Producción Científica Profesorado

Nucleation and growth of cobalt onto different substrates: Part II. The upd-opd transition onto a gold electrode



Mendoza Huizar, Luis Humberto

2003

Nucleation and Growth of Cobalt onto different Substrates. Part II The upd-opd transition onto a gold electrode. L.H. Mendoza-Huizar, J. Roblesb, M. Palomar-Pardavé. http://dx.doi.org/10.1016/S0022-0728(03)00087-1


Abstract


A study of the electrochemical deposition of cobalt was carried out using electrochemical techniques. The formation kinetics and growth of cobalt nuclei onto a polycrystalline gold electrode were studied employing an aqueous 10?2 M CoCl2 1 M NH4Cl solution (pH 9.5). We obtain the potentiostatic jt plots when the potential step jumps from a potential value in the underpotential deposition zone to a final potential in the opd region. It was found that these current density transients can be described through a kinetic mechanism that involves three different contributions: (a) a Langmuir type adsorption process, (b) 2D diffusion-controlled instantaneous nucleation and (c) 3D nucleation limited by a mass transfer reaction. In order to describe the contribution due to 3D growth we test two different approaches by Scharifker and Mostany (J. Electroanal. Chem. 177 (1984) 13) and Heerman and Tarallo (J. Electroanal. Chem. 470 (1997) 70), the values of the experimental parameters A (nucleation rate constant), N0 (number of active nucleation sites) and D (diffusivity of the depositing ions) obtained in the two cases are quite close, however if the influence of the adsorption and 2D nucleation and growth processes is not considered, A and N0 are overestimated and underestimated, respectively.



Producto de Investigación




Artículos relacionados

Análisis del Comportamiento Presión-Temperatura en la Transición Isotrópico-Nemático del p-Azoxianis...

Do Spiroarsoranes Exhibit Polytopal Equilibrium in Solution?

Revisión de variables de diseño y condiciones de operación en la electrocoagulación

Kinetic study of the cobalt electrodeposition onto glassy carbon electrode from ammonium sulfate sol...

Theoretical and Experimental Study of Cobalt Nucleation and Growth onto Gold Substrate with Differen...

Hydrogen bond studies in substituted N-(2-hydroxyphenyl)--2-[(4-methylbenzenesulfonyl)amino]acetamid...

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

Magnetic transition phase diagram of cobalt clusters electrodeposited on HOPG: Experimental and micr...

Zinc Electrodeposition from Chloride Solutions onto Glassy Carbon Electrode

Bioacumulación y daños genotóxicos en Pez Cebra (Danio rerio) por arsénico en aguas de Zimapán, Hida...