Fast Surface Restructuring within the Gap of Au Nanocube Dimer for the Enhancement of Catalytic Efficiency

Identification of the catalytic dynamics and plasmonic effects plays a critical role in the design of heterogeneous catalysts. However, the knowledge of plasmonic effect on catalytic dynamics remains limited at the single-particle level. Using the non-fluorescent amplex red to fluorescent resorufin as a model reaction, significant enhancement in catalytic efficiency from the coupled Au nanocube dimer (AuCD) was clearly revealed with the single-molecule fluorescence microscopy. AuCD exhibits noticeably higher catalytic efficiency than the monomer, which is attributed to the spontaneous dynamic surface restructuring. Spatiotemporally resolved dynamics suggest that the active catalytic sites essentially originate from the plasmonic nanogap where an electromagnetic (EM) hot spot exists. The enhanced EM field accelerates the generation of hot carriers and promotes the spontaneous surface restructuring by enhancing the lattice vibrations, which ultimately improves the catalytic activity. These microscopic views provide new insights into the effect of EM fields on surface restructuring dynamics of nanocatalysts.

Automated summary

Identification of catalytic dynamics and plasmonic effects is crucial for designing heterogeneous catalysts. However, the understanding of the plasmonic effect on catalytic dynamics at the single-particle level is still limited. Using single-molecule fluorescence microscopy, researchers found that the coupled Au nanocube dimer (AuCD) exhibited a significant enhancement in catalytic efficiency. This enhancement was attributed to the spontaneous dynamic surface restructuring, which was influenced by the plasmonic nanogap and the electromagnetic hot spot.