Water splitting is the general term for a chemical reaction in which water is converted into oxygen and hydrogen. Water splitting is actively researched because demand for cheap hydrogen is expected to rise with the new hydrogen economy.
thermolysis on defective carbon substrates, thus making hydrogen production possible at temperatures just under 1000°C 
Water splitting also donates electrons to power the electron transport chain in photophosphorylation of photosynthesis. Various techniques for water splitting have been issued water splitting patents  in the United States.
^ Strategies for the Development of Visible-light-driven Photocatalysts for Water Splitting Akihiko Kudo, Hideki Kato1 and Issei Tsuji Chemistry Letters Vol. 33 (2004) , No. 12 p.1534
^ Kostov, M. K.; Santiso, E. E.; George, A. M.; Gubbins, K. E.; and Nardelli, M. Buongiorno (2005). "Dissociation of Water on Defective Carbon Substrates" (PDF). Physical Review Letters. Retrieved on 2007-11-05.