Producción Científica Profesorado

Electrochemical kinetic study about cobalt electrodeposition onto GCE and HOPG substrates from sulfate sodium solutions



Mendoza Huizar, Luis Humberto

2010

Electrochemical Kinetic study about cobalt electrodeposition onto GCE and HOPG substrates from sulfate sodium solutions. C.H. Rios-Reyes, L.H. Mendoza-Huizar and M. Rivera, Journal of Solid State Electrochemistry. DOI 10.1007/s10008-009-0816-3. vol 14, 2010. pp. 659-668, ISSN: 1432-8488


Abstract


In the present work, we analyze the electrodeposition of cobalt by electrochemical techniques onto GCE (system I) and HOPG (system II) electrodes from sulfate solutions. Cyclic voltammetry and current transient measurements were used to obtain the nucleation and growth mechanism. The results clearly showed that electrodeposition of cobalt is a diffusion-controlled process with a typical 3D nucleation mechanism in both substrates. The average ?G calculated for the stable nucleus formation was 1.97×10?20J nuclei?1 and 3.58×10?20J nuclei?1 for system I and system II, respectively. The scanning electron microscope (SEM) images indicated similar nucleation and growth processes on GCE and HOPG substrates at same overpotential with a homogeneous disperse cobalt clusters. X-ray energy-dispersive spectroscopy (EDS) was performed in order to ensure that the clusters formed are cobalt. The nucleis size obtained was dependent of the overpotential applied; at lower overpotentials, the growth rate of the cobalt clusters diminishes when their number increases due to the strongly reduced concentration of cobalt ions because of their consumption by a larger number of growing particles. A theoretical quantum study employing PM6 method suggests that Na+ adsorbed deactivate the local surface occasionating the formation of disperse cobalt clusters on carbon electrodes.



Producto de Investigación




Artículos relacionados

Potentiometric behavior of graphite-epoxy electrochemical transducers towards anions, cations and pH...

Influence of the Crystallinity of the Substrate on Kinetic Parameters of Zinc Electrodeposition Proc...

Cobalt Electrodeposition Process from Electrolytic Baths based on CoSO4 and (NH4)2SO4. Influence of ...

Nucleation and growth of cobalt onto different substrates: Part I. Underpotential deposition onto a ...

A theoretical quantum study on the distribution of electrophilic and nucleophilic active sites on Ag...

Influence of the Cation Nature of the Sulphate Salt on the Electrochemical Synthesis of Sulfate-Dope...

Mercury Ions Removal from Aqueous Solution Using an Activated Composite Membrane

Cobalt electrodeposition on polycrystalline palladium. Influence of temperature on kinetic parameter...

Synthesis of Zn compounds derived from 1H-benzimidazol-2-ylmethanamine

Nucleation and Growth Kinetics of Electrodeposited Sulfate-Doped Polypyrrole: Determination of the D...