotopes in environmental samples using 242 Pu or 236 Pu as a tracer. Key parameters, including the valence adjustment conditions and the stabilities of Pu and Np in the different resins, were investigated using TK200 and TEVA resin. It was found that Pu and Np could be efficiently extracted simultaneously using TK200 resin under the optimal loading conditions (6–12 M HNO 3 ) with the addition of 0.01–0.12 M NaNO 2 for valence adjustment. These isotopes were subsequently stripped out using a solution containing 0.1 M HCl , 0.05 M HF, and 0.01 M NH 2 OH·HCl. The separation efficiencies of Pu and Np were >93%, and the chemical yield ratio between Np and Pu was maintained steady at an average of 1.00 ± 0.03 (n > 50) under the optimal conditions. The analytical method was validated by analyzing environmental soil samples spiked with known amounts of 239 Pu and 237 Np standard solutions or certified reference materials. The measured values of 237 Np, 239 Pu, and 240 Pu obtained by inductively coupled plasma tandem mass spectrometry were consistent with their International Atomic Energy Agency literature values within a 95% confidence interval. These results confirm the reliability and high analytical precision (<6%) of this developed method using Pu as a non-isotopic tracer for monitoring the chemical yield of 237 Np. The developed method can also be used for environmental pollutant monitoring and for tracer studies of the 237 Np and Pu isotopes.
研究领域:
环境科学
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核化学
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分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2020
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IF 3.83
Zi-Jun Wei,Weichao Bao,Shi-Kuan Sun,Lewis R. Blackburn,Sheng-Heng Tan,Laura J. Gardner,Wei-Ming Guo,Fangfang Xu,Neil C. Hyatt,Hua-Tay Lin
Praseodymium-doped zirconolite ceramics targeting nominal composition Ca 1-x Pr x ZrTi 2-5x/3 Al 5x/3 O 7 (x ≤ 0.20, Δx = 0.05) were fabricated by a mixed oxide solid state reaction, at 1350 °C in air for 20 h. Praseodymium (Pr) was employed as a surrogate for neptunium (Np), with Al 3+ co-accommodated to provide charge balance. High-resolution transmission electron microscopy and electron diffraction analyses confirmed that zirconolite crystallised as the 2M monoclinic polytype throughout the phase evolution, with no evidence of transformation to other polytype structures. Phase assemblage and microstructural data were consistent with zirconolite occupying a high fraction of the phase assemblage (> ca . 93 wt.%), alongside a minor secondary perovskite phase at all levels of targeted Pr incorporation. Despite this, it was demonstrated near theoretical density formed through a solid-state fabrication route, and we therefore propose that, through analogy with the corresponding Pr solid solution, zirconolite may be a suitable candidate for the immobilisation of Np-bearing wastes.
研究领域:
材料科学
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核废料管理
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2012
·Vol. 3
·期 5
·1572-1582
·
IF 0
Qing-Jiang Pan,Yong-Ming Wang,Run-Xue Wang,Hong-Yue Wu,Weiting Yang,Zhong-Ming Sun,Hong-Xing Zhang
Relativistic density functional theory was used to explore a series of bisactinyl complexes, [(phen)(AnVIO2)(μ2-F)(F)]2 (An = U (1), Np (2) and Pu (3); phen = phenanthroline; μ2 = doubly bridged), [(phen)(UVO2)(μ2-F)(F)]22− (4), [(phen)(UVIO2)(μ2-X)(X)]2 (X = Cl (5), Br (6) and I (7)), [(L)(UVIO2)(μ2-F)(F)]2 (L = bpy (8), 2NH3 (9) and 2F (10); bpy = 2,2′-bipyridine) and [NH4]4[(F)2(UVIO2)(μ2-F)(F)]2 (11). The effects of varying actinyl ions (UO22+, NpO22+ and PuO22+), oxidation states of uranium (VI and V) and equatorial ligands (phen → bpy → 2NH3 → 2F and F → Cl → Br → I) on the structures and electronic properties of complexes were examined. The calculated distances and bond orders of AnO indicate the partial triple bonding character, and agree with the trends in the AnO stretching vibrational frequencies. The free energies of formation reactions of 1–11 calculated in the aqueous solution demonstrate that 1, 8 and 11 are thermodynamically stable. In this work, we have successfully synthesized 1 and [Me2NH2]4[(F)2(UVIO2)(μ2-F)(F)]2 (12), which is represented by theoretical model complex 11. Their characterizations of the single crystal X-ray diffraction and infrared are consistent with the calculated results; the measured fine-structured fluorescent emissions were assigned as transitions from the UO bonding to the U (f) orbital by analyzing the electronic structure and absorption spectra.
研究领域:
化学
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材料科学
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理论计算
✓ 已验证
产品关联
DOI
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Qi Chen,Baole Li,Junli Wang,Haowei Zhu,Xiwen Chen,Yifu Hu,Jia Zhou,Wentao Wang,Weifang Zheng,Taihong Yan
In this work, the solvent extraction and complexation behaviors of U(VI) by two novel asymmetrical tetra-alkylcarbamides, N,N’-butyl-N,N’-hexylurea ( L1 : SBHU ) and N,N’-butyl-N,N’-pentylurea ( L2 : SBPU ) in HNO 3 media were systematically investigated. Both two ligands extract U(VI) more effectively than other metals such as Pu(IV), Np(IV), and Th(IV) in a wide range of acidity. Under 5 mol/L HNO 3 , D U reached 5.25, while D Pu = 1.08, D Np = 0.11, D Th = 0.13.. Additionally, no third-phase was present by the extraction of highly uranium concentration solution with SBHU even under 7 mol/L HNO 3 after four cycles demonstrating good acid resistance and resistance to the formation of the third phase. Slope analyses and FT-IR indicate that the U(VI) complexes are a form of UO 2 (NO 3 ) 2 ·2 L for the two ligands during the extraction. Additionally, based on the DFT calculations, the NBO analysis, and topological analysis were analyzed in detail. The results demonstrate that the interactions between ligands and U(VI) are shown mainly as ionic characteristics, and the ligand-to-metal charge transfer was also observed. This study enriches the coordination chemistry of actinides: Th(IV), U(VI), Np(IV), Am(III), and Pu(IV) by tetra-alkylcarbamides, which may shed light on the design and synthesis of novel U(VI) selective ligands.
研究领域:
配位化学
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锕系元素化学
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溶剂萃取
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理论化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）