Rational Design of Highly Phosphorescent Nanoclusters for Efficient Photocatalytic Oxidation

Analyzing the molecular structure-photophysical property correlations of metal nanoclusters to accomplish function-oriented photocatalysis could be challenging. Here, the selective heteroatom alloying has been exploited to a Au₁₅ nanocluster, making up a structure-correlated nanocluster series, including homogold Au₁₅, bimetallic Ag_xAu_15-x and Cu_xAu_15-x, trimetallic Ag_xCu_yAu_15-x-y, and tetrametallic Pt₁Ag_xCu_yAu_15-x-y. Their structure-dependent photophysical properties were investigated due to the atomically precise structures of these nanoclusters. Cu-alloyed Cu_xAu_15-x showed intense phosphorescence and the highest singlet oxygen production efficiency. Moreover, the generation of ¹O₂ species from excited nanoclusters enabled Cu_xAu_15-x as a suitable catalyst for efficient photocatalytic oxidation of silyl enol ethers to produce α,β-unsaturated carbonyl compounds. The generality and applicability of the Cu_xAu_15-x catalysts toward different photocatalytic oxidations were assessed. Overall, this study presents an intriguing Au₁₅-based cluster series enabling an atomic-level understanding of structure-photophysical property correlations, which hopefully provides guidance for the fabrication of cluster-based catalysts with customized photocatalytic performance.