The sustainable production of chemicals and fuels from abundant solar energy and renewable carbon sources provides a promising route to reduce climate-changing CO₂ emissions and our dependence on fossil resources. Here, we demonstrate solar-powered formate production from readily available biomass wastes and CO₂ feedstocks via photoelectrochemistry. Non-precious NiOOH/α-Fe₂O₃ and Bi/GaN/Si wafer were used as photoanode and photocathode, respectively. Concurrent photoanodic biomass oxidation and photocathodic CO₂ reduction towards formate with high Faradaic efficiencies over 85% were achieved at both photoelectrodes. The integrated biomass-CO₂ photoelectrolysis system reduces the cell voltage by 32% due to the thermodynamically favorable biomass oxidation over conventional water oxidation. Moreover, we show solar-driven formate production with a record-high yield of 23.3 μmol cm⁻² h⁻¹ as well as high robustness using the hybrid photoelectrode system. The present work opens opportunities for sustainable chemical and fuel production using abundant and renewable resources on earth—sunlight, biomass and CO₂.

利用丰富的太阳能和可再生碳源可持续生产化学品和燃料，为减少气候变化的 CO ₂排放和我们对化石资源的依赖提供了一条有前途的途径。在这里，我们展示了通过光电化学利用现成的生物质废物和 CO ₂原料进行太阳能甲酸盐生产。非贵金属NiOOH/α-Fe ₂ O ₃和Bi/GaN/Si晶片分别用作光电阳极和光电阴极。在两个光电极上都实现了同时进行光阳极生物质氧化和光阴极 CO ₂还原生成甲酸盐，法拉第效率超过 85%。综合生物质-CO ₂由于热力学上比传统水氧化更有利的生物质氧化，光电系统将电池电压降低了 32%。此外，我们展示了太阳能驱动的甲酸盐生产，其产率为创纪录的 23.3 μmol cm ^-2 h ^-1，并且使用混合光电极系统具有高稳健性。目前的工作为使用地球上丰富的可再生资源（阳光、生物质和 CO ₂ ）进行可持续化学品和燃料生产提供了机会。