Dual Atoms Anchoring at Microbe–Semiconductor Interfaces Boost Charge Transfer for Efficient Biohydrogen Production

ABSTRACT Photosynthetic biohybrid systems, which integrate the superior light absorption efficiency of semiconductors with the specific biocatalytic pathways of microorganisms, have emerged as a sustainable platform to produce chemicals. However, due to complex interfacial contact and unfavorable charge transfer, it remains challenging to optimize extracellular electron transfer pathways and achieve efficient solar‐driven biocatalysis. Herein, we report a strategy of anchoring dual atoms at the microbe–semiconductor interfaces to promote interfacial electron transfer and enhance solar‐to‐chemical conversion. Specifically, the C ₃ N ₄ /CuCo photocatalyst is coupled with the electroactive bacterium S. oneidensis MR‐1 to form a biohybrid system. The dual atoms of Cu and Co at the interfaces facilitate electron and hole separation, thereby boosting indirect and direct electron transfer compared to non‐modified C ₃ N ₄ – S. oneidensis MR‐1 biohybrids. Moreover, operando single‐cell photocurrent analysis further unravels a 4.93‐fold increase in electron uptake for C ₃ N ₄ /CuCo– S. oneidensis MR‐1 over C ₃ N ₄ – S. oneidensis MR‐1. In contrast to S. oneidensis MR‐1, the biohybrid system exhibits a remarkable 34.01‐fold enhancement in H ₂ evolution together with a quantum yield of 6.73% at 450 nm. Overall, this work highlights dual‐atomic interface engineering as a synergistic strategy to accelerate electron transfer across microbe‐semiconductor boundaries and realize efficient solar‐to‐fuel conversion in noble‐metal‐free systems.