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Journal ArticleDOI

A comparative study of the early stages of mercury, cadmium, lead, silver and copper electrodeposition on columnar and smooth platinum electrodes

01 Jan 1996-Electrochimica Acta (Pergamon)-Vol. 41, Iss: 15, pp 2441-2449
TL;DR: In this article, the early stages of metal electrodeposition on columnar and smooth Pt substrates (S) were investigated in acid solutions applying potentiodynamic techniques and the relationship between the charge related to MS domains and ΔHs, the enthalpy of sublimation, and Tm, the melting temperature of M, were established.
About: This article is published in Electrochimica Acta.The article was published on 1996-01-01 and is currently open access. It has received 23 citations till now. The article focuses on the topics: Overlayer & Surface diffusion.

Summary (1 min read)

Jump to: [Metal] and [4. DISCUSSION]

Metal

  • (M = Cu, Ag, Hg, Cd and Pb) electrodeposition/anodic stripping voltammograms on CPtE (Figs 3-5 ) and smooth polycrystalline Pt (Fig. 6 ) were obtained under comparable conditions.
  • Different tips were used to discard occasional artifacts caused by the tip geometry.
  • For the sake of comparison, blank voltammograms were also systematically recorded (Fig. 7 ), particularly to establish possible ranges of potentials where interference of the M electrodeposition/anodic stripping reactions and the electrochemical reactions involving their own base solution constituents might occur.
  • The evaluation of the apparent charge density related to qMs from peak Ia requires the previous determination from the blank of the Oelectroadsorption charge.
  • In general, the voltammograms resulting from CPtE's run at a moderate or a fast potential scanning show that the M-S domain formation can be shifted negatively, overlapping partially the potential range where the formation of the M-M domains takes place, yielding a substrate which is either partially or completely covered by a deposit.

4. DISCUSSION

  • Where d2cJdx2 defines the change in the concentration gradient of M atoms in the x-direction at the smooth surface.
  • Thus, equation ( 5) makes it possible to estimate from experimental data (AZcrJAx2>,,, , the average value of d"c Jdx2 for the constant period of time involved in the voltammetric scan, taking D, values estimated from equations (l-3).
  • For every M these figures which are assembled in Table 3 , are useful to explore the possible Jo surface mobility mechanism.
  • Accordingly, at constant R, the lower D, the higher the d2c,/dx2 value and, hence, the smaller the average diffusion layer associated with M atom surface diffusion.
  • Pt rather than on columnar structured Pt.

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Citations
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Journal ArticleDOI
TL;DR: In this article, a modified potential step method is proposed to fix the energetic state of the electrode surface, which allows one to distinguish between the actual nucleation rate and the rate of appearance and disappearance of active sites, especially if the nucleation experiments are carried out using the standard pulse potentiostatic technique.

55 citations

Journal ArticleDOI
TL;DR: The spectroelectrochemical responses of mercury and lead on the ITO surface are characterized and optimized with respect to solution conditions, the potential excitation signals used for deposition and stripping, and wavelength for detection.
Abstract: The optical and electrochemical properties of metallic films on ITO surfaces resulting from deposition of copper and cadmium were monitored by stripping voltammetry-attenuated internal reflectance spectroscopy. The voltammetric or optical responses of both metals were examined with respect to solution conditions such as pH and presence of dissolved oxygen. The morphologies of these films were also examined using environmental scanning electron microscopy, and the microscopic electrodeposition patterns were found to influence the optical response. The wavelength dependence of the optical response of deposited copper was determined and compared with calculations; optimal performance was at 400 nm for copper. A linear calibration curve was obtained over a range of 1 × 10-7−1 × 10-4 M for copper and compared with that of cadmium. The simultaneous determination of cadmium and copper was demonstrated, and the mechanism of co-deposition is discussed.

