Synthesis of a Gold-Silver Alloy Nanocluster within a Ring-Shaped Polyoxometalate and Its Photocatalytic Property.

Alloying is an effective method for modulating metal nanoclusters to enrich their structural diversity and physicochemical properties. Recent investigations have demonstrated that polyoxometalates (POMs) can act as effective multidentate ligands for silver (Ag) nanoclusters to endow them with synergistic properties, reactivity, catalytic properties, and stability. However, the application of POMs as ligands has been confined predominantly to monometallic nanoclusters. Herein, we report a synthetic method for fabricating surface-exposed gold (Au)-Ag alloy nanoclusters within a ring-shaped POM ([P₈W₄₈O₁₈₄]^40-). Reacting an Ag nanocluster stabilized by the ring-shaped POM with Au ions (Au⁺) was found to substitute several Ag atoms at the core of the nanocluster with Au atoms. The resultant {Au₈Ag₂₆} alloy nanocluster demonstrated superior photocatalytic activity and stability compared to the pristine Ag nanocluster in the aerobic oxidation of α-terpinene under visible-light irradiation. These findings provide fundamental insights into the formation and catalytic properties of POM-stabilized alloy nanoclusters and advance exploration into the synthesis and applications of diverse metal nanoclusters.