Kinetics of oxygen reduction on gold nanoparticle/multi-walled carbon nanotube hybrid electrodes in acid media

In this paper, the electrochemical reduction of oxygen has been studied on gold nanoparticle/multi-walled carbon nanotube (AuNP/MWCNT) modified glassy carbon (GC) electrodes in 0.5 M H₂SO₄ using the rotating disk electrode (RDE) method. The AuNP/MWCNT catalysts were prepared by chemical deposition of AuNPs onto MWCNTs spontaneously grafted with 4-nitrophenyl groups. The composite electrode was characterised by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV). The oxygen reduction behaviour of these electrodes was compared with that of a bulk gold electrode. The AuNP/MWCNT catalyst showed a pronounced electrocatalytic activity towards O₂ reduction in acid media. The half-wave potential of O₂ reduction on the AuNP/MWCNT catalyst shifted ca 80 mV to more positive potentials as compared to that of a polished Au electrode. The kinetic parameters of oxygen reduction were determined and the specific activity of the hybrid electrode was slightly higher than that of the bulk Au electrode.     

Electrochemical behavior of Pd–Pt–Au alloys

Pd–Pt–Au alloys were prepared as limited volume electrodes by metal codeposition at constant potential from chloride solutions. Alloy surface state was examined by scanning electron microscopy (SEM) and Auger electron spectroscopy (AES). The alloys were characterized electrochemically in acidic solution (0.5 M H₂SO₄) by cyclic voltammetry (CV). Potential regions of hydrogen electrosorption and surface oxidation are clearly distinguishable. The influence of electrode potential and alloy composition on the amount of absorbed hydrogen was investigated. Hydrogen absorption capacity of Pd–Pt–Au alloys increases with decreasing potential and the α–β phase transition is shifted positively with increasing Au content and negatively with increasing Pt content in the bulk. At relatively high potentials the amount of absorbed hydrogen exhibits a maximum for ca. 15–25 at.% Au in the bulk, while for low potentials a monotonic decrease in hydrogen absorption capacity with increasing bulk concentration of both alloying metals (Pt, Au) is observed.     

Bismuth UPD on the modified Au(1 1 1) electrode

The bismuth UPD was studied on Au(1 1 1) electrodes modified by silver intermediates and adsorbed thymine. Cyclic voltammetry, potential step experiments and X-ray photoelectron spectroscopy were used for investigation. The results were compared to the results of the analogous experiments performed on bare Au(1 1 1) and on bulk silver. In the first part it is shown that the Bi UPD on Ag_ML/Au(1 1 1) differs completely from the UPD on Au(1 1 1) as well as on bulk Ag due to changed electronic properties of the substrate. The 2nd part focuses on the Bi UPD in presence of the nucleobase thymine. Thymine undergoes a reorientation from the chemisorbed state to the physisorbed state on Au(1 1 1) at potentials where the Bi UPD takes place. During the UPD adsorbed thymine is replaced by Bi species on the electrode surface. It does not re-adsorb on top of the deposited Bi layer. An energetic advantage due to re-adsorption on topmost layer as described for the Cu UPD on thymine modified Au(1 1 1) does not occur.     

Nanoporous gold particles modified titanium electrode for hydrazine oxidation

A nanoporous gold particles modified titanium electrode (Au/Ti) was prepared by using a hydrothermal method. Gold nanoparticles were stably immobilized on the Ti surface from a mixture of aqueous HAuCl₄/polyethylene glycol (PEG) to form a nanoporous network texture. Electrocatalytic activity of the Au/Ti towards hydrazine oxidation in 1 M NaOH solution was assessed utilizing cyclic voltammetry (CV), linear scanning voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). At the Au/Ti electrode, hydrazine oxidation in 1 M NaOH took place at a potential of −0.55 V (vs. Ag, AgCl) which was 0.53 V less than polycrystalline Au electrode. The Au/Ti electrode also presented much larger current density of hydrazine oxidation than Au electrode. Cyclic voltammetric responses of the Au/Ti electrode showed an irreversible electro-oxidation process of hydrazine. Linear plots of the reduction peak current density from the CVs of the Au/Ti vs. hydrazine concentration provided a potential detection of low concentration hydrazine. The kinetic parameters such as the number of electrons transferred in rate-determining step and total numbers of electrons involved in the hydrazine oxidation were determined using CVs and LSVs. CVs at the Au/Ti electrode also illustrated (relatively) weak interactions of hydrazine with electrode surface at all stages of the hydrazine oxidation process. Further, EIS data showed significantly high electrocatalytic activity of the Au/Ti electrode for hydrazine oxidation in alkaline solutions.     

