Converting solar energy into chemicals and fuels through photoelectrocatalytic (PEC) process is challenging but holds significant potential for advancing sustainable development. Here we introduce an innovative system to realize solar-driven NH₃ production from waste nitrate by nano-structured top layer (NSTL) hybrid catalysts modified commercial Si absorber, to bridge the gap from fundamental understanding to the process engineering. Specifically, we employ a rationally designed Si/Cu-NSTL/Co(OH)₂ ternary photocathode featuring a Schottky barrier contact enabling optimized photo-carrier transport pathways and a beneficial co-adsorption configuration of *NO₃-H₂O moieties. This photocathode exhibits the best-known performance in the literature for the PEC conversion of NO₃ to NH₃, boasting an onset potential of approximately 1 V_RHE and a remarkable Faradaic efficiency of nearly 100%. Building upon these findings, we develop the first large-scale unbiased PEC device (an artificial leaf) capable of simultaneously producing NH₃ and valorizing biomass, achieving a solar utilization efficiency of approximately 4%. Its scalability and practical feasibility have been further validated through rigorous outdoor testing with an assembled tandem device array. The process techno-economic assessment shows compelling economic viability of this technology across diverse application scenarios in NH₃ production, resulting in substantial savings of fossil fuel and a reduction of CO₂ emissions. We anticipate that this work will serve as a valuable resource for the design of next-generation photoelectrodes and devices, bringing us one step closer to realizing standalone solar-to-sustainable chemical applications.

中文翻译：

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纳米结构混合催化剂使人造叶子能够利用太阳能从硝酸盐生产氨


通过光电催化（PEC）过程将太阳能转化为化学品和燃料具有挑战性，但在促进可持续发展方面具有巨大潜力。在这里，我们介绍了一种创新系统，通过纳米结构顶层 (NSTL) 混合催化剂和改性商用硅吸收剂，实现从废硝酸盐中太阳能驱动的 NH ₃ 生产，从而弥合从基础理解到工艺工程的差距。具体来说，我们采用合理设计的 Si/Cu-NSTL/Co(OH) ₂ 三元光电阴极，具有肖特基势垒接触，可实现优化的光载流子传输路径和*NO ₃ -H ₂ O 部分。该光电阴极在将 NO ₃ 转化为 NH ₃ 的 PEC 转化方面表现出了文献中最知名的性能，起始电位约为 1 V _RHE 法拉第效率接近 100%，令人惊叹。基于这些发现，我们开发了第一个大型无偏 PEC 装置（人造叶子），能够同时生产 NH ₃ 和生物量，实现约 4% 的太阳能利用效率。通过组装串联器件阵列的严格户外测试，其可扩展性和实际可行性得到了进一步验证。工艺技术经济评估表明，该技术在 NH ₃ 生产的不同应用场景中具有令人信服的经济可行性，可大幅节省化石燃料并减少 CO ₂ 排放。 我们预计这项工作将成为下一代光电极和设备设计的宝贵资源，使我们离实现独立的太阳能到可持续化学应用又近了一步。