KCS

The successful utilization of the clean energy carrier hydrogen (H₂) as a fuel requires methods for H₂ production using primary energy sources not based on fossil fuels. Of possible primary energy sources, solar offers the greatest long-term impact because of its abundance and availability. Our team is engineering bio-inspired nanoscale assemblies to capture visible light and transfer photogenerated electrons to a catalyst at which proton reduction occurs to yield H₂ (Fig. 1). The assemblies make use of a membrane support for orientation and compartmentalization of the components. The target assembly possesses a modular design with three components: (1) zinc-substituted heme proteins (cytochromes) and porphyrin-peptide conjugates that yield reducing electrons upon illumination, (2) a carbon nanotube membrane for rapid charge separation, and (3) bioinspired proton-reducing catalysts based on earth-abundant metals. The presentation will focus on the development of novel biosynthetic methods for the preparation of porphyrin-peptide conjugates and the use of these biomolecules for photoinduced electron transfer to nanotubes and for catalytic hydrogen generation.