Efficient water oxidation via intramolecular O–O bond formation by the coupling of vicinal hydroxo ligands on dinuclear ruthenium complexes immobilized on electrode surfaces

Abstract Artificial photosynthesis has attracted great attention as a viable way of converting and storing solar energy into chemical fuels. One of the primary challenges in developing an efficient artificial photosynthetic system is to facilitate sluggish kinetics of water oxidation. Molecular water oxidation catalysts (WOCs) that are based on transition metals offer the advantages of catalytic activity tuning by a rational ligand design and mechanistic investigations on the catalytic mechanism through experimental and theoretical studies. This highlight review presents the recent progress that our group has made on water oxidation catalysis by using a dinuclear ruthenium complex in solution and on electrode surfaces. The mechanism of intramolecular O–O bond formation by the coupling of vicinal hydroxo ligands on the dinuclear ruthenium complex is described and its immobilization on electrode surfaces to fabricate efficient molecular anodes for water oxidation is illustrated.