Aim of the project “Photogenerated Hydrogen by Organic Catalytic Systems (PHOCS)” is the realization of a new-concept,photoelectrochemical system for hydrogen production, based on the hybrid organic/inorganic and organic/liquid interfaces. PHOCS takes the move from the recent demonstration of reduction/oxidation reactions taking place, under visible light and at zero bias, at the interface of an organic semiconductor and an aqueous electrolyte, obtained by the coordinator’s group.PHOCS intends to combine the visible-light absorption properties of organics, together with the enhanced charge transport capabilities of inorganic semiconductors, in order to build a hybrid photoelectrode for hydrogen generation. New organic donor and acceptor materials (conjugated polymers and fullerenes derivatives) will be synthesized, properly tuning HOMO-LUMO levels position and energy gap extent for semi-water splitting purposes. In order to build properly-working photo-electrochemical cells, issues such as stability, wettability, catalytic functionality, electron transfer processes at the polymer/electrolyte interface will also be faced during the synthesis step. Multifunctional, high surface area, inorganic electrodes will be moreover developed, in order to increase surface area, provide ohmic contact to the organic active layer, 3D control of the donor-acceptor junction and advanced light management. Spectro-electrochemical characterization of organic/inorganic and organic/electrolytic solution interfaces will be continuously performed, in order to deep characterize charge transfer phenomena and improve the device performances. Final aim of PHOCS project is the realization of a scaled-up, 10x10 cm2, 1% solar-to-hydrogen energy conversion efficient device, as a tangible first step towards the new “organic water splitting” technology.