A hybrid photoelectrochemical cell that oxidizes biomaterials and reduces protons to hydrogen has been developed. Upon excitation of a porphyrin sensitized, Grätzel-type anode electrons are injected into the TiO2 CB, which results in cathodic evolution of hydrogen and formation of the porphyrin radical cation. Electrons to reduce the porphyrin radical cation come from NADH, the coenzyme and substrate-to-electrode mediator which works in conjunction with various dehydrogenase enzymes. Both Pt- and hydrogenase-based catalysts are used to produce hydrogen at the cathode. The design, synthesis, and photoelectrochemical characterization of models for the donor side of PSII will also be presented. These consist of a porphyrin-based model of P680 covalently linked to phenol, modeling tyrosine, and H-bonded to imidazole, modeling histidine. This construct models the TYR/HIS mediator coupling P680 to the water oxidizing unit in PSII. Initial experiments with these compounds as sensitizers for the photoanode will be described.