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Radioactive Cs+ and I− ions are major components of nuclear wastewater, typically existing as counter ions. Due to their high water solubility and mobility, these ions can spread through contaminated water and soil into ecosystems, necessitating continuous removal and management. In this study, we synthesized a reusable bifunctional Ni@Pt/K2NiFe(CN)6 composite that can simultaneously remove radioactive Cs+ and I− ions and, for the first time, enable their separate recovery in aqueous solutions. In this material, K2NiFe(CN)6 acted as an electrochemically switched ion exchanger, controlling the adsorption/desorption of Cs+, while Pt enabled the spontaneous adsorption and electrochemical desorption of I−, and the magnetic Ni core allowed for efficient adsorbent recovery. The adsorption isotherms of both Cs+ and I− were best fitted using the Langmuir model, and the corresponding adsorption capacities were comparable to those of conventional adsorbents used for the separate removal of Cs+ and I−. Furthermore, the composite demonstrated stability over 100 sorption cycles, maintaining high recovery efficiencies of 97.9 % for Cs+ and 99.7 % for I−, thereby proving its reusability. Thus, the developed composite holds great promise for radioactive wastewater treatment and environmental restoration.

A microelectrode is useful to determine electrochemical parameters such as diffusion coefficient, exchange current density, and Tafel slope without the limitations of ion diffusion. This study aims to develop a new microelectrode for use in high-temperature molten salts, which has been evaluated by determining the parameters of the Sm(III)/Sm(II) reaction in a LiCl–KCl eutectic molten salt. The electrochemical and kinetic properties of the samarium ion in the temperature range 723–823 K were calculated using the limiting current from cyclic voltammograms and the Allen–Hickling equation. The results imply that kinetic parameters (exchange current density and charge transfer coefficient) critical for designing pyroprocesses can be obtained using the developed microelectrode.

This study reports on the dissolution behavior of SrO in LiCl at varying SrO concentrations from low concentrations to excess. The amount of SrO dissolved in the molten salt and the species present upon cooling were determined. The thermal behavior of LiCl containing various concentrations of SrO was investigated. The experimental results were compared with results from the simulated results using the HSC Chemistry software package. Although the reaction of SrO with LiCl in the standard state at 650 °C has a slightly positive Gibbs free energy, SrO was found to be highly soluble in LiCl. Experimentally determined SrO concentrations were found to be considerably higher than those present in used nuclear fuel (

Nitrate adsorption and reduction on Cu(100) in acidic solution is examined. Results reveal that both nitrate and nitrite are twofold coordinated to the Cu(100) surface.

Using cyclic voltammetry and UV-vis absorption spectroscopic methods, we studied the precipitation reactions of trivalent uranium and lanthanides (Nd, Ce, and La)with the oxide ion in LiCl-KClmolten salts, which are likely side reactions during the electrorefining process for nuclear fuel treatment. The in situ electrochemical and spectroscopic monitoring demonstrated that U3+ consumed O2- with the mole ratio of 2:1, whereas the lanthanide ions reacted with O2- with the mole ratio of 1:1. Raman spectroscopy and X-ray diffraction were also employed to analyze the precipitates, confirming that U3+ was precipitated and oxidized into UO2, while the trivalent lanthanide ions formed oxychlorides (LnOCl). As a preliminary study of actinide co-precipitation, we also electrochemically monitored the precipitation reactions in a mixed melt containing uranium and lanthanides, demonstrating a higher reactivity of the former with the oxide ion in LiCl-KCl. [ABSTRACT FROM AUTHOR]

The work exploring the stoichiometry of Pt deposition via surface-limited redox replacement of the underpotentially deposited (UPD) Cu monolayer on Au(111) is presented. The Cu UPD monolayer is formed from 10-3 M Cu2+ + 0.1 M HClO4 solution, whereas the Pt deposition via surface-limited redox replacement reaction is carried out in 10-3 M {PtCl6}2- + 0.1 M HClO4 solution at open-circuit potential. Our results indicate that the Pt submonolayers have two-dimensional morphology and linear dependence of their coverage on the amount (coverage) of the replaced Cu UPD monolayers. Our analysis shows that the oxidation state of Cu during redox replacement reaction is 1+, suggesting that four Cu UPD adatoms are replaced by each deposited Pt adatom. This work stresses the general importance of the anions, determining the stoichiometry of metal deposition reaction via surface-limited redox replacement of the UPD monolayers. [ABSTRACT FROM AUTHOR]

Incorporation of sulfur into 2.4 T CoFe alloys during galvanostatic deposition has been studied. The results indicate that the main source of sulfur in magnetic deposit is saccharin used as an additive in the plating solution. The atomic percent of sulfur in deposit and the sulfur incorporation rate show strong dependence on saccharin concentration in the plating solution. This dependence has pronounced maximum at Csac ≈0.12 g L-1, while for Csac ≥ 1.5 g L-1 the incorporation rate approaches constant value. A simple physical model is developed to describe the sulfur incorporation as a function of saccharin concentration having an excellent qualitative agreement with experimental data. The corrosion and magnetic properties of the electrodeposited 2.4 1 CoFe alloys were found to be the strong function of the sulfur incorporation rate, and these results are discussed within the framework of the proposed sulfur incorporation model. [ABSTRACT FROM AUTHOR]