Nucleation and Crystal Growth of Pt Electrodeposition on Poly Crystal Au Microdisc Electrode

Authors

Zhi-yong TAO, College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072, China
Pei-fang LIU, College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072, ChinaFollow

Corresponding Author

Pei-fang LIU(jtlu@whu.edu.cn)

Abstract

Based on the Fleischmann's model of nucleation and crystal growth for electrodeposition combined with the Barradas-Bosco's adsorption-nucleation model for electrochemical phase formation, the chronoamperometry was well fitted for Pt deposition on polycrystalline Au micro disc electrodes (30 μm in diameter) in different H₂PtCl₆ concentrations at different over-potentials. The initial stage of Pt deposition in dilute H₂PtCl₆ could be interpreted by the model of H₂PtCl₆ adsorption combined with instantaneous nucleation and two-dimensional cylindrical growth. The rate constant of the two-dimensional growth increased linearly with overpotential. Then the deposit grew layer by layer and the rate constant increased non-linearly with overpotential. In contrast to the situation in dilute solutions, Pt deposition in higher H₂PtCl₆ concentrations was found to follow the mechanism of adsorption-instantaneous nucleation and three-dimensional cone growth.The rate constant of perpendicular growth k_perp appeared two orders of magnitude larger than that of parallel growth k_paraand increased linearly with overpotential. However, the k_para increased with overpotential in S shape. Both k_perpor k_para in concentrated solutions were larger than the growth rate constant in dilute solutions.

Keywords

Electrodeposition, Nucleation and crystal growth, Electrodeposition of Pt on Au, Microelectrodes

DOI Link

https://doi.org/10.61558/2993-074X.1575

Publication Date

2004-08-28

Online Available Date

2004-08-28

Revised Date

2004-04-13

Received Date

2004-01-20

Recommended Citation

Zhi-yong TAO, Pei-fang LIU. Nucleation and Crystal Growth of Pt Electrodeposition on Poly Crystal Au Microdisc Electrode[J]. Journal of Electrochemistry, 2004 , 10(3): 279-286.
DOI: 10.61558/2993-074X.1575
Available at: https://jelectrochem.xmu.edu.cn/journal/vol10/iss3/5