Formation of FeIV and NiIV by Electrochemical and Chemical Oxidation of an Iron‐Substituted Nickel( II ) Hydroxide: The Direct Two‐Electron Step NiII → NiIV + 2e−

Six NiIV ions make up the coordination environment of each FeIV ion in the γ‐NiOOH‐like layer of the (electrochemically) oxidized form of the iron‐substituted nickel(II) hydroxide 1, as can be deduced from Mössbauer spectroscopic and electrochemical investigations. No NiIII ions are present in the redox‐active material. The direct two‐electron step NiII → NiIV + 2e− must be assumed. equation image