The synthesis of solar fuels (H2 from water and isopropanol from CO2) in a novel photoelectrocatalytic (PEC) device, and the development of the related photo- and electro-catalysts, is discussed. The PEC reactor can be considered the integration between a photo-electrochem. app. (which operate in soln. with a different type of electrodes) and a PEM fuel cell (which has a similar engineering, but in which is not present the photocatalyst). This device allows the phys. sepn. of the two reactions of water oxidn. and CO2 redn. or H2 formation, in a photoanode and electrocathode resp., in order to increase the efficiency of the two reactions and limit charge recombination. This device could be also used to produce renewable H2 by photocatalytic reforming of chems. present in waste stream from agro-food or agro-chem. prodn., such as dild. streams of ethanol, glycerol, etc. [on SciFinder(R)]