Role of cavity strong coupling on single electron transfer reaction rate at electrode-electrolyte interface.

The physicochemical properties of molecules can be modulated through polariton formation under strong electromagnetic confinement. Here, we discuss the possibility of exploiting this phenomenon to increase the electron transfer rate at an electrode-electrolyte interface. Electron transfer theory under strong electromagnetic confinement can be extended to the electrode-electrolyte interface, and single-electron transfer reactions can be simulated using Gerischer's theory.

Impact of Surface Enhanced Raman Spectroscopy in Catalysis.

Catalysis stands as an indispensable cornerstone of modern society, underpinning the production of over 80% of manufactured goods and driving over 90% of industrial chemical processes. As the demand for more efficient and sustainable processes grows, better catalysts are needed. Understanding the working principles of catalysts is key, and over the last 50 years, surface-enhanced Raman Spectroscopy (SERS) has become essential.

Unlimiting ionic conduction: manipulating hydration dynamics through vibrational strong coupling of water.

The energy states of molecules and the vacuum electromagnetic field can be hybridized to form a strong coupling state. In particular, it has been demonstrated that vibrational strong coupling can be used to modify the chemical dynamics of molecules. Here, we propose that ion dynamics can be altered through modifications of the dynamic hydration structure in a cavity vacuum field.

Unveiling the Hidden Energy Profiles of the Oxygen Evolution Reaction via Machine Learning Analyses.

The oxygen evolution reaction (OER) is a crucial electrochemical process for hydrogen production in water electrolysis. However, due to the involvement of multiple proton-coupled electron transfer steps, it is challenging to identify the specific elementary reaction that limits the rate of the OER. Here we employed a machine-learning-based approach to extract the reaction pathway exhaustively from experimental data.

Understanding Spatial Distributions of Dye Molecules Coupled to the Surface Lattice Resonance Mode through Electrochemical Reaction Control.

The strong coupling, which is the light-matter interaction, leads to changes in the energy landscape of the chemical dynamics, resulting in the modulation of the reaction pathways. In this study, we achieved strong coupling between dye molecules dispersed in the polymer films and the surface lattice resonance mode, which is excited on plasmonic lattice arrays. In addition, we successfully tuned the coupling strength by introducing the electrochemical potential control method.

Inherent Promotion of Ionic Conductivity via Collective Vibrational Strong Coupling of Water with the Vacuum Electromagnetic Field.

Hydrogen bonding interactions among water molecules play a critical role in chemical reactivity, dynamic proton mobility, static dielectric behavior, and the thermodynamic properties of water. In this study, we demonstrate the modification of ionic conductivity of water through hybridization with a vacuum electromagnetic field by strongly coupling the O─H stretching mode of HO to a Fabry-Perot cavity mode. The hybridization generates collective vibro-polaritonic states, thereby enhancing the proton conductivity by an order of magnitude at resonance.

Rapid detection of donor-dependent photocatalytic hydrogen evolution by NMR spectroscopy.

Understanding molecular processes at nanoparticle surfaces is essential for designing active photocatalytic materials. Here, we utilize nuclear magnetic resonance (NMR) spectroscopy to track photocatalytic hydrogen evolution using donor molecules and water isotopologues. Pt-TiO catalysts were prepared and used for isotopic hydrogen evolution reactions using alcohols as electron donors.

Generation of Ultralong Liposome Tubes by Membrane Fusion beneath a Laser-Induced Microbubble on Gold Surfaces.

Membrane fusion (MF) is one of the most important and ubiquitous processes in living organisms. In this study, we developed a novel method for MF of liposomes. Our method is based on laser-induced bubble generation on gold surfaces (a plasmonic nanostructure or a flat film).

Unique Electronic Excitations at Highly Localized Plasmonic Field.

ConspectusUnder visible light illuminations, noble metal nanostructures can condense photon energy into the nanoscale region. By precisely tuning the metal nanostructures, the ultimate confinement of photoenergy at the molecular scale can be obtained. At such a confined photon energy field, various unique photoresponses of molecules, such as efficient visible light energy conversion processes or efficient multielectron transfer reactions, can be observed.

