Detailed underpotential deposition of copper on gold(III) in aqueous solutions

Hachiya, Toshinori; Honbo, Hidetoshi; Itaya, Kingo

doi:10.1016/0022-0728(91)80076-3

Cited by 277 publications

(186 citation statements)

References 25 publications

Supporting

Mentioning

161

Contrasting

Unclassified

Order By: Relevance

“…Coverage of Pt deposits was controlled by use of Cu underpotential deposition (UPD) and manipulation of the emersion potential. Cu UPD is a well-studied process and is known to proceed in two waves, with the first wave depositing 2/3 of a monolayer and the second wave completing the full monolayer coverage [11]. By removing samples from the Cu bath at a potential between these two deposition waves, we were able to limit the Cu deposit to *0.6ML per iteration.…”

Section: Methodsmentioning

confidence: 99%

Near Surface Phase Transition of Solute Derived Pt Monolayers

et al. 2013

View full text Add to dashboard Cite

As the loadings of precious metals in surfacechemical systems continue to decrease for photo-and electro-catalysts for energy and environmental applications, the study of near-surface electronic and atomic structure in functional materials becomes critically important. Extremely small quantities of active elements, whether grown as clusters or ultrathin films, exhibit changes in catalytic activity that arise from both size effects and electron-transfer effects. These size and transfer effects can be related to increased propensity for oxidation of the metallic deposit, as well as to various changes in electrochemical performance such as durability or required overpotential for a given reaction. This work establishes a minimum threshold for Pt loading beyond which bulk-type electronic behavior may be expected. By iteratively growing atomic monolayers and multilayers using selflimited electrodeposition and studying these films using core-electron spectroscopy (X-ray absorption and X-ray photoelectron spectroscopy), electrochemical methods and DFT-based computations the fundamental interactions that govern oxidation state and electron transfer near the surface of a Pt-Au bimetallic system have been explored. It has been shown that the Pt-Au system exhibits increased tendency for the Pt layer to remain cationic below a minimum threshold film thickness of two monolayers. At monodispersed levels of submonolayer coverage Pt exhibits deviated electronic structure, reactivity, and metal stability compared to films in excess of this minimum threshold thickness. At three monolayers Pt is thick enough to avoid the preference for cationicity and the resulting higher rates of metal dissolution, but thin enough to benefit from electron transfers from Au that assist in lowering the overpotentials for CO oxidation. This study shows the efficacy of a concerted method for the investigation of near-surface phenomena in multicomponent systems. By combining electrochemical and vacuum studies of solutederived samples with advanced computational techniques, a multifaceted understanding of these architectures has been achieved.

show abstract

Section: Methodsmentioning

confidence: 99%

Near Surface Phase Transition of Solute Derived Pt Monolayers

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Similar CVs were reported in previous studies using Au single-crystal surfaces 6,21 and polycrystalline Au. [7][8][9][10]26 The reductive deposition of Te from TeO 2 is known to occur by the following four-electron reduction process: [11][12][13][14][15][16][35][36][37] Figure 2 shows the p-in/ p-out SH rotational anisotropy patterns of the Au(111) electrode biased at (a) +800 mV and (b) +150 mV in 0.1 M HClO 4 . Although both patterns showed the 3-fold symmetry with the SH intensity maxima at the azimuthal angles of 60°, 180°, and 300°, the SH intensities at +150 mV were smaller than those at +800 mV.…”

Section: Methodsmentioning

confidence: 99%

“…[1][2][3] Recently, upd has been used as a common method to prepare structurally welldefined atomic layers in the electrochemical environment. [4][5][6][7][8][9][10] The electrochemical atomic layer epitaxy (ECALE), which is an analogue of ALE in the gas phase of binary materials, is achieved by sequential upd of two different elements. Stickney and his co-workers used this technique to prepare CdTe, CdS, CdSe, and GaAs films on gold electrode surfaces.…”

