This disclosure relates to photocatalytic polyoxometalate compositions of tungstovanadates and uses as water oxidation catalysts. In certain embodiments, the disclosure relates to compositions comprising water, a complex of a tetra-metal oxide cluster and VW.sub.9O.sub.34 ligands, and a photosensitizer. Typically, the metal oxide cluster is Co. In certain embodiments, the disclosure relates to electrodes and other devices comprising water oxidation catalysts disclosed herein and uses in generating fuels and electrical power from solar energy.
STATEMENT REGARDING FEDERALLY FUNDED RESEARCH
 This invention was made with government support under grant number DEFG02-03ER15461, awarded by the U.S. Department of Energy. The government has certain rights in the invention.