Room-Temperature Molecular Manipulation via Plasmonic Trapping at Electrified Interfaces.

For the motion control of individual molecules at room temperature, optical tweezers could be one of the best approaches to realize desirable selectivity with high resolution in time and space. Because of physical limitations due to the thermal fluctuation, optical manipulation of small molecules at room temperature is still a challenging subject. The difficulty of the manipulation also emerged from the variation of molecular polarizability depending on the choice of molecules as well as the molecular orientation to the optical field.

Tuning Electrogenerated Chemiluminescence Intensity Enhancement Using Hexagonal Lattice Arrays of Gold Nanodisks.

Electrogenerated chemiluminescence (ECL) microscopy shows promise as a technique for mapping chemical reactions on single nanoparticles. The technique's spatial resolution is limited by the quantum yield of the emission and the diffusive nature of the ECL process. To improve signal intensity, ECL dyes have been coupled with plasmonic nanoparticles, which act as nanoantennas.

Spatial distribution of active sites for plasmon-induced chemical reactions triggered by well-defined plasmon modes.

Plasmon-induced chemical reactions triggered by near-infrared light illumination might enable efficient photo energy conversion. Here, electrochemical oxidative polymerization of a conductive polymer was conducted on plasmonic photoconversion electrodes. The absolute electrochemical potential of the generated holes was estimated from the redox potentials of the monomers.

Ultra-fine electrochemical tuning of hybridized plasmon modes for ultimate light confinement.

Highly reproducible control of metal plasmonic nanostructures has been achieved via precise tuning of the electrochemical Au dissolution reaction that occurs at the surfaces of well-defined bridged nanodisk dimer structures on an atomic scale. It was found that the scattering intensity is strongly suppressed during the transition from the conductive mode to the gap mode of the localized surface plasmon resonance during the period when the gap is formed and increased between Au nanodisks. The characteristic shift of the plasmon mode during this suppression of the scattering intensity verifies the excitation of the bonding quadrupolar mode, which appears only at sub-nanometer gap distances (d < 1 nm).

Potential energy shift of the Fermi level at plasmonic structures for light-energy conversion determined by graphene-based Raman measurements.

Single layer graphene was used to determine the electrochemical potential of plasmonic nano-structures for photoelectrochemical energy conversions. From electrochemical Raman measurements of the graphene layer under near-infrared light, illumination has revealed the relationship between the photoenergy conversion ability and the Fermi level of the plasmonic structure. The determination is based on in situ monitoring of G and 2D Raman bands of the graphene layer on plasmonic structures.

Plasmonic Manipulation of DNA using a Combination of Optical and Thermophoretic Forces: Separation of Different-Sized DNA from Mixture Solution.

We demonstrate the size-dependent separation and permanent immobilization of DNA on plasmonic substrates by means of plasmonic optical tweezers. We found that a gold nanopyramidal dimer array enhanced the optical force exerted on the DNA, leading to permanent immobilization of the DNA on the plasmonic substrate. The immobilization was realized by a combination of the plasmon-enhanced optical force and the thermophoretic force induced by a photothermal effect of the plasmons.

Nonzero Wavevector Excitation of Graphene by Localized Surface Plasmons.

Electrochemical surface-enhanced Raman scattering measurements of single layer graphene provide unique information on resonant excitation induced by localized surface plasmons under controlled electron or hole doping. The highly confined electromagnetic field from the LSPs of the Au nanodimer structures prepared on defect-free graphene can generate holes and electrons of the electrochemical potentials beyond the limit of far-field light illumination. The electrochemical in situ SERS spectra prove nonzero wavevector excitation through the observation of normally forbidden Raman bands in graphene.

Present and Future of Surface-Enhanced Raman Scattering.

