Boosting Energy Flow by Manipulating Core–Satellite Dielectric Function Ratio of Heterostructures for Efficient Plasmon-Enhanced Ammonia Borane Dehydrogenation

Plasmonic heterogeneous nanoparticles, characterized by their remarkable light absorption properties and robust catalytic performance, are considered an ideal platform for efficiently driving photochemical conversions under mild conditions. In the design process of plasmonic heterostructures, facilitating energy transfer between plasmonic metals and catalytically active metals is crucial for enhancing photochemical conversion efficiency. In this study, we successfully constructed a core–satellite structure of Au–Rh NRs, which exhibited efficient energy charge transfer capabilities. Both experimental and theoretical calculations indicated that the Rh satellites, owing to their high imaginary part of the dielectric function, can effectively induce preferential plasmonic dissipation at catalytically active sites, thereby promoting photocatalytic reactions. Additionally, the distinctive architecture of these corn-shaped Au–Rh NRs significantly amplified the local electromagnetic field, accelerating the generation of hot electrons and the adsorption process of reactant molecules. Notably, through in situ single-particle fluorescence spectroscopy, we observed a complete quenching of the fluorescence signal from Au–Rh NRs in water. This phenomenon revealed that the enhanced local electromagnetic field provided an additional decay pathway for hot electrons originating from the Au–Rh nanostructure to water molecules, implying significant potential for the extraction and utilization of hot electrons in photocatalytic applications.