Synthesis of Small-sized Trisoctahedral Gold Nanoparticles with High Catalytic Activity for Methanol Electrooxidation
摘要
In this study, we successfully synthesized trisoctahedral gold nanoparticles (TOH-Au NPs) with an average size of 45 nm along the longest axis using a seeded growth method. To the best of our knowledge, this represents the smallest reported size for TOH-Au NPs with {331} facet to date. By modulating the seed amount, we achieved precise size control, increasing the average particle size from 45 nm to 80 nm, accompanied by a corresponding red shift in plasmon resonances. Structural characterization via projection angle measurements confirmed that the synthesized TOH-Au NPs are enclosed by high-index {331} facets. These facets exhibit a high density of low-coordination sites, including step and kink atoms, which contribute to their exceptional electrocatalytic performance. Notably, the 45 nm TOH-Au NPs demonstrated the highest electrocatalytic activity, with an electrochemically active surface area (ECSA) of 1.239 m2/g, a mass-specific activity of 2.297 A/g, and an area-specific activity of 0.185 mA/cm2. This work not only establishes a robust method for the controlled synthesis of Au NPs but also highlights their potential as highly efficient catalysts for electrochemical applications.