Enhanced photocatalytic CO2 reduction on biomineralized CdS via an electron conduit in bacteria

Abstract

There is an increasing trend in semi-artificial photosynthesis systems that combine living cells with inorganic semiconductors to activate a bacterial catalytic network. However, these systems face various challenges, including electron–hole recombination, photocorrosion, and the generation of photoexcited radicals by semiconductors, all of which impair the efficiency, stability, and sustainability of biohybrids. We first focus on a reverse strategy to improve highly efficient CO₂ photoreduction on biosynthesized inorganic semiconductors using an electron conduit in the electroactive bacterium S. oneidensis MR-1. Due to the suppressed charge recombination and photocorrosion on CdS, the maximum photocatalytic production rate of formate in water was 2650 μmol g⁻¹ h⁻¹ (with a selectivity of ca.100%), which ranks high among all photocatalysts and is the highest for inorganic–biological hybrid systems in an all-inorganic aqueous environment. The reverse enhancement effect of electrogenic bacteria on photocatalysis on semiconductors inspires new insight to develop a new generation of bio-semiconductor catalysts for solar chemical production.