Water-splitting catalysis and solar fuel devices: artificial leaves on the move.

The development of new energy materials that can be utilized to make renewable and clean fuels from abundant and easily accessible resources is among the most challenging and demanding tasks in science today. Solar-powered catalytic water-splitting processes can be exploited as a source of electrons and protons to make clean renewable fuels, such as hydrogen, and in the sequestration of CO2 and its conversion into low-carbon energy carriers. Recently, there have been tremendous efforts to build up a stand-alone solar-to-fuel conversion device, the "artificial leaf", using light and water as raw materials. An overview of the recent progress in electrochemical and photo-electrocatalytic water splitting devices is presented, using both molecular water oxidation complexes (WOCs) and nano-structured assemblies to develop an artificial photosynthetic system.