In Situ Surface Enhanced Raman Spectroscopy on Electrodes with Platinum and Palladium Nanoparticle Ensembles

Abstract

In situ Raman spectra have been obtained for different species (CN -, CO, H) adsorbed on nanostructured electrodes prepared by deposition of pure Pt and Pd nanoparticles (around 4 nm in size) on either gold or platinum electrodes in acidic solutions. The surface enhancement factor has been estimated on the basis of cyanide spectra obtained both at the surface and in solution. It attains a value as high as 550, around 3-4 times higher than that reported for roughened Pt electrodes for the same adsorbate. In the case of CO, typical bands for the stretching of the Pt/Pd-C and C-O bonds have been observed for low acquisition times (ca. 1 s), evidencing that pure Pt and Pd nanoparticles sustain significant surface enhancement effects. The spectra show mainly atop CO coordination for Pt nanoparticles whereas both linear and bridge CO are detected for Pd nanoparticles. The potential advantages of the nanoparticle-on-electrode approach in Raman spectroelectrochemical studies are highlighted.

Spectroelectrochemical behavior of 4-aminobenzenethiol on nanostructured platinum and silver electrodes

“…Interestingly, our experimental results obtained for silver at -0.5 V ( Fig. 2A) by the nanoparticles-on-electrode approach [12] agree with the SERS spectra obtained by Kim [31] after attaching Ag nanoparticles to the amine groups of 4-ABT adsorbed on smooth Pt [31]. Figure 6 shows three spectra obtained at the same surface position and with a power density of about 10 7 mWcm -2 .…”

“…In order to circumvent this limitation, different strategies have been used to obtain SERS information always with the aim of preparing a surface with a certain roughness or an appropriate morphology. Examples of these methods are the electrochemically activation of the surface (oxidation-reduction cycling [11]), the use nanoparticles deposited on a substrate, the so-called nanoparticles-on-electrode approach [12], or the Kim approach [31] among others. Interestingly, our experimental results obtained for silver at -0.5 V ( Fig.…”

“…Most other metals, including catalytic metals such as Pt or Pd are commonly considered as non-SERS actives because the efficient excitation of surface plasmon is unfavourable on such highly damping metal surfaces [7][8][9][10]. However, by suitable methods (among them the oxidation-reduction cycling [11] and nanoparticle-on-electrode approach [12])…”

Electrocatalytic oxidation of cyanide on copper-doped cobalt oxide electrodes

“…The experiments were performed in a three-electrode spectro-electrochemical cell made of polytetrafluoroethylene (PTFE). More details on this cell can be found in reference [43].…”

Study of the electro-oxidation of a recreational drug GHB (gamma hydroxybutyric acid) on a platinum catalyst-type electrode through chronoamperometry and spectro-electrochemistry

“…First, weak bands at 520 cm -1 and 1935 cm -1 can be observed and associated to the bridge CO, although a contribution of lineal CO also cannot be categorically rejected [21,22,25]. The CH stretching mode at 2841 cm -1 [26], and the OH stretching of the adsorbed water at 3149 and 3320 cm -1 (not shown in spectra of figure 5) [27] are also present.…”