Oxidation State Changes and Structure of Electrochromic Iridium Oxide Films

摘要: Oxidation state changes, completeness of oxidation, and densities anodically formed, electrochromic iridium oxide films have been determined by combined gravimetric, coulometric, reflection spectroscopy analyses. The results show that the oxidation Ir ions in is changed from III to IV during anodic coloration process [0.25 1.25V (RHE)], rather than II as previously postulated, virtually all film are accessible for electrochemical reduction. mean density 2.0g cm−3, compared 11.68 bulk crystalline . structure was shown electron microscopy consist grains 0.05–0.1 μm diameter, surrounded voids. In addition, presence a high microvoids ~25A diameter detected. highly porous permits ready access electrolyte throughout entire facilitates rapid bleaching (~40 msec) observed aqueous electrolytes. apparent accessibility also implies transport, within grains, mobile charge‐compensating which must be injected ejected preserve electroneutrality. Mechanisms ion transport discussed.