Atomistic Understanding of Plasmon Mediated Photochemical Reactions*

Localized surface plasmon resonances (LSPRs) have attracted much recent attention for their potential in promoting chemical reactions with light. However, the mechanism of LSPR-induced chemical reactions is still not clear. This presentation will discuss the atomic-scale mechanism of plasmonic hot-carrier mediated chemical reaction exampled by H2 dissociation by employing TDDFT calculations and non-adiabatic molecular dynamics. The key observation is that there are nested excited states corresponding to both hot-electron excitation and charge transfer. These nested states cross, which facilitates the transitions depicted in the desorption induced by the electronic transitions model and the surface hopping model. Diabatization of these states shows that the charge transfer states are responsible for H2 dissociation, while the hot electron states do not. Moreover, we found the chemical reaction of molecule is tunable in plasmonic dimer.