低温熔盐中电沉积制备La-Mg-Ni三元合金膜及其性能研究

Electrodeposition of La-Mg-Ni Alloy Film in Low Temperature Melted Salt and Its Performance

采用恒电位法在乙酰胺-尿素-NaBr-KBr熔体中电沉积出La-Mg-Ni三元合金膜。用扫描电镜(SEM)、X射线衍射(XRD)等方法研究了沉积层的表面形貌和结构,用Tafel极化曲线和交流阻抗(EIS)方法研究了合金薄膜的电化学性能。结果表明,随着阴极电位负移的增大,表面更平整,储氢性能更好。当沉积电位为-1.0V时,沉积层表面的表观活化自由能最小(△G≠=22.35kJ.mol-1),说明具有很高的析氢活性。在EIS中的吸附程度Q为7.98μF.cm-2,表明具有很高的储氢能力。

The La-Mg-Ni alloy films were prepared by a constant-voltage electrodeposition method in acetamide-urea-NaBr-KBr.The surface morphology and structure of the films were studied by SEM and XRD.The electrochemical performance was studied by Tafel and EIS.The results show that the film has smoother surface and better hydrogen storage function with the cathode potential shifting to negative direction.△G≠ and Q of the deposition layer are determined to be 22.35 kJ.mol-1 and 7.98 μF/cm2,respectively when the voltage is-1.0 V,indicating the high hydrogen evolution activity and high hydrogen capacity.