Cyclic Water Cleavage by Visible Light: Drastic Improvement of Yield of H2 and O2 with Bifunctional Redox Catalysts


  • This work was supported by the Swiss National Foundation for Scientific Research as well as Ciba-Geigy and Engelhard Industries Corporation.


A further step on the road to utilization of solar energy by cleavage of water is made possible by a new catalyst which promotes both H2-and O2-formation in the (known) Ru(bpy)math image/methylviologen system. The catalyst consists of RuO2 (0.1%) in (Nb-doped) n-TiO2 charged with finely divided Pt. The rate of generation of H2 remains constant even after irradiation for 4 d with visible light.