NpO+2与UO2+2阳阳离子络合对Np(Ⅵ)/Np(Ⅴ)表观电位及可逆性的影响

NpO⁺₂与UO²⁺₂阳阳离子络合对Np(Ⅵ)/Np(Ⅴ)表观电位及可逆性的影响

摘要: 通过分光光度法考察了阳阳离子络合物的形成，并研究了不同酸度和不同U(Ⅵ)浓度对Np(Ⅵ)/Np(Ⅴ)表观电位及其可逆性的影响。结果表明：溶液中U(Ⅵ)的存在会影响Np(Ⅵ)/Np(Ⅴ)的表观电位；随着U浓度的不断升高，Np(Ⅵ)/Np(Ⅴ)表观电位不断升高，同时该氧化还原反应的可逆性逐渐变差；随着溶液中酸度的提高，Np(Ⅵ)/Np(Ⅴ)表观电位不断降低。

Abstract: The formation of cation-cation complex between Np(Ⅴ) and U(Ⅵ) in the aqueous solution of nitric acid has been studied by spectrophotometry. The influence of U(Ⅵ) concentration on the redox potential of Np(Ⅵ)/Np(Ⅴ) couple in nitric acid media has been also researched. The results show that the presence of U(Ⅵ) influences the redox potential of Np(Ⅵ)/Np(Ⅴ) couple. With an increase in the U(Ⅵ) concentration, the redox potential of Np(Ⅵ)/Np(Ⅴ) is increased and the redox reaction becomes irreversible. It is also found that the redox potential can be reduced by increasing the HNO₃ concentration.