Environmental concerns demand efficient removal of CO₂, a major greenhouse gas. For this purpose, a traditional chemical strategy implements a catalytic conversion of CO₂ to CO, with H₂O as the sacrificial agent to generate O₂. Herein we report the first self-photocatalytic conversion of CO₂ to generate CO and O₂ in the absence of H₂O, using co-cationic perovskite nanocrystal Cs_0.55FA_0.45PbBr₃. We obtained a record production rate 105 μmol g^–1 h^–1 of CO, which is three times that with CsPbBr₃ as photocatalyst at the gas–solid interface. During photocatalytic reaction, a phase transition occurred with an enlarged crystal size through the effect of Ostwald ripening, for which the CO yield approached 3.1 mmol g^–1 within the reaction period of ∼60 h. During this process, both FA and oleylammonium cations were released to provide the proton source for the CO₂ reduction to proceed and generate hydroxyl species required for oxidation. A self-photocatalysis mechanism involving bound hydroxyls is proposed.

中文翻译：

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在无水条件下使用共阳离子钙钛矿纳米晶体自光催化分解二氧化碳

环境问题要求有效去除主要温室气体 CO ₂。为此，传统的化学策略将 CO ₂催化转化为CO，并以 H ₂ O 作为牺牲剂生成 O ₂。在此，我们报告了在没有 H ₂ O 的情况下使用共阳离子钙钛矿纳米晶体 Cs _0.55 FA _0.45 PbBr _{3将 CO 2}首次自光催化转化为CO 和 O ₂。^{我们获得了 105 μmol g –1} h ^–1 CO的创纪录生产率，是 CsPbBr ₃的三倍作为气固界面的光催化剂。在光催化反应过程中，通过奥斯特瓦尔德熟化的作用发生相变，晶体尺寸增大，在~60 小时的反应时间内， CO 产率接近 3.1 mmol g ^{-1 。}在此过程中，FA 和油基铵阳离子均被释放，为 CO ₂还原提供质子源以进行并产生氧化所需的羟基物质。提出了一种涉及结合羟基的自光催化机制。