Comparative study on the influence of temperature,electrode potential and alloy bulk composition on hydrogen electrosorption into Pd–Pt and Pd–Au alloys

Hydrogen electrosorption into Pd-rich (>70% at. Pd in the bulk) Pd–Pt and Pd–Au alloys has been studied in acidic solutions (0.5 M H₂SO₄) using cyclic voltammetry and chronoamperometry. The influence of temperature (in the range between 283 and 328 K), electrode potential and alloy bulk composition on hydrogen electrosorption properties is presented. It has been found that with increasing temperature the maximum amount of absorbed hydrogen decreases and the potential of absorbed hydrogen oxidation peak and the potential of the α–β phase transition are shifted negatively. Pd alloying with Pt or Au results in lower potential of absorbed hydrogen oxidation peak and lower maximum amount of absorbed hydrogen. The region of the α–β phase transition for Pd–Pt alloys is placed at lower potentials as compared to pure Pd indicating lower thermodynamic stability of the β-phase. In the case of Pd–Au alloys the phase transition region is placed at higher potentials indicating higher thermodynamic stability of the β-phase. The values of time needed for electrode saturation with hydrogen and its removal decrease with increasing temperature and increasing bulk content of the alloying metals. The results have confirmed earlier suggestions that in the presence of both α- and β-phases of absorbed hydrogen the slow process of the phase transition controls the rate of the overall electrosorption process in thin Pd-based electrodes. The amounts of electrosorbed hydrogen for α- and β-phase boundaries, i.e. α_max and β_min, have been determined from the integration of the initial parts of current–time responses in hydrogen absorption and desorption processes.     

Electrodeposited indigotetrasulfonate film onto glutaraldehyde-cross-linked poly-l-lysine modified glassy carbon electrode for detection of dissolved oxygen

The nano composited film of indigotetrasulfonate (ITS) electrodeposited onto poly-l-lysine (PLL)–glutaraldehyde (GA) (ITS/PLL–GA) was modified on glassy carbon electrode (GCE) by multiple scan cyclic voltammetry. Composited of the proposed film was characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), electrochemical quartz crystal microbalance (EQCM), electrochemical impedance spectroscopy (EIS), and UV–vis spectrum for the absorption at λ_max at 566 nm. For the electrocatalytic reduction of dissolved oxygen, ITS/PLL–GA film modified electrodes was determined in 0.1 M acetate buffer solution (pH 5.6) by cyclic voltammetry and rotating disk electrode voltammetry. This dissolved oxygen electrochemical sensor exhibited a linear response range (from 0 to 178.4 μM, R² = 0.9949), lowest detection limit (2.2 μM), lowest overpotential at −0.09 V, high sensitivity (906 μA mM⁻¹) and relative standard deviation (RSD) for determining dissolved oxygen (n = 3) was 4.2%. In addition, the ITS/PLL–GA/GCE was advantageous in terms of its simple preparation, specificity, stability and the ability of regeneration.     

Electroanalytical properties of haemoglobin in silica-nanocomposite films electrogenerated on pyrolitic graphite electrode

Haemoglobin (Hb) modified electrochemical devices have been prepared by Hb encapsulation in silica sol–gel films (SiO₂), which were generated by electro-assisted deposition onto pyrolitic graphite electrodes (PGEs). The stability and electrocatalytic activity of Hb entrapped into SiO₂ network was substantially enhanced in the presence of cationic surfactant (CTAB) and Au nanoparticles (Au-NPs). The composition of sol–gel synthesis medium, i.e., molar ratio of silica precursor to water, contents of Hb, CTAB and Au-NPs, as well as the conditions of electrogeneration had a great influence on the electrocatalytic activity of Hb on PGE surface. The electrochemical response of the PGE modified with the composite SiO₂–Hb–CTAB–Au-NPs film was found to vary linearly with the concentration of dissolved oxygen in solution and this was exploited to determine this analyte in the tap water with detection limit 0.12 mg L⁻¹. The electrocatalytic current of dissolved oxygen was also found to decrease in the presence of the antivirus drug––amino derivative of adamantane (rimantadine)––which opens the way to the determination of this drug with detection limit 0.3 mg L⁻¹ using PGE modified with SiO₂–Hb–CTAB–Au-NPs nanocomposite film.     

