Microbial electro- and photo-electrochemical CO₂ fixation, in which CO₂-reducing microorganisms are directly interfaced with a cathode material, represent promising approaches for sustainable fuel production. Although considerable efforts have been invested to optimize microorganism species and electrode materials, the microorganism-cathode interface has not been systematically studied. Here, investigation of the interface allowed us to optimize the CO₂-reducing rate of silicon nanowire/Sporomusa ovata system. Tuning the bulk electrolyte pH and increasing its buffering capacity supported the formation of a close-packed nanowire-bacteria cathode. Consequently, the resulting close-packed biohybrid achieved a CO₂-reducing current density of ∼0.65 mA cm⁻². When coupled with a photovoltaic device, our system enabled solar-to-acetate production with ∼3.6% efficiency over 7 days.

微生物电化学和光电化学CO ₂固定（其中还原CO _2的微生物直接与阴极材料接触）代表了可持续燃料生产的有前途的方法。尽管已投入大量精力来优化微生物种类和电极材料，但尚未系统地研究微生物-阴极界面。在这里，对界面的研究使我们能够优化硅纳米线/卵形孢子体系统的CO ₂降低率。调节整体电解质的pH值并增加其缓冲能力有助于形成密堆积的纳米线-细菌阴极。因此，所产生的紧密包装的生物杂化物获得了CO _2。降低的电流密度约为0.65 mA cm ^-2。当与光伏设备结合使用时，我们的系统可以在7天内以约3.6％的效率生产太阳能醋酸盐。