“Hot” in Plasmonics: Temperature‐Related Concepts and Applications of Metal Nanostructures

Abstract

Recent advances in nonlinear optics, hot electrons for renewable energy (e.g., solar cells and water‐splitting), acousto‐optics, nanometalworking, nanorobotics, steam generation, and photothermal cancer therapy are reviewed here. In all these areas, one of the key enabling properties is the ability of metallic nanoparticles to harvest and control light at the subwavelength scale by supporting coherent electronic oscillations, called localized surface plasmon resonances (LSPRs). Various physical properties and potential areas of application emerge depending on the decay mechanism of the LSPR and, especially, depending on the considered timescale. The field of plasmonics has mainly been associated with manipulating electromagnetic near‐fields at the nanoscale, where absorption is an obstacle. However, plasmonic absorption leads to a stream of temperature‐related phenomena that have only recently attracted significant attention. The goal of this review is to highlight exciting new areas of research (such as nanorobotics, nanometalworking, or acousto‐optical techniques) and to survey the most recent progress in more established areas (such as hot electrons, photothermal therapy, and plasmonic steam generation). To set each research area in context, the text is organized around the thermal cycle of the nanoparticles.

Rational design of bimetallic photocatalysts based on plasmonically-derived hot carriers

“…The average power was set to avoid direct degradation of MB by photolysis and not to induce temperature-related effects. In this wavelength range, absorption of all types of the studied nanoparticles is similar and for the used pulsed laser power, the numerical estimates show that one laser pulse changes the temperature of the nanoparticles negligibly and the pulse repetition rate is low to ensure temperature relaxation between the pulses (50 ns interval between pulses), compared with a few ns nanoparticle-environment temperature relaxation time [30]. While the local temperature can be higher, we do not expect that temperature effects significantly influence the studied processes, which require electron transfer.…”

Nanoscale covalent organic frameworks as theranostic platforms for oncotherapy: synthesis, functionalization, and applications

“…The remarkable feature of inorganic PTAs, 11,465 e.g., gold nanorods, platinum quantum dots, and graphene nanosheets, is their ability to absorb and manipulate light at the subwavelength scale by supporting coherent electronic oscillation, which is called localized surface plasmon resonance (LSPR). 466 As energy transfers from light to electron and then from electron to lattice, the lattice transfers the energy to the environment in the form of heat, resulting in the photothermal effect. Furthermore, organic PTAs, 467,468 such as cyanine and phthalocyanine, have a larger p-conjugated system, which can efficiently absorb NIR light and get excited.…”

Photocatalytic Plasmon‐Enhanced Nitrogen Reduction to Ammonia

“…The excited electrons can relax nonradiatively, converting the absorbed light energy into heat which results in an increase in the local temperature. [ 40 ] The generated heat can help overcome the activation barrier for a chemical reaction. However, a high irradiance is often required to cause significant changes in the local temperature and drive a catalytic reaction via photothermal effect.…”