Light-driven biohybrid system utilizes N(2) for photochemical CO(2) reduction

Attempting to couple photochemical CO(2) reduction with N(2) fixation is usually difficult, because the reaction conditions for these two processes are typically incompatible. Here, we report that a light-driven biohybrid system can utilize abundant, atmospheric N(2) to produce electron donors via biological nitrogen fixation, to achieve effective photochemical CO(2) reduction. This biohybrid system is constructed by incorporating molecular cobalt-based photocatalysts into N(2)-fixing bacteria. It is found that N(2)-fixing bacteria can convert N(2) into reductive organic nitrogen and create a localized anaerobic environment, which allows the incorporated photocatalysts to continuously perform photocatalytic CO(2) reduction under aerobic conditions. Specifically, the light-driven biohybrid system displays a high formic acid production rate of over 1.41 × 10(−14) mol h(−1) cell(−1) under visible light irradiation, and the organic nitrogen content undergoes an over-3-fold increase within 48 hours. This work offers a useful strategy for coupling CO(2) conversion with N(2) fixation under mild and environmentally benign conditions.