Mechanistic Studies of Plasmon-Induced Chemical Reactions via Single-Molecule Measurements

Localized surface plasmons have attracted significant attention for nearly two decades. However, the understanding of their interactions with matter, especially in plasmon-induced chemical reactions, remains limited as it is difficult to experimentally analyze reaction processes due to the ultrafast relaxation and nanoscale localization of plasmons. This article presents our studies on plasmon-induced reactions at a single-molecule level by using a scanning tunneling microscope combined with light illumination. By comparing two molecular systems, we demonstrated that the electronic state of adsorbed molecules formed through hybridization with the metal surface plays a crucial role in determining the reaction mechanism. These findings, enabled by single-molecule analysis, provide experimental validation of previously hypothetical mechanisms and valuable insights for designing plasmonic catalysts.