A bias-free photochemical diode, in which a p-type photocathode is connected to an n-type photoanode to harness light for driving photoelectrochemical reduction and oxidation pairs, serves as a platform for realizing light-driven fuel generation from CO₂. However, the conventional design, in which cathodic CO₂ reduction is coupled with the anodic oxygen evolution reaction (OER), requires substantial energy input. Here we present a photochemical diode device that harnesses red light (740 nm) to simultaneously drive biophotocathodic CO₂-to-multicarbon conversion and photoanodic glycerol oxidation as an alternative to the OER to overcome the above thermodynamic limitation. The device consists of an efficient CO₂-fixing microorganism, Sporomusa ovata, interfaced with a silicon nanowire photocathode and a Pt–Au-loaded silicon nanowire photoanode. This photochemical diode operates bias-free under low-intensity (20 mW cm⁻²) red light irradiation with ~80% Faradaic efficiency for both the cathodic and anodic products. This work provides an alternative photosynthetic route to mitigate excessive CO₂ emissions and efficiently generate value-added chemicals from CO₂ and glycerol.

无偏压光化学二极管作为实现光驱动CO ₂燃料生成的平台，其中p型光电阴极连接到n型光电阳极以利用光驱动光电化学还原和氧化对。然而，阴极CO ₂还原与阳极析氧反应(OER)结合的常规设计需要大量的能量输入。在这里，我们提出了一种光化学二极管装置，它利用红光（740 nm）同时驱动生物光阴极CO ₂到多碳的转化和光阳极甘油氧化，作为OER的替代方案，以克服上述热力学限制。该装置由高效的CO ₂固定微生物Sporomusa ovata组成，与硅纳米线光电阴极和负载Pt-Au 的硅纳米线光电阳极连接。该光化学二极管在低强度 (20 mW cm ^{- 2} ) 红光照射下无偏压工作，阴极和阳极产品的法拉第效率均约为 80%。这项工作提供了一种替代的光合作用途径，以减少过度的CO ₂排放并有效地从CO ₂和甘油产生增值化学品。