Abstract

Atomically precise gold (Au) nanoclusters (NCs) as visible light photosensitizers supported on the substrate for photoredox catalysis have attracted considerable attentions. However, efficient control of their photocatalytic activity and long-term stability is still challenging. Herein, we report a coordination-assisted self-assembly strategy in combination with electrostatic interaction to sandwich Au₂₅(Capt)₁₈ (abbreviated as Au₂₅, Capt = captopril) NCs between an inner core and an outer shell made of UiO-66, denoted as UiO-66@Au₂₅@UiO-66. Notably, the sandwich-like nanocomposite displays significantly enhanced catalytic activity along with an excellent stability when used in the selective photocatalytic aerobic oxidation of sulfide to sulfoxide. As comparison, Au₂₅ NCs simply located at the outer surface or insider matrix of UiO-66 (short as Au₂₅/UiO-66 and Au₂₅@UiO-66) show poor stability and low conversion, respectively. This structure regulated difference in the catalytic performances of three nanocomposites is assigned to the varied distribution of active sites (Au NCs) in metal-organic frameworks (MOFs). This work offers the opportunity for application of nanoclusters in catalysis, energy conversion and even biology.

中文翻译：

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金纳米簇-MOF纳米复合材料的结构调控催化性能

摘要

原子精确的金（Au）纳米团簇（NC）作为可见光光敏剂，负载在用于光氧化还原催化的基质上，引起了广泛的关注。然而，对其光催化活性和长期稳定性的有效控制仍然具有挑战性。在此，我们报告了一种协同辅助的自组装策略，该方法结合了静电相互作用，在由UiO-66制成的内芯和外壳之间夹入Au ₂₅（Capt）₁₈（缩写为Au ₂₅，Capt = captopril）NC NCs，表示为UiO-66 @ Au ₂₅@ UiO-66。值得注意的是，当用于硫化物到亚砜的选择性光催化需氧氧化中时，三明治状纳米复合材料显示出显着增强的催化活性以及优异的稳定性。相比之下，仅位于UiO-66的外表面或内部矩阵（简称Au ₂₅ / UiO-66和Au ₂₅ @ UiO-66）的Au ₂₅ NC分别显示出较差的稳定性和较低的转化率。三种纳米复合材料催化性能的这种结构调节差异被赋予了金属有机骨架（MOF）中活性位点（Au NCs）的变化分布。这项工作提供了将纳米团簇应用于催化，能量转化甚至生物学的机会。