Amperometric determination of hydrogen peroxide on surface of a novel PbPCNF-modified carbon-ceramic electrode in acidic medium

This work describes the electrochemical behavior of lead pentacyanonitrosylferrate (PbPCNF) film immobilized on the surface of carbon-ceramic electrode (CCE) and its electrocatalytic activity toward the reduction of hydrogen peroxide in acidic medium. The electrode was prepared by electroless derivatization of Pb-doped carbon-ceramic electrode surface to the redox active PbPCNF solid film, in the presence of sodium pentacyanonitrosylferrate, Na₂[Fe(CN)₅NO], (PCNF). The morphology and the composition of the PbPCNF-modified CCE were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and Fourier transform infrared (FTIR) techniques. Various experimental parameters influencing the electrochemical behavior of the modified electrode were optimized by varying the supporting electrolyte, potential scan rates and solution pH. The modified electrode showed an excellent electrocatalytic behavior toward the reduction of hydrogen peroxide in 0.5 M KNO₃ at pH 4. The sensor exhibited a good linear response for H₂O₂ concentration over the range 0.5–58.75 μM with a detection limit of 0.4 μM (S/N = 3). The interferences of dopamine (DA), uric acid (UA), and ascorbic acid (AA) were negligible in the determination of H₂O₂. The proposed sensor showed good stability, reproducibility and outstanding for long-term use.     

Simultaneous determination of adenine and guanine utilizing PbO2-carbon nanotubes-ionic liquid composite film modified glassy carbon electrode

A novel and reliable electrochemical sensor based on PbO₂-carbon nanotubes-room temperature ionic liquid (i.e., 1-butyl-3-methylimidazolium hexafluorophosphate, BMIMPF6) composite film modified glassy carbon electrode (GCE) (PbO₂–MWNT–RTIL/GCE) was proposed for simultaneous and individual determination of guanine and adenine. The guanine and adenine oxidation responses were monitored by differential pulse voltammetric (DPV) measurement. Compared with the bare electrode, the PbO₂–MWNT–RTIL/GCE not only significantly enhanced the oxidation peak currents of guanine and adenine, but also lowered their oxidation overpotentials, suggesting that the synergistic effect of PbO₂, MWNT and RTIL could dramatically improve the determining sensitivity of guanine and adenine. The PbO₂–MWNT–RTIL/GCE showed good stability, high accumulation efficiency and enhanced electrocatalytic ability for the detection of guanine and adenine. Besides, the modified electrode also exhibited good behaviors in the simultaneous detection of adenine and guanine with the peak separation of 0.29 V in 0.1 M pH 7.0 phosphate buffer solution (PBS). Under the optimal conditions, the detection limit for individual determination of guanine and adenine was 6.0 × 10⁻⁹ M and 3.0 × 10⁻⁸ M (S/N = 3), respectively. The proposed method for the measurements of guanine and adenine in herring sperm DNA was successfully applied with satisfactory results.     

Quasi-reversible two-electron reduction of oxygen at iodine submonolayer-coated gold electrode in alkaline media

Oxygen reduction reaction (ORR) was investigated using polycrystalline gold (Au (poly)) electrode modified with chemisorbed iodine (I_(ads)) submonolayer (sub I_(ads)) in O₂-saturated 0.1 M KOH solution. The sub I_(ads) was tailored by potential-dependent partial reductive desorption of I_(ads) from its full monolayer. The Au (1 1 1) facet of the Au (poly) electrode was considered to remain bared at the sub I_(ads)/Au (poly) electrode. The interesting finding of the present study is that (unlike the bare Au (poly) electrode) the sub I_(ads)/Au (poly) electrode exhibited a quasi-reversible two-electron reduction of O₂ in alkaline media. The probable origin of the observed quasi-reversible behavior of the ORR is discussed. Experimental investigations were performed using cyclic and steady-state voltammetric, amperometric and coulometric techniques.     

