电活性铁氰化镍膜电极对稀土钇的电控离子分离

通过电沉积方法分别在镀铂石英晶片和铂基底上制备了电活性铁氰化镍膜，并考察了膜电极在含钇离子溶液中的电控离子交换性能. 在0.1 mol·L^-1的硝酸钇溶液中，使用循环伏安法及石英晶体微天平技术测试考察了铁氰化镍膜对钇离子的置入释放性能及对应的质量变化，同时比较了铁氰化镍膜电极在Y(NO₃)₃和Sr(NO₃)₂溶液中的电化学性能. 在0.1 mol·L^-1 Y(NO₃)₃ + Sr(NO₃)₂]混合溶液中，通过循环伏安法分析了薄膜对Y³⁺/Sr²⁺离子的选择性. 用扫描电子显微镜观察了铁氰化镍膜的表面形貌，并通过X射线光电子能谱仪测定了膜在氧化和还原状态下的元素组成. 结果表明，铁氰化镍膜在含Y³⁺溶液中具有良好的离子交换行为，其中氧化过程薄膜质量减少，对应着钇离子的释放；还原过程薄膜质量增加，对应钇离子的置入；在0.0 V或0.9 V调控膜电极的氧化还原状态实现对钇离子的有效分离.

Electrochemically Switched Separation of Yttrium Ion Using Electroactive Nickel Hexacyanoferrate Thin Films in Rare Earth Metal Solution

Electroactive nickel hexacyanoferrate (NiHCF) thin films were synthesized by cathodic deposition and investigated as electrochemically switched ion exchange (ESIX) materials for the separation of Y³⁺ from aqueous solutions. In 0.1 mol·L^-1 Y(NO₃)₃ solution, cyclic voltammetry (CV) combined with electrochemical quartz crystal microbalance (EQCM) technique was used to investigate the electroactivity, reversibility of the film electrodes and the mechanism of ion exchange. The electrochemical behavior of NiHCF film electrodes was also compared with that in Sr(NO₃)₂ solutions. The ion selectivity of the film was investigated in 0.1 mol·L^-1 solutions containing Y(NO₃)₃ + Sr(NO₃)₂]. The elementary composition of NiHCF films in reduced and oxidized forms were also characterized by X-ray photoelectron spectroscopy (XPS). Experimental results show that the electroactive NiHCF films have reversible electrochemical behavior in aqueous solutions containing Y³⁺ and Sr²⁺, respectively. The NiHCF film electrodes displayed a high Y³⁺ selectivity in Y³⁺/Sr²⁺ binary mixtures and the Y³⁺ ions could be separated effectively from aqueous solutions by ESIX processes.