Photoreduction of CO₂ with a Formate Dehydrogenase Driven by Photosystem II Using a Semi-artificial Z-Scheme Architecture.

Abstract

Solar-driven coupling of water oxidation with CO2 reduction sustains life on our planet and is of high priority to contemporary energy research. Here, we report a photoelectrochemical tandem device, which performs photocatalytic CO2 reduction to formate. We employ a semi-artificial design, which wires a W-dependent formate dehydrogenase (FDH) cathode to a photoanode containing the photosynthetic water oxidation enzyme, photosystem II, via a synthetic dye with complementary light absorption. From a biological perspective, the system achieves a metabolically-inaccessible pathway of light-driven CO2 fixation to formate. From a synthetic point of view, it represents a proof-of-principle system utilizing precious-metal-free catalysts for selective CO2 to formate conversion using water as an electron donor. This hybrid platform demonstrates the translatability and versatility of coupling abiotic and biotic components to create challenging models for solar fuel and chemical synthesis.