A biohybrid photobioanode mimicking the Z-scheme has been developed by functional integration of photosystem II (PSII) and PbS quantum dots (QDs) within an inverse opal TiO architecture giving rise to a rather negative water oxidation potential of about -0.55 V vs. Ag/AgCl, 1 m KCl at neutral pH. The electrical linkage between both light-sensitive entities has been established through an Os-complex-modified redox polymer (P ), which allows the formation of a multi-step electron-transfer chain under illumination starting with the photo-activated water oxidation at PSII followed by an electron transfer from PSII through P to the photo-excited QDs and finally to the TiO electrode. The photobioanode was coupled to a novel, transparent, inverse-opal ATO cathode modified with an O -reducing bilirubin oxidase for the construction of a H O/O photobioelectrochemical cell reaching a high open-circuit voltage of about 1 V under illumination.