Electro‐assembly of a Chromophore–Catalyst Bilayer for Water Oxidation and Photocatalytic Water Splitting

The use of electropolymerization to prepare electrocatalytically and photocatalytically active electrodes for water oxidation is described. Electropolymerization of the catalyst Ru^II(bda)(4‐vinylpyridine)₂ (bda=2,2′‐bipyridine‐6,6′‐dicarboxylate) on planar electrodes results in films containing semirigid polymer networks. In these films there is a change in the water oxidation mechanism compared to the solution analogue from bimolecular to single‐site. Electro‐assembly construction of a chromophore–catalyst structure on mesoporous, nanoparticle TiO₂ films provides the basis for a dye‐sensitized photoelectrosynthesis cell (DSPEC) for sustained water splitting in a pH 7 phosphate buffer solution. Photogenerated oxygen was measured in real‐time by use of a two‐electrode cell design.