For practical photoelectrochemical water splitting to become a reality, highly efficient, stable and scalable photoelectrodes are essential. However, meeting these requirements simultaneously is a difficult task, as improvements in one area can often lead to deteriotation in others. Here, addressing this challenge, we report a formamidinium lead triiodide (FAPbI₃) perovskite-based photoanode that is encapsulated by an Ni foil/NiFeOOH electrocatalyst, which demonstrates promising efficiency, stability and scalability. This metal-encapsulated FAPbI₃ photoanode records a photocurrent density of 22.8 mA cm⁻² at 1.23 V_RHE (where V_RHE is voltage with respect to the reversible hydrogen electrode) and shows excellent stability for 3 days under simulated 1-sun illumination. We also construct an all-perovskite-based unassisted photoelectrochemical water splitting system by connecting the photoanode with a same-size FAPbI₃ solar cell in parallel, which records a solar-to-hydrogen efficiency of 9.8%. Finally, we demonstrate the scale-up of these Ni-encapsulated FAPbI₃ photoanodes into mini-modules up to 123 cm² in size, recording a solar-to-hydrogen efficiency of 8.5%.

为了使实用的光电化学水分解成为现实，高效、稳定和可扩展的光电极至关重要。然而，同时满足这些要求是一项艰巨的任务，因为一个领域的改进往往会导致其他领域的恶化。在这里，为了解决这一挑战，我们报告了一种基于钙钛矿的甲脒铅三碘化物（FAPbI ₃）光电阳极，该光电阳极由镍箔/NiFeOOH电催化剂封装，具有良好的效率、稳定性和可扩展性。这种金属封装的FAPbI ₃光阳极在1.23 V _RHE（其中V _{RHE是相对于可逆氢电极的电压）下记录了22.8 mA cm} ^-2的光电流密度，并且在模拟1太阳光照下显示出3天的优异稳定性。_{我们还通过将光阳极与相同尺寸的FAPbI 3}太阳能电池并联，构建了基于全钙钛矿的无辅助光电化学水分解系统，其太阳能制氢效率为9.8%。最后，我们演示了将这些 Ni 封装的 FAPbI ₃光阳极放大为尺寸高达 123 cm ^{2 的}微型模块，记录太阳能制氢效率为 8.5%。