The characteristics of nanostructured (a) TiO₂ thin films (based on an ordered array of titania nanotubes) and their performances as photoanode in H₂ production by water splitting or photoreforming of ethanol (in liquid or gas phase) and (b) carbon-nanotube based electrodes for the gas-phase reduction of CO₂ to liquid fuels (mainly isopropanol) are discussed together with their application for the design of a novel photoelectrocatalytic approach for the synthesis of solar fuels.