The influence of solution composition on lead, cadmium and thallium underpotential deposition on (111) oriented silver single crystal surfaces

doi:10.1016/0022-0728(90)80037-7

Journal of Electroanalytical Chemistry and Interfacial Electrochemistry

Volume 288, Issues 1–2, 10 August 1990, Pages 229-243

https://doi.org/10.1016/0022-0728(90)80037-7 Get rights and content

Abstract

The influence of solution composition on the process of lead, cadmium and thallium UPD on (111) oriented silver single crystal surfaces has been investigated by using linear sweep voltammetry and differential capacity measurements. It is shown that the Y'-E curves can be used qualitatively as a criterion for the occurrence of partial charge transfer reactions in the double layer region and the commencement of the faradaic reaction of UPD. The C-E curves obtained in the presence and in the absence of depositing metal cations can give useful information about the nature of species present in the solution and adsorbed onto the substrate surface. It is also demonstrated that the presence of different complexes of cations investigated and the kinetics of their reduction can be responsible for a change in the UPD voltammograms.

References (21)

H. Gerischer et al.
Surf. Sci.
(1974)
M. Klimineck et al.
Electrochim. Acta
(1982)
K. Takayanagy et al.
Surf. Sci.
(1980)
A. Bewick et al.
Faraday Symp. Chem. Soc.
(1978)
A. Bewick et al.
Faraday Symp. Chem. Soc.
(1978)
J.N. Jovićevié et al.
Electrochim. Acta
(1984)
V.D. Jović et al.
Electrochim. Acta
(1985)
J.N. Jovićević
(1978)
I.L. Cooper et al.
Electrochim. Acta
(1984)
N. Pangarov
Electrochim. Acta
(1983)
D.M. Kolb

There are more references available in the full text version of this article.

Cited by (24)

