Electrochemical and spectrochemical analysis of U(VI) reduction in nitric acid solutions

Wang, Yingcai; Dong, Xue; Liu, Yuhui; Cao, Xiaohong; Chen, Jing; Xu, Chao

doi:10.1016/j.jelechem.2020.114482

Cited by 22 publications

(7 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To guarantee the sustainable development of nuclear energy, the spent nuclear fuel needs to be managed in a safe and economical manner. 1 Zr metal has a small thermal neutron capture cross-sectional area, good mechanical properties, and strong corrosion resistance, 2 so it is widely used in the nuclear industry. For instance, 10 wt % Zr is usually added into metal fuel elements to stabilize the U−Pu alloy, increase the melting point, decrease the chemical interaction between the fuel and the cladding material, 3,4 reduce the expansion coefficient of the fuel, and improve the burnup.…”

Section: ■ Introductionmentioning

confidence: 99%

“…With the shortage of fossil fuels and the aggravation of environmental pollution, especially under the new situation of advocating low-carbon life, nuclear power has gradually become an important direction for global energy development. To guarantee the sustainable development of nuclear energy, the spent nuclear fuel needs to be managed in a safe and economical manner …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Electrochemical Recovering Zr from Molten Salt Using an Fe Electrode

Han

Wang

et al. 2021

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

To recover zirconium (Zr) from LiCl-KCl molten salt, the electro-reduction mechanisms and dynamic and thermodynamic properties of Zr(IV) on W and Fe electrodes were investigated using a series of electrochemical techniques. Zr(IV) was reduced by a continuous two-step process to form metallic Zr on the W electrode and a one-step process to form various Zr–Fe alloy compounds on the Fe film electrode. The deposition potentials pertaining to the formation of various Zr–Fe intermetallics were found more positive than those of Zr(II)/Zr and Zr(IV)/Zr(II)pairs. Furthermore, the dynamic data of the Zr(II)/Zr pair on the W electrode and the ZrFe3/Zr(IV) pair on the Fe film electrode were measured by linear polarization and Tafel methods. The results indicated that, with an increasing temperature, the value of the exchange current density for the two pairs increased, while the charge transfer resistance and transfer coefficient of the two pairs decreased. The thermodynamic data, for instance, the activities of Zr in Zr–Fe alloys and Gibbs free energies of the formation of Zr–Fe intermetallic compounds, were estimated using open-circuit chronopotentiometry. Furthermore, electrochemical recovering Zr was conducted using an Fe electrode by potentiostatic and galvanostatic electrolysis, which proved that the products were only ZrFe2 intermetallic compounds. The recovery efficiencies were 98.05% and 98.97%, respectively.

show abstract

Section: ■ Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Electrochemical Recovering Zr from Molten Salt Using an Fe Electrode

Han

Wang

et al. 2021

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

show abstract

“…However, in environmental conditions in the presence of anaerobic bacteria, chelating agent, or UV light, uranium can be present in the tetravalent state . In the cyclic voltammetry study of UO 2 2+ in the absence of LH 4 , two distinct peaks were observed in the cathodic sweep, which can be attributed to the reduction of UO 2 2+ → UO 2 + and UO 2 + → U 4+ at −0.15 and −0.49 V (vs Ag/AgCl), respectively (Figure ), which is in line with the literature report . In the presence of LH 4 , a broad reduction peak was observed in the cathodic scan at −0.37 V due to the reduction of UO 2 2+ → U 4+ and in the anodic scan the broad peak at +0.87 V (vs Ag/AgCl) was attributed to U 4+ → UO 2 2+ oxidation.…”

Section: Resultsmentioning

confidence: 99%

“…51 In the cyclic voltammetry study of UO 2 2+ in the absence of LH 4 , two distinct peaks were observed in the cathodic sweep, which can be attributed to the reduction of UO 2 2+ → UO 2 + and UO 2 + → U 4+ at −0.15 and −0.49 V (vs Ag/AgCl), respectively (Figure 6), which is in line with the literature report. 52 In the presence of LH 4 , a broad reduction peak was observed in the cathodic scan at −0.37 V due to the reduction of UO 2 2+ → U 4+ and in the anodic scan the broad peak at +0.87 V (vs Ag/AgCl) was attributed to U 4+ → UO 2 2+ oxidation. The absence of the UO 2 2+ → UO 2 + couple in either the cathodic or the UO 2 + → UO 2 2+ couple in the anodic scan suggested rapid disproportionation of UO 2 + .…”

