Аннотация:Abstract Two photoanodes based on a binuclear ( 2 ) and a mononuclear ruthenium ( 3 ) water oxidation catalysts were assembled in combination with a molecular photosensitizer ( 1 ) by using a co‐adsorption method. The anodes were used in dye‐sensitized photoelectrochemical cells (DS‐PECs) for visible‐light‐driven water splitting. A DS‐PEC device using TiO 2 ( 1 + 2 ) as working electrode (WE) exhibits better performance than TiO 2 ( 1 + 3 ) as WE in light‐driven water splitting. Detailed photoelectrochemical studies on these DS‐PEC devices are discussed.