Uncovering the nature of electroactive sites in nano architectured dendritic Bi for highly efficient CO<inf>2</inf> electroreduction to formate
2020, Applied Catalysis B: Environmental
Citation Excerpt :
The EASA of Biden covered with various amounts of Pb was then measured and the activity for the ERC was assessed again. It is known from the Pb underpotential deposition (UPD) literature that anions in the plating solution can be strongly adsorbed on defects present at an electrode surface, thereby preventing Pb deposition at these high energy sites and favoring it at low index facets and defect-free sites. [45–47] As seen in Fig. 6a, the percent of Bi EASA loss varies linearly with the number Pb deposition cycle.
Porous electrodes based on Bismuth dendrites (Bi_den) were fabricated using Dynamic Hydrogen Bubbling Templates (DHBT). Direct visualization of surface-active sites with the help of advanced transmission electron microscopic (TEM) imaging reveals the presence of abundant defect structures and high-index faceting, while selective decoration of low-index facets of Bi dendrites indicate that they are the most active Bi surface sites. The fabricated electrodes show high selectivity toward CO₂ electroreduction to formate synthesis, with a 98% Faradaic Efficiency and a current density of 18.8 mA cm⁻² (344 μmol cm⁻² h^–1) at –0.82 V vs RHE, which is only 600 mV more negative than the thermodynamic potential. Both the dendritic structure and CO₂ electrolysis performances are remarkably stable over long electrolysis periods (∼15 h). Additionally, large production rates (1.63 mmol cm⁻² h^–1 or 95 mA cm⁻² at –0.82 V vs RHE) without significant penalty on the formate Faradaic Efficiency (92 ± 4%) was achieved in high-pressure flow cell, where the CO₂ flux is greatly enhanced compare to an H-cell. The work thus outlines an effective strategy for the development of dendritic materials with superior performance toward electroreduction of CO₂.
DFT study of the formation of Cd-Ag surface alloys on Ag surfaces
2016, Computational Materials Science
Citation Excerpt :
The UPD process occurs when the interaction between the adsorbed and substrate atoms is stronger than the adsorbed atoms interaction between themselves; then it is feasible, in principle, that a site exchange between the adsorbate and substrate atoms occurs after adsorption, resulting in the formation of surface alloys [1]. The Cd/Ag system has been extensively studied experimentally by electrochemical techniques and by in-situ STM, analyzing the Cd UPD on Ag(1 1 1), Ag(1 0 0) and polycrystalline silver [13–16]. Cd UPD deposition on Ag(1 1 1) and Ag(1 0 0) occurs epitaxially, starting with the deposition of expanded monolayers, which then leads to compact monolayers by a first order phase transition [1,15,17].
We investigate the feasibility of forming a surface alloy between Ag and Cd on Ag surfaces, employing Density Functional Theory calculations. Six layers slabs are used to model surface alloy systems. Adsorption energies for Cd atoms and a monolayer on Ag(1 1 1) and Ag(1 0 0) surfaces are calculated, and compared with surface alloy formation energies, verifying the energetic preference of Ag and Cd to stay in alloyed form on the surface, as found in different electrochemical experiences for this system. This means that there is an electronic effect which favors this type of phenomenon. An analysis of the charge densities and projected densities of states for the different structures proposed is also performed.
Electrochemical synthesis of Cd-Ag bimetallic particles and the involved alloy formation
2014, Journal of Electroanalytical Chemistry
Citation Excerpt :
Most relevant in this study is the UPD of Cd on Ag single crystals electrodes. Underpotential deposition of Cd on Ag single crystals was extensively studied by STM and electrochemical techniques [6–10]. Also the formation of Ag/Cd films onto Au (1 1 1) substrates [11] has been reported in the literature due to their valuable catalytic properties for the electroreduction of nitrate and nitrite ions, being both contaminants of effluents.
The formation of bimetallic Cd–Ag nanoparticles on vitreous carbon (VC) and the involved alloy formation have been studied by conventional electrochemical techniques and ex-situ atomic force microscopy (AFM). Both metals were deposited by sequential electrodeposition using single potentiostatic pulses. The AFM images of Ag deposits showed small differently sized Ag nanocrystallites uniformly distributed over the VC-substrate. This modified substrate was immersed in an electrolyte solution containing Cd²⁺ ions and bimetallic Cd–Ag particles were prepared by underpotential deposition (UPD) of Cd. The alloy formation phenomena observed previously during Cd UPD on massive Ag electrodes were found also in the case of Cd UPD on Ag nanoparticles. The desorption spectra in the system Cd/Ag (nanoparticles)/VC employing different polarization times, showed three desorption peaks associated with the dissolution of the Cd OPD and UPD deposits and an Ag–Cd alloy formed at low underpotentials, respectively. The electrochemical behavior of the bimetallic system was also studied applying other polarization routine designed for this purpose.
Underpotential deposition of Cd on Ag(1 1 1): An in situ STM study
2005, Surface Science
The kinetics and mechanism of Cd underpotential deposition (UPD) and involved surface alloy formation processes in the system Ag(1 1 1)/Cd²⁺, ${SO}_{4}^{2 -}$ , are studied by means of combined electrochemical measurements and in situ scanning tunneling microscopy (STM). The results show that the UPD process starts with a formation of an expanded (diluted) adlayer with a superlattice structure Ag(1 1 1)- $(\sqrt{3} \times \sqrt{19}) R 23.4 °$ . In the underpotential range 50 mV < ΔE < 80 mV this adlayer transforms to a condensed close packed Cd monolayer via a first order phase transition. At long polarization times the condensed monolayer undergoes structural changes involving place exchange processes between Cd atoms and surface Ag atoms. A formation of a second Cd monolayer and a significant Ag–Cd surface alloying take place at lower underpotentials (ΔE < 50 mV). The kinetics of surface alloying are analyzed on the basis of a recently proposed diffusion model including a relatively fast initial formation of a very thin surface alloy film and a subsequent slow alloy growth controlled by solid state diffusion. The anodic dealloying results in an appearance of monatomically deep pits, which disappear quickly at relatively high underpotentials (ΔE > 550 mV) indicating a high mobility of surface Ag atoms.
Underpotential deposition of cadmium onto (111) face of silver from chloride containing solution
2002, Electrochimica Acta
The underpotential deposition (UPD) of cadmium and Ag–Cd alloy formation on the (111) face of silver in chloride containing solutions were investigated by cyclic voltammetry and the potentiostatic pulse technique. It was shown that the UPD of cadmium commences at about −400 mV versus SCE (300 mV vs. Cd²⁺/Cd) with the formation of ordered structure of the type ( $3 x 3$ )R30°. Chloride adatoms, which are adsorbed on the silver substrate when UPD of Cd starts, do not desorb. They become replaced by Cd adatoms and remain adsorbed and discharged on top of a Cd layer. At potentials close to the reversible potential of Cd alloying of Ag with Cd takes place, being expressed by two sharp cathodic peaks on the voltammograms.
Electrochemical evidence of the adsorption of alkanethiols on two sites on Ag(111)
2000, Journal of Electroanalytical Chemistry
Citation Excerpt :
The voltammogram of the lead upd on Ag(111), a two-electron process, is shown in Fig. 1. It is identical to that in previous reports [38,39]. For the calculation of the roughness factor, we used the nearest neighbor distance between the lead atoms of 3.415 Å suggested by White et al. [40].
We present spectroscopic and electrochemical results consistent with the adsorption of alkanethiols on two sites and the formation of a very densely packed, stable, monolayer on Ag(111). A surface coverage of alkanethiols of 8.5 (±0.4)×10⁻¹⁰ mol cm⁻² was calculated from the charge associated with the reduction of a monolayer of alkanethiols. Alkanethiol modified Ag(111) electrodes were found to have lower capacitances than the alkanethiol modified Au(111) electrodes. The lower capacitances are due to the higher surface concentration of alkanethiols on Ag(111). The very low intensity of the methylene CH stretching bands of alkanethiols with alkane chains of four to nine carbons chemisorbed on Ag(111) suggests a vertical orientation of all-trans alkane chains. No vibrational evidence of oxidation of the chemisorbed alkanethiols was found after exposure to air for up to 6 weeks. A fine structure consisting of two current peaks was observed in all cyclic voltammograms of the reduction of chemisorbed alkanethiols. This revealed that the reduction of chemisorbed alkanethiols occurs in two steps on Ag(111). Chronoamperometric measurements also support a two-step reductive desorption of alkanethiols. The high surface concentration of alkanethiols and the orientation of the alkane chains suggest that the fine structure in the voltammograms is due to the reduction of the alkanethiols from two adsorption sites.

View all citing articles on Scopus

View full text

The influence of solution composition on lead, cadmium and thallium underpotential deposition on (111) oriented silver single crystal surfaces

Abstract

Surf. Sci.

Electrochim. Acta

Surf. Sci.

Faraday Symp. Chem. Soc.

Faraday Symp. Chem. Soc.

Electrochim. Acta

Electrochim. Acta

Electrochim. Acta

Electrochim. Acta