Fabrication of plasmonic Au–Pd alloy nanoparticles for photocatalytic Suzuki–Miyaura reactions under ambient conditions
The Suzuki–Miyaura reaction is one of the most popular and efficient routes for the formation of carbon–carbon bonds in both laboratorial and industrial synthetic processes. Here, we report for the first time that a Au–Pd/TiO2 catalyst could be utilized efficiently for Suzuki–Miyaura reactions at ambient conditions under visible light with high activity and reusability. Mechanistic investigation by means of experimental methods revealed that through the strong local surface plasma resonance of Au under the visible light, the hot electrons of Au could be injected into Pd in the bimetallic nanoparticles, thus facilitating activation of the aryl halides. Meanwhile, the electropositive Au tended to gain electrons from TiO2, resulting in the separation of the photogenerated electron/hole pairs of TiO2, which enabled the holes to activate aryl boronic acids. This Au–Pd/TiO2 catalyst not only expands the application scope of Suzuki–Miyaura reactions under mild conditions but will also inspire further exploitation of the direct harvesting of visible light by nanomaterials for a wide range of chemical reactions.