Reduction of nitrite on tin-modified noble metal electrodes

The electrocatalytic activity and product distribution of the nitrite reduction on Sn-modified noble metal (Ru, Pd, Rh, Pt, and Ir) electrodes, as well as unmodified noble metal electrodes, were examined in a 0.1 M HClO₄ solution. The most effective coverages were 0.35 and 0.55 for the Sn/Pt and Sn/Pd, respectively. The activity of the Sn/Ru, Sn/Rh, and Sn/Ir electrodes simply increased with an increase in the Sn coverage. From the maximum current densities at −0.1 V, the orders of the reduction activity for the unmodified and Sn-modified electrodes were Ir > Pt > Pd > Ru > Rh and Sn/Ir ≈ Sn/Ru > Sn/Rh ≈ Sn/Pt > Sn/Pd, respectively. The electrolysis of nitrite for 5 h was carried out on each electrode in 0.1 M HClO₄ at −0.2 V. The conversion of nitrite increased due to the Sn modification (4–27% conversion). The highest N₂ selectivity (53%) was obtained using the unmodified Pt electrode. Sn was not effective for the N₂ selectivity.     

Application of surfactant modified zeolite membrane electrode towards potentiometric determination of perchlorate

Potentiometric electrodes based on the incorporation of surfactant-modified zeolite Y (SMZ) particles into poly vinyl chloride (PVC) membranes were described. The electrode characteristics were evaluated regarding the response towards perchlorate ions. PVC membranes plasticized with dioctyl phthalate and without lipophilic additives (co-exchanger) are used throughout this study. The influence of membrane composition on the electrode response was studied. The electrode exhibited a Nernstian response towards perchlorate in the concentration range of 7.9 × 10⁻⁶–8.0 × 10⁻² M with a slope of 59.7 ± 0.9 mV per decade of perchlorate concentration with a working pH range of 1.7–9.5 with a fast response time of ≤10 s. The lower and upper detection limits were 4.07 × 10⁻⁷ and 0.13 M, respectively. The electrode response to perchlorate remains constant in the temperature range of 20–40 °C and in the presence of 2.5 × 10⁻⁶–1 × 10⁻² M NaNO₃. The selectivity coefficients for perchlorate anion as test species with respect to other anions were determined. The proposed modified zeolite-PVC electrode can be used for at least 30 days without any considerable divergence in potential. It was applied as indicator electrode in water samples with satisfactory results. The results of this study and our previous work show HDTMA plays different roles according to the zeolite type and matrix, as HDTMA-zeolite Y in a carbon paste matrix showed a good Nernstian behavior towards phosphate anion.     

Facile growth of flower-like Au nanocrystals and electroanalysis of biomolecules

Growth of flower-like Au nanocrystals at room temperature on a conducting support and electroanalysis of biomolecules are described. The Au nanocrystals are grown by seed-mediated growth approach using electrochemically deposited Au nanoseeds (nAuS) without any template or surfactants. The flower-like nanocrystals (nAuF) have the size ranging from 75 to 350 nm. XRD profile of nAuF reveals the existence of (1 1 1), (2 0 0) and (3 1 1) planes, corresponding to the face centered cubic lattice of Au. The nAuF on the electrode surface have significantly large surface area of 0.354 ± 0.02 cm². The electroanalysis of biomolecules such as ascorbic acid (AA), dehydroascorbic acid (DHA), dopamine (DA) and reduced nicotinamide adenine dinucleotide (NADH) is performed using nAuF electrode. The nanocrystals on the electrode facilitate the oxidation of these bioanalytes; decrease in the overpotential and enhancement in the peak current is observed. Unlike the bulk Au electrode, nAuF electrode displays unique inverted ‘V’ shape voltammogram for NADH and DHA. Oxidation of AA occurs in two steps and two voltammetric peaks are obtained for AA in neutral and alkaline pH. Increase in the peak current and decrease in peak-to-peak separation with respect to the unmodified electrode are obtained for DA on nAuF electrode. The nAuF electrode shows high sensitivity, stability and linear response for a wide concentration range towards these analytes. The high sensitivity is ascribed to the ensemble behavior of the nAuF electrode.     

