Abstract
Water oxidation is the key reaction in natural and artificial photosyntheses but is kinetically and thermodynamically sluggish. Extensive efforts have been made to develop artificial systems comparable to the natural system. However, constructing a molecular system based on ubiquitous metal ions with high performance in aqueous media similar to a natural system, remains challenging. In this study, inspired by nature, we successfully achieve highly efficient water oxidation in aqueous media. By electrochemical polymerisation of a pentanuclear iron complex bearing carbazole moieties, we successfully integrate two essential features of the natural system: catalytic centre composed of ubiquitous metal ions and charge transporting site. The resulting material catalyses water oxidation with a Faradaic efficiency of up to 99% in aqueous media. Our results provide a strategy to develop catalytic systems for water oxidation.