Thermal and Nonthermal Effects in Plasmon‐Mediated Electrochemistry at Nanostructured Ag Electrodes

Abstract

Hot carriers (HCs) and thermal effects, stemming from plasmon decays, are crucial for most plasmonic applications. However, quantifying these two effects remains extremely challenging due to the experimental difficulty in accurately measuring the temperature at reaction sites. Herein, we provide a novel strategy to disentangle HCs from photothermal effects based on the different traits of heat dissipation (long range) and HCs transport (short range), and quantitatively uncover the dominant and potential‐dependent role of photothermal effect by investigating the rapid‐ and slow‐response currents in plasmon‐mediated electrochemistry at nanostructured Ag electrode. Furthermore, the plasmoelectric surface potential is found to contribute to the rapid‐response currents, which is absent in the previous studies.

Quantitative Single-Particle Fluorescence Imaging Elucidates Semiconductor Shell Influence on Ag@TiO2 Photocatalysis

“…The mechanism insight obtained by our single-molecule analysis is complementary to the previous ensemble experiment and can promote an understanding of the structure–performance relationship of other metal–semiconductor hybrid NCs. In the future, it is necessary to improve the reaction system to study the contribution of heat and energetic charge carriers in specific photocatalytic reactions, which is very important for the design of new plasma NCs. , …”

“…In the future, it is necessary to improve the reaction system to study the contribution of heat and energetic charge carriers in specific photocatalytic reactions, which is very important for the design of new plasma NCs. 38,39 ■ MATERIALS AND METHODS Synthesis of Ag@TiO 2 NCs. Ag@TiO 2 core−shell NCs were synthesized by a three-step procedure.…”

Facile Surfactant‐, Reductant‐, and Ag Salt‐free Growth of Ag Nanoparticles with Controllable Size from 35 to 660 nm on Bulk Ag Materials

“…Nanostructured Ag has attracted intensive research interest for its unique physicochemical properties, which show great promise in a wide range of applications, such as optoelectronics, [1] catalysis, [2] sensors, [3] antibacterial, [4] and field‐enhanced spectroscopy [5] . Most of its physicochemical properties, e. g., the unrivaled light absorption and scattering ability as well as intense local amplification of electromagnetic fields enabled by the plasma oscillations of free electrons, are mostly dependent on its size and morphology [6,7] .…”

Structure-Adjustable Gold Nanoingots with Strong Plasmon Coupling and Magnetic Resonance for Improved Photocatalytic Activity and SERS

“…Noble metal nanocrystals featuring unique local surface plasmon resonance properties have been extensively investigated for a wide variety of applications in many fields, such as photocatalysis, sensing, photodetection, and surface-enhanced Raman scattering (SERS). − The excitation of surface plasmons of metal nanoparticles by incident light can concentrate electromagnetic radiation into dimensions smaller than the wavelength of the incident radiation and produce extremely strong local electromagnetic field, namely “hotspots”, which can be used to promote light–matter interactions and some chemical catalytic reactions. − In the catalytic process, the nonradiative decay of plasmons around hotspots can generate high-concentration and energetic hot electrons that can efficiently improve the rate of the catalytic reaction. Meanwhile, in the nonradiative decay of plasmons, the local heating effect is also induced, which can lead to an increase of temperature around the catalysts, thereby enhancing the speed of mass transfer and catalytic reaction. − In SERS, these hotspots can amplify the Raman signals for detection of biomolecules, pollutants, and pesticides at low concentrations, even down to the single-molecule level. − The local electromagnetic field of plasmonic metals strongly depends on the morphology, structure, and dimensionality. Metal nanocrystals with sharp corners and a porous structure usually have stronger electromagnetic field than the smooth and flat one.…”