[Surface-enhanced Raman spectra and electrochemical studies on the inhibition of nickel corrosion by imidazole].

Surface-enhanced Raman scattering (SERS) spectrum of imidazole adsorbed on a nickel electrode in 0.1 mol x L(-1) KCl solution was investigated as a function of applied potential. The corrosion inhibition effects of imidazole on the nickel electrodes in 0.

Effect of intrinsic properties of metals on the adsorption behavior of molecules: benzene adsorption on Pt group metals.

Investigation of benzene adsorption on different metal surfaces closer to a practical system appears to be a very important intermediate stage to utilize the conclusion obtained on single-crystal surfaces. In this paper, we studied the electrochemical adsorption behaviors of benzene on roughened Pt group electrodes using surface enhanced Raman spectroscopy (SERS). The effects of potential, surface roughness, and benzene concentration were investigated.

pH-dependent electron transfer from re-bipyridyl complexes to metal oxide nanocrystalline thin films.

Photoinduced interfacial electron transfer (ET) from molecular adsorbates to semiconductor nanoparticles has been a subject of intense recent interest. Unlike intramolecular ET, the existence of a quasicontinuum of electronic states in the solid leads to a dependence of ET rate on the density of accepting states in the semiconductor, which varies with the position of the adsorbate excited-state oxidation potential relative to the conduction band edge. For metal oxide semiconductors, their conduction band edge position varies with the pH of the solution, leading to pH-dependent interfacial ET rates in these materials.

Orientation change of adsorbed pyrazine on roughened rhodium electrodes as probed by surface-enhanced Raman spectroscopy.

A surface-enhanced Raman spectroscopic (SERS) study of pyrazine adsorbed on roughened Rh electrodes was performed. Potential and concentration effects on the adsorption behavior of pyrazine were investigated. The SER spectra display four pairs of overlapping bands with the relative intensity of each pair being highly potential dependent, which has not been observed on other metals.

Surface-enhanced Raman scattering from transition metals with special surface morphology and nanoparticle shape.

This discussion focuses on our recent approaches at aiming to optimize surface-enhanced Raman scattering (SERS) activity for transition metals (group VIII B elements), by intentionally fabricating desired surface nanostructures or synthesizing nanoparticles. The SERS activity of transition metals critically depends on the surface morphology of electrodes and on size, shape and aggregation form of nanoparticles. A correct surface roughening procedure for transition-metal electrodes is indispensable for fabricating cauliflower-like nanostructures that show a higher SERS activity.

Binding interactions and Raman spectral properties of pyridine interacting with bimetallic silver-gold clusters.

The binding interactions between pyridine and bimetallic silver-gold clusters are investigated using density functional theory (DFT). The binding energies of pyridine-bimetallic cluster complexes indicate that the bonding depends strongly on the binding site (Au or Ag atom) and bonding molecular orbitals in a given configuration. The donation of the lone-pair electrons of the nitrogen of pyridine to an appropriate unoccupied orbital of each metal cluster plays an important role.

Synthesis of AgcoreAushell bimetallic nanoparticles for immunoassay based on surface-enhanced Raman spectroscopy.

Layered core-shell bimetallic silver-gold nanoparticles were prepared by coating Au layers over Ag seeds by a seed-growth method. The composition of Ag100-xAux particles can vary from x=0 to 30. TEM and SEM images clearly show that the bimetallic nanoparticles are of core-shell structure with some pinholes on the surface.

[Surface-enhanced raman spectra studies on roughened Zn electrode in alkaline solutions].

Electrochemical oxidation-reduction method was employed to roughen Zn electrode for obtaining SERS, and potential dependent surface enhanced Raman spectra (SERS) of roughened Zn electrode in KOH solution of different concentration wereobserved. The spectra of Zn electrode in various solutions had obvious differences which indicated the concentration of OH- had a great effect on the dissolution and passivation of zinc. Based on our experimental results, the authors attempt to analyse the behavior of zinc in alkaline and give the mechanism of its passivation.

[Synthesis and SERS characterization of silver nanocubes].

Silver nanocubes were synthesized by reducing silver nitrate with ethylene glycol in the presence of poly(vinyl pyrrolidone) based on the report by Xia's group. Silver nanocubes were immobilized on silicon wafers by self-assembly processes. SERS activity of silver nanocubes was detected by using pyridine and SCN- respectively as probe molecules.

Electrochemical and surfaced-enhanced Raman spectroscopic investigation of CO and SCN- adsorbed on Au(core)-Pt(shell) nanoparticles supported on GC electrodes.

Core-shell Au-Pt nanoparticles were synthesized by using a seed growth method and characterized by transmission electron microscopy, X-ray diffraction, and UV-vis spectroscopy. Au(core)-Pt(shell)/GC electrodes were prepared by drop-coating the nanoparticles on clean glassy carbon (GC) surfaces, and their electrochemical behavior in 0.5 M H2SO4 revealed that coating of the Au core by the Pt shell is complete.

[A theoretical study of the influence of interaction between transition metal atoms and carbon monoxide on infrared and Raman intensities of the C--O stretching vibration].

The structures and the spectral properties of the transition metal M-CO complexes have been investigated by performing the calculation of the hybrid density functional theory approach. The calculated results show that for each M-CO complex the infrared intensity of the C--O stretching mode is significantly larger than that of the M-C stretching mode and the bending modes. The Raman scattering factor of the C--O stretching mode is the largest among three modes.

[Adsorption studies of gamma-aminopropyltrimethoxysilane on iron surfaces by surface-enhanced Raman spectroscopy].

