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 TiO 2 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.