Visible‐Light‐Driven Water Oxidation on a Photoanode by Supramolecular Assembly of Photosensitizer and Catalyst

A ruthenium water oxidation catalyst (WOC) bearing hydrophobic ligands was incorporated on the surface of a dye‐sensitized nanostructured TiO 2 film by formation of a host–guest adduct with the dye. This provides a new strategy for constructing photocatalytically active electrodes for water oxidation. The resultant photoanode exhibits a photocurrent of 800 μA cm −2 under visible‐light illumination (λ>400 nm, 300 mW cm −2 ) and 240 μA cm −2 under simulated sunlight illumination (AM 1.5G, 100 mW cm −2 ) with an applied bias of 0.2 V vs. NHE in neutral phosphate buffer.