<i>Shewanella oneidensis</i> MR-1 respires CdSe quantum dots for photocatalytic hydrogen evolution.

Edwards, Emily H; Jelušić, Jana; Kosko, Ryan M; McClelland, Kevin P; Ngarnim, Soraya S; Chiang, Wesley; Lampa-Pastirk, Sanela; Krauss, Todd D et al. · Proc Natl Acad Sci U S A · 2023

basic_science · Level V

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Abstract

Living bio-nano systems for artificial photosynthesis are of growing interest. Typically, these systems use photoinduced charge transfer to provide electrons for microbial metabolic processes, yielding a biosynthetic solar fuel. Here, we demonstrate an entirely different approach to constructing a living bio-nano system, in which electrogenic bacteria respire semiconductor nanoparticles to support nanoparticle photocatalysis. Semiconductor nanocrystals are highly active and robust photocatalysts for hydrogen (H<sub>2</sub>) evolution, but their use is hindered by the oxidative side of the reaction. In this system, <i>Shewanella oneidensis</i> MR-1 provides electrons to a CdSe nanocrystalline photocatalyst, enabling visible light-driven H<sub>2</sub> production. Unlike microbial electrolysis cells, this system requires no external potential. Illuminating this system at 530 nm yields continuous H<sub>2</sub> generation for 168 h, which can be lengthened further by replenishing bacterial nutrients.

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