44 citations

Journal ArticleDOI
TL;DR: In this paper, a polycrystalline Pt electrode was modified with p-block metals, such as indium, gallium, thallium, tin, lead, arsenic, antimony, bismuth, zinc, and cadmium, in both perchloric and sulfuric acid solution.
Abstract: Nitrate reduction was investigated on a polycrystalline Pt electrode modified with p‐block metals, such as indium, gallium, thallium, tin, lead, arsenic, antimony, bismuth, zinc, and cadmium, in both perchloric and sulfuric acid solution. Online electrochemical mass spectrometry was applied to detect volatile products on the electrode surface. In perchloric acid, tin, cadmium, indium, and gallium were found as active promoters for nitrate reduction, and N2O was detected as the main product for cadmium‐ and indium‐modified Pt electrode, whereas the tin‐modified electrode produced both NO and N2O. Lead cations inhibited nitrate reduction, but N2O was still formed selectively. In sulfuric acid, tin was an active promoter and showed the same coverage dependence for the product distribution as was reported previously for perchloric acid. Thallium performed similarly to germanium in that both metal cations only promoted nitrate reduction in sulfuric acid but not in perchloric acid, which could be attributed to their effect on disordering the bisulfate adsorption on Pt to recover active sites for nitrate reduction. Arsenic, antimony, and bismuth exhibited a similar effect on nitrate reduction on Pt sites in both acid electrolytes; they inhibited nitrate reduction on free Pt sites in the low‐potential range. Among the p‐block metals that were investigated, tin was the most active promoter for nitrate reduction, considering both the anion effect and the product distribution. DFT calculations were performed to gain insight into the promoting role of the two most active promoters, tin and indium.

38 citations

Journal ArticleDOI
TL;DR: In this article, the possible existence of H-subsurface states on Pt electrodes in acid solutions was studied using ex-situ scanning tunnelling microscopy (STM).

37 citations

Journal ArticleDOI
TL;DR: ASV-SECM can be used to detect and study induced dissolution not only at bulk metal surfaces but also on underpotential deposition layers, in this case Cd and Pb on Pt.
Abstract: We have developed a new imaging method for scanning electrochemical microscopy (SECM) employing fast-scan anodic stripping voltammetry (ASV) to provide sensitive and selective imaging of multiple chemical species at interfaces immersed in solution. A rapid cyclic voltammetry scan (100 V/s) is used along with a short preconcentration time (300–750 ms) to allow images to be acquired in a normal SECM time frame. A Hg−Pt film electrode is developed having an equivalent Hg thickness of 40 nm that has good sensitivity at short preconcentration times and also retains thin-film behavior with high-speed voltammetric stripping. Fast-scan anodic stripping currents are shown to be linear for 1–100 µM of Pb2+ and Cd2+ solutions using a preconcentration time of 300 ms. SECM images showing the presence of Pb2+ and Cd2+ at concentrations as low as 1 µM are presented. In addition, a single ASV-SECM image is shown to produce unique concentration maps indicating Cd2+ and Pb2+, generated in situ from a corroding sample, whil...

27 citations

References
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TL;DR: In this paper, the authors focus on topics at the forefront of electrochemical research, such as splitting water by electrolysis, splitting water with visible light, and the recent development of lithium batteries.
Abstract: This book focuses on topics at the forefront of electrochemical research. Splitting water by electrolysis; splitting water by visible light; the recent development of lithium batteries; theoretical approaches to intercalation; and fundamental concepts of electrode kinetics, particularly as applied to semiconductors are discussed. It is recommended for electrochemists, physical chemists, corrosion scientists, and those working in the fields of analytical chemistry, surface and colloid science, materials science, electrical engineering, and chemical engineering.

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01 Jan 1971

5,389 citations

Frequently Asked Questions (1)
Q1. What have the authors contributed in "A comparative study of the early stages of mercury, cadmium, lead, silver and copper electrodeposition on columnar and smooth platinum electrodes" ?

In this paper, the early stages of metal ( M ) electrodeposition on columnar and smooth Pt substrates ( S ) were investigated in acid solutions applying potentiodynamic techniques.