The discovery of the enhancement of Raman scattering by molecules adsorbed on nanostructured metal surfaces is a landmark in the history of spectroscopic and analytical techniques. Significant experimental and theoretical effort has been directed toward understanding the surface-enhanced Raman scattering (SERS) effect and demonstrating its potential in various types of ultrasensitive sensing applications in a wide variety of fields. In the 45 years since its discovery, SERS has blossomed into a rich area of research and technology, but additional efforts are still needed before it can be routinely used analytically and in commercial products.

Photoelectrochemical Formation of Polysulfide at PbS QD-Sensitized Plasmonic Electrodes.

Effective electron-hole separation is a key to enhance photoenergy conversion of semiconductor quantum dot (QD)-sensitized plasmonic solar cells. However, in contrast to intense studies on electron transfer, hole transfer from QDs and consequent chemical reactions with donors in electrolytes remain unclear. Herein, in situ electrochemical surface-enhanced Raman scattering (SERS) measurement on a PbS QD-sensitized TiO/Au/TiO photoelectrode indicated formation of -octasulfur (α-S) via tuning the electrochemical potential.

Revealing High Oxygen Evolution Catalytic Activity of Fluorine-Doped Carbon in Alkaline Media.

Oxygen evolution reactions (OER) are important reactions for energy conversion. Metal-free carbon-based catalysts potentially contribute to the catalytic materials for OER. However, it has been difficult to understand the intrinsic catalytic activity of carbon materials, due to catalyst decomposition over the course of long-term reactions.

Plasmonically enhanced electromotive force of narrow bandgap PbS QD-based photovoltaics.

Electromotive force of photovoltaics is a key to define the output power density of photovoltaics. Multiple exciton generation (MEG) exhibited by semiconductor quantum dots (QDs) has great potential to enhance photovoltaic performance owing to the ability to generate more than one electron-hole pairs when absorbing a single photon. However, even in MEG-based photovoltaics, limitation of modifying the electromotive force exists due to the intrinsic electrochemical potential of the conduction band-edges of QDs.

Advantage of semi-ionic bonding in fluorine-doped carbon materials for the oxygen evolution reaction in alkaline media.

Metal-free carbonaceous catalysts have potential applications for oxygen evolution reaction (OER) devices because of their low-cost and abundant supply. We report that fluorine-doped carbon black is an active catalyst for OER. Fluorine-doped carbon black (F-KB) is simply synthesized by the pyrolysis of KETJENBLACK (KB) as carbon substrate with Nafion as fluorine precursor.

Sensitive Raman Probe of Electronic Interactions between Monolayer Graphene and Substrate under Electrochemical Potential Control.

In situ electrochemical Raman spectroscopic measurements of defect-free monolayer graphene on various substrates were performed under electrochemical potential control. The G and 2D Raman band wavenumbers (ω, ω) of graphene were found to depend upon the electrochemical potential, i.e.

Electrochemical surface-enhanced Raman scattering measurement on ligand capped PbS quantum dots at gap of Au nanodimer.

The vibrational characteristics of ligand-capped lead sulfide (PbS) quantum dots (QDs) were clarified via electrochemical surface-enhanced Raman spectroscopy (EC-SERS) using a hybridized system of gold (Au) nanodimers and PbS QDs under electrochemical potential control. Enhanced electromagnetic field caused by the coupling of QDs with plasmonic Au nanodimers allowed the characteristic behavior of the ligand oleic acid (OA) on the PbS QD surface to be detected under electrochemical potential control. Binding modes between the QDs and OA molecules were characterized using synchronous two-dimensional correlation spectra at distinct electrochemical potentials, confirming that the bidentate bridging mode was probably the most stable mode even under relatively negative potential polarization.

Nanoscale control of plasmon-active metal nanodimer structures via electrochemical metal dissolution reaction.

Herein, we report the control of the optical properties of metal nanodimer structures using electrochemical metal dissolution reactions. The reaction rate could be precisely tuned by changing the electrochemical potential and, as a consequence, fine tuning of the size and gap distance of metal nanodimers was achieved as the functions of applied potential and polarization time. The observed linear correlation between the scattering intensity and charge resulting from nanostructure dissolutions suggested that the surface dissolution rate was 0.