Tuesday, 11 October 2022: 10:10
Room 217 (The Hilton Atlanta)
Plasmonic nanomaterials are promising catalysts for selective, green, and efficient photo-driven processes, however currently the mechanisms involved in plasmon-driven catalysis are under debate. Contributions from processes such as vibrational and electronic energy transfer, electron transfer, or electromagnetic field enhancement could all lead to modified potential energy landscapes in the plasmon-molecule system. We have developed ultrafast and electrochemical surface-enhanced Raman spectroscopic (SERS) techniques to probe the contribution of these processes on the nanometer length scale and femtosecond timescale. This talk will highlight the use of these approaches in quantifying the rate, yield, and lifetime of plasmon-to-molecule charge transfer. We monitor changes in the vibrational spectra of adsorbed molecular species following plasmon excitation with picosecond time resolution, and quantify how many molecules are reduced and how quickly they undergo back electron transfer. Overall, these methods allow for quantification of the ultrafast reducing power of a plasmonic surface, and suggest routes for optimizing plasmonic systems for efficient and selective photochemistry.