Alloy Plasmonics - Fundamentals and Applications
Doctoral thesis, 2022
The second theme in this thesis is plasmon-enhanced catalysis. In this field, there is a continuous discussion regarding the reaction enhancing mechanisms when noble metal catalyst nanoparticles are irradiated with visible light during a catalytic reaction. Here we investigated the role of photothermal enhancement of reactions by tailoring the catalytic activity of nanofabricated particles without radiation by means of alloying Pd with Au, while keeping the optical absorption cross section constant, as confirmed by electrodynamics simulations using our dielectric function library as the input.
Temperature is a crucial parameter during catalysis in general and photocatalysis in specifically. However, it is intrinsically difficult to measure the temperature of nanoparticles with traditional methods. Therefore, we presented a hydrogen nanothermometry method that allows measuring nanoparticle temperature directly and noninvasively via the temperature dependent phase transition during Pd-hydride formation. We showed that the Pd particle temperature during light-induced heating can be measured with a resolution of 1 °C.
sensing
gold-palladium
nanothermometry
palladium-hydride
nanoalloys
photothermal
plasmonics
CO oxidation
heterogeneous catalysis
dielectric function
Author
Christopher Tiburski
Chalmers, Physics, Chemical Physics
A Library of Late Transition Metal Alloy Dielectric Functions for Nanophotonic Applications
Advanced Functional Materials,;Vol. 30(2020)
Journal article
Optical Hydrogen Nanothermometry of Plasmonic Nanoparticles under Illumination
ACS Nano,;Vol. In Press(2022)
Journal article
Engineering Optical Absorption in Late Transition-Metal Nanoparticles by Alloying
ACS Photonics,;Vol. 10(2023)p. 253-264
Journal article
A Microshutter for the Nanofabrication of Plasmonic Metal Alloys with Single Nanoparticle Composition Control
ACS Nano,;Vol. In Press(2023)
Journal article
At the same time, the concept of alloying is still in its infancy in younger areas of science and technology, like in the field of nanoplasmonics that is focused on investigating the interaction of light with nanoparticles. The word nanoparticle gives the small but distinct hint that we are in the world of nanometer sized objects. One nanometer compares to a meter like a euro coin to the size of our planet. In plasmonic applications the use of alloys is to-date still limited to a small number of systems. This is mainly due to a lack of understanding of the fundamental optical properties of alloys in general, and a lack of complex dielectric functions of alloys in particular. The latter is critical since dielectric functions are a key resource for being able to predict the response of nanostructures to light by means of modeling or electrodynamic simulations. Such predictions, in turn, are important to both rationally design and fine-tune alloy nanostructures for their intended applications.
In this thesis, I have contributed to the discovery of such dielectric functions for ten different alloy systems, and then applied them together with a range of nanofabricated alloy nanoparticle systems in combined experimental and theoretical studies of alloy nanoparticles in the world of plasmonics and catalysis.
Wallenberg Academy Fellow 2016
Knut and Alice Wallenberg Foundation (KAW2016.0210), 2017-07-01 -- 2022-06-30.
Areas of Advance
Nanoscience and Nanotechnology
Subject Categories
Physical Chemistry
Physical Sciences
Nano Technology
Metallurgy and Metallic Materials
Condensed Matter Physics
Infrastructure
Chalmers Materials Analysis Laboratory
Nanofabrication Laboratory
ISBN
978-91-7905-720-6
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 5186
Publisher
Chalmers
PJ
Opponent: Prof. Guillaume Baffou, Institut Fresnel, CNRS, Aix Marseille University, Marseille