Atomically precise metal nanoclusters (NCs) have recently been unleashed as an emerging sector of metal nanomaterials but suffer from light-induced poor stability, giving rise to the detrimental self-transformation to metal nanocrystals (NYs), losing the photosensitization effect and ultimately retarding their widespread applications in photoredox catalysis. Are the metal NCs definitely superior to metal NYs in heterogeneous photocatalysis in terms of structural merits? To unlock this mystery, herein, we conceptually demonstrate how to rationally manipulate the instability of metal NCs to construct high-efficiency artificial photosystems and unleash how the metal NYs self-transformed from metal NCs influence the charge transfer in photoredox selective organic transformation. To our surprise, the results indicate that the Schottky-type electron-trapping ability of Au NYs surpasses the photosensitization effect of glutathione (GSH)-protected Au clusters [Au25(GSH)18 NCs] in mediating the charge separation and enhancing the photoactivities towards selective photoreduction of aromatic nitro compounds to amino derives and photocatalytic oxidation of aromatic alcohols to aldehydes under visible light irradiation. This work strategically provides new insights into the inherent instability of metal NCs utilized for photocatalysis and reinforce our fundamental understanding on metal NCs-based artificial photosystems for solar energy conversion.

中文翻译：

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克服原子精确金属纳米团簇的不稳定性，促进光氧化还原有机转化


原子精确的金属纳米团簇 （NCs） 作为金属纳米材料的一个新兴领域近年来被释放出来，但光诱导的稳定性差，导致有害的自转化为金属纳米晶体 （NYs），失去光敏效应，最终阻碍了它们在光氧化还原催化中的广泛应用。就结构优点而言，金属 NC 在非均相光催化中是否绝对优于金属 NYs？为了解开这个谜团，在本文中，我们从概念上展示了如何合理地操纵金属 NCs 的不稳定性来构建高效的人工光系统，并揭示金属 NYs 如何从金属 NCs 自我转化影响光氧化还原选择性有机转化中的电荷转移。令我们惊讶的是，结果表明，Au NYs 的肖特基型电子捕获能力超过了谷胱甘肽 （GSH） 保护的 Au 簇 [Au25（GSH）18 NCs] 的光敏作用，介导电荷分离和增强光活性，在可见光照射下芳香族硝基化合物选择性光还原为氨基衍生物和芳香醇光催化氧化为醛。这项工作从战略上为用于光催化的金属 NC 的固有不稳定性提供了新的见解，并加强了我们对基于金属 NC 的人工光系统用于太阳能转换的基本理解。