Artificial photosynthetic assemblies constructed by the self-assembly of synthetic building blocks for enhanced photocatalytic hydrogen evolution

Abstract

An artificial photosynthetic assembly (APA) of a hollow-rod structure was successfully constructed by using synthetic building blocks to mimic the structure and function of natural photosynthetic bacteria. The APA was formed by the incorporation of carbon nanoparticles as light harvesters into an enzyme-like polymer, PEI-Co, containing cobalt complexes as redox catalytic centres. The APA features a bacteria-like shape of ca. 2–3 μm length rods and a hollow structure positioning photosynthetic components at the surface. The APA integrates key components, the light harvester, redox catalyst, and proton relay group, of photosynthetic systems in assemblies formed from a polymeric framework. The APA system in aqueous solution converts protons to H₂ under visible light irradiation with obvious advantages. It exhibits a 50-fold improvement in hydrogen production activity and has a broader pH response of photocatalytic H₂ production compared with a non-assembled system.