Section: +mentioning

confidence: 92%

Pyridine Diphosphonate Ligand for Stabilization of Tetravalent Uranium and Neptunium in Aqueous Medium under Aerobic Conditions

Verma,

Mahanty,

Bhattacharyya

et al. 2024

Inorg. Chem.

View full text Add to dashboard Cite

Though uranium is usually present in its +6 oxidation state (as uranyl ion) in aqueous solutions, its conversion to oxidation states such as +4 or +5 is a challenging task. Electrochemical reduction and axial oxo activation are the preferred methods to get stable unusual oxidation states of uranium in an aqueous medium. In previous studies, dicarboxylic acid has been used to stabilize UO2 + in aqueous alkaline solutions. In the present work, a diphosphonate ligand was chosen due to its higher complexing ability compared to that of the carboxylate ligands. Neptunium complexation studies with 2,6-pyridinediphosphonic acid (PyPOH) indicated the formation of different species at different pH values and the complexation facilitates disproportionation of NpO2 + to Np4+ and NpO2 2+ at pH 2. Hexavalent actinides form insoluble complexes in aqueous media at pH = 2, as confirmed by UO2 2+ complexation studies. The in situ complexation-driven precipitation resulted in conversion to pure Np4+ in aqueous media as the Np4+-PyPOH complex. A strong complexing ability of the PyPOH ligand toward the Np4+ ion is also seen for the stabilization of the electrochemically generated U4+ in aqueous medium under aerobic conditions. The U4+-PyPOH complex was found to be stable for 3 months. Raman, UV–vis, fluorescence, and cyclic voltametric studies along with density functional theory (DFT) calculations were done to get structural insights into the PyPOH complexes of actinides in different oxidation states.

show abstract

“…[1][2][3] With the accumulation of a large amount of spent fuel, it is essential to develop an effective nuclear fuel cycle for the sustainable development of nuclear energy. 4 Whereas, how to supervise spent fuel safely and economically has become one of serious issues that we must have encountered. 5 Thus, there is an urgent need for spent fuel reprocessing.…”

Section: Introductionmentioning

confidence: 99%

Electrode reaction of Pr on Sn electrode and its electrochemical recovery fromLiCl‐KClmolten salt

et al. 2021

View full text Add to dashboard Cite

To recover Pr from molten chlorides, the electrode reactions of Pr 3+ on Sn-coated W and liquid Sn electrodes were studied by a group of electrochemical techniques. CV and SWV results exhibited that the electrochemical signals pertaining to the formation of Pr-Sn alloy compounds and solid solution appeared at less negative potentials than that of Pr 3+ on W electrode. The thermodynamic data of Pr-Sn alloy compounds and the kinetic parameters for PrSn 3 /Pr 3+ pair were determined employing OCP, LP, and Tafel methods, separately. The measured diffusion coefficient (D) of Pr in liquid Sn metal was 9.40 × 10 −6 cm 2 s −1 . Furthermore, the electrochemical recovering Pr from molten salt was performed using liquid Sn as a working electrode, and the formed Pr-Sn samples characterized by XRD and SEM-EDS were composed of Sn and PrSn 3 phases.

show abstract

Electrochemical and spectrochemical analysis of U(VI) reduction in nitric acid solutions

Cited by 22 publications

References 55 publications

Electrochemical Recovering Zr from Molten Salt Using an Fe Electrode

Electrochemical Recovering Zr from Molten Salt Using an Fe Electrode

Pyridine Diphosphonate Ligand for Stabilization of Tetravalent Uranium and Neptunium in Aqueous Medium under Aerobic Conditions

Electrode reaction of Pr on Sn electrode and its electrochemical recovery fromLiCl‐KClmolten salt

Contact Info

Product

Resources

About