jz6b00283_si_liveslides.zip (5.57 MB)
Slow Relaxation of Surface Plasmon Excitations in Au55: The Key to Efficient Plasmonic Heating in Au/TiO2
Version 2 2016-07-22, 13:37
Version 1 2016-07-21, 17:03
dataset
posted on 2016-07-22, 13:37 authored by Oshadha Ranasingha, Hong Wang, Vladimír Zobač, Pavel Jelínek, Gihan Panapitiya, Amanda J. Neukirch, Oleg V. Prezhdo, James P. LewisGold
nanoparticles distinguish themselves from other nanoparticles
due to their unique surface plasmon resonance properties that can
be exploited for a multiplicity of applications. The promise of plasmonic
heating in systems of Au nanoparticles on transition metal oxide supports,
for example, Au/TiO2, rests with the ability of the surface
plasmon in Au nanoparticles to effectively transfer energy into the
transition metal oxide. Here, we report a critical observation regarding
Au nanoparticle (Au55) surface plasmon excitations, that
is, the relaxation of the surface plasmon excitation is very slow,
on the order of several picoseconds. Starting from five plasmon states
in Au55 nanoparticles using nonadiabatic molecular dynamics
simulations, we find that the relaxation time constant resulting from
these simulations is ∼6.8 ps, mainly resulting from a long-lived
intermediate state found at around −0.8 eV. This long-lived
intermediate state aligns with the conduction band edge of TiO2, thereby facilitating energy transfer injection from the
Au55 nanoparticle into the TiO2. The current
results rule out the previously reported molecular-like relaxation
dynamics for Au55.