Inverted Temperature Gradients in Gold-Palladium Antenna-Reactor Nanoparticles
Abstract
In addition to enhanced fields and possible charge transfer, the concentration of photothermal energy at the nanoscale is a foundation of plasmon-driven photochemistry. We demonstrate a further enhancement of heat localization during the dissipation of energy in a bimetallic antenna--reactor system with palladium satellites attached to a gold nanoparticle. After pulsed excitation of the gold core, the satellites collect nearly all photothermal energy and heat up by 180\,K while the light-absorbing gold core remains much colder. By comparing transient absorption dynamics of a series of bimetallic nanoparticles with a three-temperature model, we can precisely assess the temperatures of the electronic and vibrational subsystems. We find a strong inverted temperature gradient that opposes the direction of energy input and concentrates the light energy at the active catalytic nanosite.
Keywords
Cite
@article{arxiv.2501.02566,
title = {Inverted Temperature Gradients in Gold-Palladium Antenna-Reactor Nanoparticles},
author = {Felix Stete and Shivani Kesarwani and Charlotte Ruhmlieb and Florian Schulz and Matias Bargheer and Holger Lange},
journal= {arXiv preprint arXiv:2501.02566},
year = {2025}
}
Comments
8 pages, 4 Figures