The well‐known toxicity of lead‐halide‐perovskite (LHP) nanocrystals limits their commercial applications in photocatalysis. Herein, an in situ controlled growth strategy is reported for lead‐free perovskite nanocrystals (Cs₃Bi₂I₉) on the surface of ultrathin Bi₂WO₆ nanosheets through co‐sharing Bi atoms, to generate a direct Z‐scheme heterojunction of Cs₃Bi₂I₉/Bi₂WO₆. Co‐sharing of the Bi atom can enable intimate contact and strong electron coupling between Cs₃Bi₂I₉ and Bi₂WO₆, which can effectively promote the interfacial charge transfer between Cs₃Bi₂I₉ and Bi₂WO₆ complying with a Z‐scheme pathway. The resulting efficient charge transfer and well‐preserved redox ability of Cs₃Bi₂I₉/Bi₂WO₆ heterojunction endow it with a significant improvement of photocatalytic activity for the conversion of CO₂‐to‐CO integrated with water oxidation, exhibiting a fourfold increase compared with pure Cs₃Bi₂I₉ nanocrystals. This study paves a new avenue for the construction of efficient Z‐scheme heterojunction based on lead‐free halide perovskite, which should stimulate further passion on the development of high performance of lead‐free halide perovskite materials for photocatalytic application.

中文翻译：

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无铅钙钛矿直接Z型异质结Cs3Bi2I9 / Bi2WO6的原位构建，用于高效光催化还原CO2

卤化钙钛矿（LHP）纳米晶体的众所周知的毒性限制了它们在光催化中的商业应用。本文报道了通过共共享Bi原子在超薄Bi ₂ WO ₆纳米片表面上无铅钙钛矿纳米晶体（Cs ₃ Bi ₂ I ₉）的原位控制生长策略，以产生直接的Z型异质结。 Cs ₃ Bi ₂ I ₉ / Bi ₂ WO ₆。Bi原子的共共享可实现Cs ₃ Bi ₂ I ₉和Bi ₂ WO之间的紧密接触和强电子耦合₆，可以有效地促进Cs ₃ Bi ₂ I ₉和Bi ₂ WO ₆之间的界面电荷转移，遵循Z方案途径。Cs ₃ Bi ₂ I ₉ / Bi ₂ WO ₆异质结的有效电荷转移和良好保存的氧化还原能力赋予了其显着提高的光催化活性，可将与水氧化结合的CO ₂转化为CO ，显示出与纯Cs ₃ Bi ₂ I ₉相比增加了四倍纳米晶体。这项研究为基于无铅卤化钙钛矿的高效Z方案异质结的构建开辟了一条新途径，这应该激发人们对开发用于光催化应用的高性能无铅卤化钙钛矿材料的进一步热情。