A differential pulse voltammetric method for simultaneous determination of ascorbic acid,dopamine, and uric acid using poly (3-(5-chloro-2-hydroxyphenylazo)-4,5-dihydroxynaphthalene-2,7-disulfonic acid) film modified glassy carbon electrode

A stable modified glassy carbon electrode based on the poly 3-(5-chloro-2-hydroxyphenylazo)-4,5-dihydroxynaphthalene-2,7-disulfonic acid (CDDA) film was prepared by electrochemical polymerization technique to investigate its electrochemical behavior by cyclic voltammetry. The properties of the electrodeposited films, during preparation under different conditions, and their stability were examined. The homogeneous rate constant, k_s, for the electron transfer between CDDA and glassy carbon electrode was calculated as 5.25(±0.20) × 10² cm s⁻¹. The modified electrode showed electrocatalytic activity toward ascorbic acid (AA), dopamine (DA), and uric acid (UA) oxidation in a buffer solution (pH 4.0) with a diminution of their overpotential of about 0.12, 0.35, and 0.50 V for AA, DA, and UA, respectively. An increase could also be observed in their peak currents. The modified glassy carbon electrode was applied to the electrocatalytic oxidation of DA, AA, and UA, which resolved the overlapping of the anodic peaks of DA, AA, and UA into three well-defined voltammetric peaks in differential pulse voltammetry (DPV). This modified electrode was quite effective not only for detecting DA, AA, and UA, but also for simultaneous determination of these species in a mixture. The separation of the oxidation peak potentials for ascorbic acid–dopamine and dopamine–uric acid were about 0.16 V and 0.17 V, respectively. The final DPV peaks potential of AA, DA and UA were 0.28, 0.44, and 0.61 V, respectively. The calibration curves for DA, AA, and UA were linear for a wide range of concentrations of each species including 5.0–240 μmol L⁻¹ AA, 5.0–280 μmol L⁻¹ DA, and 0.1–18.0 μmol L⁻¹ UA. Detection limits of 1.43 μmol L⁻¹ AA, 0.29 μmol L⁻¹ DA and 0.016 μmol L⁻¹ UA were observed at pH 4. Interference studies showed that the modified electrode exhibits excellent selectivity toward AA, DA, and UA.     

Electrocatalytic oxidation of hydrazine using glassy carbon electrode modified with carbon nanotube and terpyridine manganese(II) complex

Here, we report a simple and extremely effective method to modify a glassy carbon (GC) electrode with carbon nanotubes (CNTs) and [Mn(CH₃COO)(CH₃OH)₂(pyterpy)]ClO₄, (pyterpy = 4′-(4-pyridyl)-2,2′:6′,2′′-terpyridine) complex. The kinetics of the reaction between, the terpyridine manganese(II) complex, mediator and hydrazine has been characterized using cyclic voltammetry and rotating disk electrode voltammetry. The catalytic currents were proportional to the concentration of hydrazine giving rise to calibration curves characterized by two linear segments. The linear segment over the concentration range of 1.00 × 10⁻³–1.05 mM could be used with analytical purposes to determination of hydrazine with a detection limit of 0.50 μM and a sensitivity of 0.038 μA/μM. The heterogeneous rate constant, k′ for the oxidation of hydrazine at the surface of the modified electrode was determined by rotating disk electrode voltammetry using the Koutecky–Levich plot. The transfer coefficient (α) for electrocatalytic oxidation of hydrazine and the diffusion coefficient of this substance under the experimental conditions were also investigated. The resulting modified electrode retains its initial response for at least one month if stored dry in air.     

Covalently immobilized biosensor based on gold nanoparticles modified TiO2 nanotube arrays

Highly ordered TiO₂ nanotube array with inner diameter of 120 nm was formed by anodizing titanium foils and was further modified for enzyme immobilization and biosensing. AuNPs sized in 8–12 nm were uniformly electrodeposited on TiO₂ nanotube arrays by pulsed method. Glucose oxidase (GOD) was covalently immobilized on the surface of gold nanoparticles (AuNPs) modified TiO₂ nanotube array electrode for the first time. Results demonstrate that the modified TiO₂ nanotube array electrode exhibits good electrocatalytic performance and high sensitivity without any electron mediator. The covalently fabricated glucose biosensor shows higher immobilized ratio of GOD, good reproducibility and stability. These indicate AuNPs modified TiO₂ nanotube array is an attractive material for using in the fabrication of biosensors because of its excellent biocompatibility, high specific surface area, unique nanostructure, and effective immobilization of biomolecules. This facile modification approach could be extended to prepare various TiO₂ nanotube array based biosensors.     

