Ruthenium Dioxide Electrodes as Suitable Anodes for Water Photolysis

This paper presents a cell system in which a photoinduced redox reaction occurs in the cathodic compartment which is coupled to a RuO 2 ‐anode. The light induced oxidation of the ruthenium complex Ru (bipy) by peroxodisulfate is used to illustrate that even under diffuse room light irradiation the photopotentials developed at the Pt‐cathode are sufficient to afford water oxidation in the anode compartment. The oxygen produced at the RuO 2 ‐electrode stands in a stochiometric relation to the current passed through the circuit. Implications for a cell system in which H 2 and O 2 are produced in separate compartments under illumination are discussed.