Organic–inorganic hybrid perovskites (OIHPs) like methylammonium lead iodide perovskite (MAPbI₃) are attractive candidates for solar hydrogen production. However, the serious charge recombination occurring on OIHPs seriously impairs their photocatalytic performance, defining the imperative to develop efficient strategies that can address this issue. Herein, we show that by introducing a dynamic Cu/(CuI₂)⁻ couple as the electron/energy relay station, drastically improved extraction of photogenerated electrons from MAPbI₃ can be achieved, thus leading to significantly depressed charge recombination and enhanced photocatalytic hydrogen production. We found that the electrons generated from MAPbI₃ can be efficiently captured by the (CuI₂)⁻ ions in the reaction solution to produce metallic Cu as the electron/energy storage medium, thereby retarding the recombination of photogenerated charges and realizing the simultaneous storage of photon energy. Subsequently, the in situ generated metallic Cu reacts with HI to release the as-stored solar energy, realizing decoupled off-light hydrogen generation that resembles the dark reduction reaction in natural photosynthesis. Moreover, metallic Cu can also act as a hydrogen evolution reaction (HER) co-catalyst to promote the proton reduction reaction with photogenerated electrons from MAPbI₃. By further introducing Pt as the HER co-catalyst, additional drastic enhancement in both the dark HER and light-driven proton reduction reaction can be realized. Consequently, the photocatalytic hydrogen evolution activity of MAPbI₃ is enhanced by ca. 2334 times through the cascade interplay of the Cu/(CuI₂)⁻ couple and Pt co-catalyst, achieving an outstanding solar-to-hydrogen (STH) energy conversion efficiency of ca. 5.25%.

中文翻译：

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通过引入动态电子/能量中继耦合来抑制杂化钙钛矿中的电荷复合，以增强光催化制氢


有机-无机杂化钙钛矿 （OIHP），如甲基铵碘化铅钙钛矿 （MAPbI₃），是太阳能制氢的有吸引力的候选者。然而，OIHP 上发生的严重电荷复合严重损害了它们的光催化性能，因此必须开发能够解决这个问题的有效策略。在此，我们表明，通过引入动态 Cu/（CuI₂）⁻ 对作为电子/能量中继站，可以大大改善从 MAPbI₃ 中提取光生电子，从而导致显着抑制电荷复合并增强光催化制氢。我们发现 MAPbI₃ 产生的电子可以被反应液中的 （CuI₂）⁻ 离子有效地捕获，产生金属 Cu 作为电子/储能介质，从而延缓光生电荷的复合并实现光子能量的同步存储。随后，原位生成的金属 Cu 与 HI 反应释放出储存的太阳能，实现解耦的离光氢生成，类似于自然光合作用中的暗还原反应。此外，金属 Cu 还可以作为析氢反应 （HER） 助催化剂，促进与 MAPbI₃ 的光生电子发生质子还原反应。通过进一步引入 Pt 作为 HER 助催化剂，可以实现暗 HER 和光驱动质子还原反应的额外剧烈增强。 因此，通过 Cu/（CuI₂）⁻ 对和 Pt 助催化剂的级联相互作用，MAPbI₃ 的光催化析氢活性提高了约 2334 倍，实现了约 5.25% 的出色太阳能制氢 （STH） 能量转换效率。