Investigation of Potentiostatic Electrodeposition of Ir in LiCl-KCl Molten Salt

A uniform and even film of Iridium (Ir) layer was prepared by potentiostatic electrodeposition in LiCl-KCl molten salt using IrCl3 as main salt. The morphology and constitutions of Ir film prepared under different conditions were examined using Scanning Electron Microscope (SEM) and Energy Dispersive Spectrometer (EDS) respectively. It was found that the electrodeposition conducted at the potential reduction peak could prepare Ir layer of high quality. A modification of the potential will also generate Ir film, but of lower quality. Temperature of the molten salt also exerts an obvious influence on deposition, the films formed at a lower temperature are thinner, but more micropores would occur on films when the temperature went too high and the molten salt became unstable. The best condition of potentiostatic electrodeposition of Ir in LiCl-KCl molten salt follows: mole ratio of molten salt LiCl:KCl=58:42; molten salt temperature:823K; concentration of IrCl3 0.045 mol/kg; potential of electrodeposition -1V (vs Pt/Pt(Ⅱ)); duration of electrodeposition: 1 h