Semiconductor-based photocatalysis has evolved over the past decade into a prevalent approach for alcohol oxidation to afford the corresponding carbonyl compounds or C–C/C–O coupled products. Nonetheless, photocatalytic oxidative lactonization of diols to lactones still significantly lags behind, even though lactones represent a class of ring moieties with excellent biological activities. In this work, we present the high-performance visible-light-mediated lactonization of diols to lactones and H₂ over the Ti₃C₂T_x MXene-supported CdS quantum dots (QDs) with Ni decoration (Ni/CdS/Ti₃C₂T_x). Ti₃C₂T_x acts as a two-dimensional platform for immobilizing CdS to promote the separation and migration of charge carriers, while concomitantly the Cd²⁺ confinement effect of Ti₃C₂T_x significantly retards the hole-induced photocorrosion of CdS. The unique modifications of atomically dispersed Ni species are either incorporated as Ni clusters in CdS to accelerate H₂ evolution, or anchored as a Ni single atom on Ti₃C₂T_x for the efficient adsorption and cyclization of diols. The optimized Ni/CdS/Ti₃C₂T_x exhibits remarkably enhanced activity for lactone synthesis, which is 80.4 times higher than that of blank CdS, along with excellent selectivity and high durability. This work brings a conceptual idea to overcome the well-known intrinsic drawback of photoinduced decomposition in semiconductor-based photocatalysts and offers a generic and robust strategy of utilizing atomically dispersed cocatalyst as active sites for efficient and robust photoredox lactones synthesis and H₂ evolution.

中文翻译：

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Ni 单原子/簇和 MXene 的界面协同作用，实现基于半导体量子点的卓越光氧化还原催化


在过去十年中，基于半导体的光催化已发展成为一种流行的醇氧化方法，以提供相应的羰基化合物或 C-C/C-O 耦合产物。尽管如此，二醇的光催化氧化内酯化到内酯仍然明显滞后，尽管内酯代表了一类具有优异生物活性的环部分。在这项工作中，我们提出了在具有 Ni 装饰 （Ni/CdS/Ti₃C₂T_x） 的 Ti₃C₂T_x MXene 支持的 CdS 量子点 （QD） 上，二醇高性能内酯化为内酯和 H₂。Ti₃C₂T_x 充当固定 CdS 的二维平台，以促进载流子的分离和迁移，同时 Ti₃C₂T_x 的 Cd²⁺ 限制效应显着延缓了 CdS 的空穴诱导光腐蚀。原子分散的 Ni 物质的独特修饰要么作为 Ni 簇掺入 CdS 中以加速 H₂ 的析出，要么作为 Ni 单原子锚定在 Ti₃C₂T_x 上，以实现二醇的高效吸附和环化。优化的 Ni/CdS/Ti₃C₂T_x 表现出显著增强的内酯合成活性，比空白 CdS 高 80.4 倍，同时具有出色的选择性和高耐用性。 这项工作提出了一个概念性想法，以克服基于半导体的光催化剂中众所周知的光诱导分解的固有缺点，并提供了一种通用且稳健的策略，即利用原子分散的助催化剂作为活性位点，以实现高效和稳健的光氧化还原内酯合成和 H₂ 析出。