Section: Introductionmentioning

confidence: 99%

In Situ Optical Second Harmonic Rotational Anisotropy Measurements of an Au(111) Electrode during Electrochemical Deposition of Tellurium

1998

View full text Add to dashboard Cite

The electrodeposition of Te on a single-crystalline Au(111) electrode was studied with 1064-nm-excited SH rotational anisotropy measurements. The SH rotational anisotropy was significantly changed with the first underpotential deposition (upd) of Te, and the bulk Te deposition attenuated the anisotropic character of the overall surface symmetry. The change in the SH rotational anisotropy during the first upd of Te was examined using two different models. The first model considered only the contribution of the Au(111) surface to the SHG response, while the second one took into account the contributions of both the Au(111) substrate and the adsorbed Te layer. In the former case, the change in the SH rotational anisotropy can be explained by considering the quenching of the nonlinear susceptibility of the Au(111) surface. The analysis based on the latter model resulted in a rotation angle of 608 for the adsorbed Te layer against the the Au(111) lattice. This value was not consistent with that expected from the adsorbate structure of the first upd layer of Te, i.e., ( 3× 3)R30°. Thus, the former model seems to be more appropriate to explain the present results. The SH rotational anisotropy measurement also suggests that the morphology became more isotropic after the bulk Te deposition.

show abstract

“…These UPD and OPD peaks are very similar to those previously reported. [2][3][4][6][7] Comparison to the cyclic voltammogram for the same process at pH 4 ( Figure 1) demonstrates several differences. At pH 1, the UPD peaks are broader than those recorded at pH 4.…”

Section: Copper Deposition Onto the Au(111) Electrode Surface Previomentioning

confidence: 99%

New Insights into Evaluation of Kinetic Parameters for Potentiostatic Metal Deposition with Underpotential and Overpotential Deposition Processes

2000

View full text Add to dashboard Cite

Kinetics of copper deposition onto an Au(111) surface from sulfuric acid electrolyte, was evaluated using potentiostatic current transients. Measurements were conducted employing a new and nontraditional method, with gold electrode completely free from copper deposit at the beginning of the potential step (i.e., deposition process). The current transients obtained clearly show partial contribution from copper underpotential deposition (UPD) and copper overpotential deposition (OPD) processes. Quantitative evaluation of experimental transients was performed with the recently developed method for theoretical transient computer simulation. Detailed analysis of the kinetic parameters shows that copper UPD could be characterized as a two-dimensional nucleation and growth limited by the lattice incorporation (2D-LI) process and copper OPD as a three-dimensional nucleation process limited by diffusion-controlled growth (3D-DC). The UPD seems to be an inevitable part of the deposition process and takes place prior to OPD, regardless of the potential applied. Therefore, UPD should be treated as an early stage of the deposition process. Furthermore, our results show that the kinetics differs depending on whether deposition is initiated from a clean, bare Au(111) surface or from a gold surface already coated with a copper UPD adlayer. This indicates the role of the UPD process and the UPD adlayer on the course of OPD. Differences observed in deposition kinetics between electrolytic baths at pH 2 and 4 were likely due to adsorption of different sulfate species (sulfate or bisulfate anions) on the copper-deposit-modified Au(111) substrate (UPD, epitaxial monolayer) or bulk deposit adlayer (OPD).

show abstract

Detailed underpotential deposition of copper on gold(III) in aqueous solutions

Cited by 277 publications

References 25 publications

Near Surface Phase Transition of Solute Derived Pt Monolayers

Near Surface Phase Transition of Solute Derived Pt Monolayers

In Situ Optical Second Harmonic Rotational Anisotropy Measurements of an Au(111) Electrode during Electrochemical Deposition of Tellurium

New Insights into Evaluation of Kinetic Parameters for Potentiostatic Metal Deposition with Underpotential and Overpotential Deposition Processes

Contact Info

Product

Resources

About