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.