Real-Space Studies of Plasmon-Induced Dissociation Reactions with an STM

Abstract

Abstract Molecular bond dissociation and formation reactions induced by localized surface plasmons of metal nanostructures are promising reactions in terms of the effective utilization of sunlight. The plasmon has a potential not only to enhance photochemical reactions but also to enable efficient novel reaction pathways. However, the reaction mechanism is still veiled because it is difficult to directly observe the reactions caused at the localized field of the plasmon near the metal surfaces. For the visualization of the reactions induced by the plasmon at a single-molecule level, we have applied a scanning tunneling microscope (STM). Bond dissociation reactions were induced by the plasmon excited at a nanogap between the STM tip and a metal substrate under light irradiation. The STM analyses combined with density functional theory calculations provided mechanistic insights into the plasmon-induced dissociation reactions.