Photoelectrochemical splitting of water into hydrogen is a potential route to motivate the application of solar-driven conversion to clean energy but is regularly limited by its low efficiency. The key to addressing this issue is to design a suitable photocathode configuration for high-efficiency photogenerated carrier separation and transmission to photocathode-surface reaction sites. In this work, we report a Si-Cu₂O tandem photocathode featuring a p-n-p configuration for solar-driven hydrogen evolution in an alkaline solution. Driven by this built-in field, the electrons induced from Si were transferred through FeOOH, which acted as electron tunnels, to combine with the holes from Cu₂O, triggering more electrons generated from Cu₂O to particiate in the surface reaction. Under simulated sunlight, the optimized photocathode achieved and maintained a photocurrent density of −11 mA/cm² at 0 V_RHE in alkaline conditions for 120 min, outperforming the reported tandem cell consisting of Si and Cu₂O photocathodes. Our results provide valuable insight into a feasible way to construct an optimized photocathode for efficient solar-driven H₂ evolution.

中文翻译：

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基于氧化亚铜/硅串联光电阴极的 pnp 配置，用于加速太阳能驱动的析氢

将水光电化学分解为氢气是推动太阳能驱动的清洁能源转换应用的潜在途径，但通常因其低效率而受到限制。解决这个问题的关键是设计合适的光电阴极配置，以实现高效的光生载流子分离和传输到光电阴极表面反应位点。在这项工作中，我们报道了一种 Si-Cu ₂ O 串联光电阴极，具有 pnp 配置，用于在碱性溶液中太阳能驱动的析氢。在这个内置场的驱动下，Si感应的电子通过充当电子隧道的FeOOH转移，与Cu ₂ O的空穴结合，触发Cu ₂ O产生更多的电子参与表面反应。在模拟阳光下，优化的光电阴极在0 V _{RHE 、碱性条件下120分钟内实现并保持-11 mA/cm} ²的光电流密度，优于报道的由Si和Cu ₂ O光电阴极组成的串联电池。我们的研究结果为构建优化光电阴极以实现高效太阳能驱动的 H ₂演化的可行方法提供了宝贵的见解。