Comparison of the stabilities and activities of Pt–Ru/C and Pt3–Sn/C electrocatalysts synthesized by the polyol method for methanol electro-oxidation reaction

Carbon-supported Pt, Pt–Ru, Pt₃–Sn electrocatalysts have been synthesized by a modified polyol method. Energy dispersive spectroscopic (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopic (XPS) analyses reveal that the as-prepared samples are composed of mainly Pt and RuO₂ or SnO₂ and the formation of alloys is found only after heat-treatment at 200 °C in a flowing 10% H₂–90% Ar atmosphere. The activity and durability for the methanol electro-oxidation reaction (MOR) have been evaluated by accelerated durability test (ADT) carried out by scanning the electrode potential for extended number of cycles in the potential ranges of 0.02–0.6, 0.02–0.8, and 0.02–1.2 V vs. NHE. Regardless of heat-treatment, the initial activity for MOR decreases in the order Pt–Ru/C > Pt₃–Sn/C > Pt/C and the durability decreases in the order Pt/C > Pt₃–Sn/C > Pt–Ru/C. During the ADT of the as-prepared Pt–Ru/C and Pt₃–Sn/C, no detectable amount of dissolved Sn ions was found in the electrolyte solution, while almost 40% of Ru could be found in the electrolyte solution after ADT between 0.02 and 1.2 V vs. NHE. With MOR activity comparable to and durability better than that of Pt–Ru, the Pt-Sn based catalysts offer the potential to be employed as anode catalysts in direct methanol fuel cells.     

Electrocatalytic oxidation of some amino acids on a cobalt hydroxide nanoparticles modified glassy carbon electrode

In this study we investigated the electrocatalytic oxidation of cysteine, cystine, N-acetyl cysteine, and methionine on cobalt hydroxide nanoparticles modified glassy carbon electrode in alkaline solution. Different electrochemical techniques such as cyclic voltammetry, chronoamperometry and steady-state polarization were used to track the oxidation process and its kinetics. From voltammetric studies we concluded that in the presence of amino acids the anodic peak current of Co(IV) species increased, followed by a decrease in the corresponding cathodic current peak. This indicates that amino acids were oxidized on the redox mediator which was immobilized on the electrode surface via an electrocatalytic mechanism. Using Laviron’s equation, the values of α_s and k_s for the immobilized redox species were determined as α_s,a = 0.63, α_s,c = 0.38 and k_s = 0.28 s⁻¹, respectively. The catalytic rate constants, the electron transfer coefficients and the diffusion coefficients involved in the electrocatalytic oxidation of amino acids were determined.     

Time-differential frequency response of electrochemical quartz crystal electrode during the dissolution and deposition processes of Au in H2SO4 solution containing chloride ion

Time-differentiation of the frequency response observed with electrochemical quartz crystal microbalance (EQCM) was applied for the analysis of the electrode processes for the Au electro-dissolution and deposition in acidic aqueous solution containing free chloride ion (Cl⁻). Evaluation for the values of the apparent equivalent molar mass per second proved the generation of the Au(I) species during the oxidation and reduction reactions of Au electrode in the presence of Cl⁻ at a level of 10 mM, which has not been reported so far. It was found that the electron-transfer reactions composed of Au(0), Au(I) and Au(III) species are participated in the overall Au electro-dissolution and deposition reactions in the applied potential range from −0.10 to 1.50 V (vs. Ag/AgCl).     

Electrodeposition of Au from [EMIm][TFSA] room-temperature ionic liquid: An electrochemical and Surface-Enhanced Raman Spectroscopy study

In this paper we report in situ Surface-Enhanced Raman Scattering (SERS) experiments carried out during the electrochemical deposition of gold from Au(I) cyanocomplexes in the room-temperature ionic liquid (RTIL) 1-ethyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl) amide ([EMIm][TFSA]). The obtained SERS spectra indicated the co-adsorption of CN⁻ and both anions and cations of the RTIL in the range from −1.8 to +0.3 V vs. an Au quasi-reference electrode (QRE). The surface CN⁻ peak exhibits a Stark tuning of ca. 28 cm⁻¹ V⁻¹. The oxidation of CN⁻ to OCN⁻ was observed at potentials more anodic than 0.3 V. The study was complemented by cyclic voltammetry, pinpointing RTIL reactivity at an Au electrode as well as CN⁻ adsorption effects and Au(I) reduction. SEM observations allowed to identify the conditions for the achievement of continuous Au films as well as the morphological peculiarities of Au electrodeposited from [EMIm][TFSA]. XPS measurements proved that no RTIL is incorporated into the Au film, under the investigated conditions.