The films of gamma-aminopropyltrimethoxysilane (gamma-APS) on iron electrode surfaces were studied. The silane films were characterized by in-situ Surface-Enhanced Raman Spectroscopy (SERS). It has been found that the potential-dependent Surface-enhanced Raman Spectroscopy are useful for diagnosing the formation and structure of gamma-APS moieties bound onto the surface of metal substrates.

[SERS mechanism for rhodium electrode in the ultraviolet region].

Stable and good quality of Surface-Enhanced Raman Scattering (SERS) signal from net rhodium electrode in the ultraviolet region was observed for the first time by our group recently. In this paper, both qualitative and quantitative analyses are given to interpret the new experimental results mainly based on the electromagnetic field theory. The mechanisms of SERS for rhodium electrode in the ultraviolet region are mainly attributed to the lightning rod effect together with the weak surface plasmon resonance.

[In situ raman spectroscopic study on the oxidation of HCHO on a roughened platinum electrode].

The electrooxidation behavior of HCHO on a roughened platinum electrode was studied by cyclic voltammetry. Two factors that influence the electrooxidation behavior of HCHO, i.e.

Theoretical consideration on preparing silver particle films by adsorbing nanoparticles from bulk colloids to an air-water interface.

In our previous paper, a method for preparing enormous surface-enhanced Raman scattering (SERS) active substrates through the aggregation of silver particles trapped at an air-water interface was reported. Here, further efforts were devoted to investigate the origin of assembling silver particle films by adsorbing nanoparticles from bulk colloids to the air-water interface. It was revealed that it is thermodynamically favorable for a colloidal particle in bulk colloids to adsorb to the air-water interface; however, a finite sorption barrier between it and the nearby particles usually restrains the adsorption process.

Synthesis and properties of tadpole-shaped gold nanoparticles.

In this communication, gold nanoparticles with a tadpole shape were synthesized by a simple aqueous-phase chemical method. The unusual three-dimensional and crystallized structures were demonstrated by TEM, AFM, and HRTEM methods. The SEM and UV-visible absorption measurements and electrophoresis experiments revealed that the tadpoles had novel optical and electrical properties.

Adsorption and reaction at electrochemical interfaces as probed by surface-enhanced Raman spectroscopy.

Over the past three decades, surface-enhanced Raman spectroscopy (SERS) has gone through a tortuous pathway to develop into a powerful surface diagnostic technique for in situ investigation of surface adsorption and reactions on electrodes. This review presents the recent progress achieved mainly in our laboratory on the improvement of detection sensitivities as well as spectral, temporal, and spatial resolutions. Various surface roughening procedures for electrodes of different metals coupled with maximum use of a high-sensitivity confocal Raman microscope enable us to obtain good-quality SER spectra on the electrode surfaces made from net Pt, Ni, Co, Fe, Pd, Rh, Ru, and their alloys that were traditionally considered to be non-SERS active.

Optimizing detection sensitivity on surface-enhanced Raman scattering of transition-metal electrodes with confocal Raman microscopy.

Some points on how to improve the detection sensitivity of confocal Raman microscopy for the study of surface-enhanced Raman scattering (SERS) of transition-metal electrodes are discussed, including the careful design of the spectroelectrochemical cell, proper selection of the thickness of the solution layer, the binning of charge-coupled device (CCD) pixels, and appropriate setting of the notch filter. Various roughening methods for the Pt, Rh, Fe, Co, and Ni electrode surfaces have been introduced in order to obtain SERS-active surfaces. It has been shown that the appropriate roughening procedure and the optimizing performance of the confocal Raman microscope are the two most important factors to directly generate and observe SERS on net transition-metal electrodes.

[Confocal microprobe Raman spectroscopic study of electrochemical reduction of benzene on a platinum electrode].

The electrochemical reduction of benzene on a smooth Pt electrode has been studied by confocal microprobe Raman spectroscopy. The results show that benzene can be reduced directly to cyclohexane, which is insoluble in water, adhered onto the electrode surface to form the third phase. After the drops have been formed on the electrode surface, the relative concentration of benzene to cyclohexane in the drops will rather increase with prolonging the time at a certain electrode potential, although it decreases with the negative shift of the electrode potential at first.

[Surface-enhanced Raman spectrum studies of CO adsorbed on platinum electrodes in non-aqueous acetonitrile system].

In the non-aqueous acetonitrile solution, recurring to the confocal Raman system, we studied the catalysis and oxidation of carbon monoxide on the surface of platinum electrode utilizing surface-enhanced Raman spectrum (SERS). As the movement of the potential, the process of the catalysis and oxidation interacted with the surrounding molecular. In the present paper, the catalysis and oxidation of carbon monoxide on the surface of platinum electrode was not clearly observed, but also the dissociation of acetonitrile was discovered simultaneously.

[Competitive adsorption studies of pyridine and acetonitrile on platinum electrodes in non-aqueous system by surface-enhanced Raman spectroscopy].

In the non-aqueous acetonitrile solution, recurring to the confocal Raman system, we studied the intensively chemical adsorption of pyridine(Py) on the surface of platinum electrode utilizing surface-enhanced Raman scattering (SERS). With the change in the potential, the quantity and adsorptive orientation of the adsorbate also change, interacting on the surrounding molecules. In the present paper, the adsorption of Py on the surface of platinum electrode was not only clearly observed, but also the dissociation of acetonitrile was discovered simultaneously.

Surface-enhanced Raman scattering in the ultraviolet spectral region: UV-SERS on rhodium and ruthenium electrodes.

We report the first observation of surface-enhanced Raman scattering (SERS) excited with ultraviolet (UV) light from transition metal electrodes. Adsorbed pyridine and SCN- on rough rhodium (Rh) and ruthenium (Ru) electrodes, respectively, have been studied using 325 nm laser excitation. In contrast, the best enhancers in the visible and near infrared, silver and gold, do not produce UV-SERS.