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

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

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

The role of temperature in copper electrocrystallization in ammoniachloride solutions

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

Synthesis and crystal structures of cis-palladium(II) and cis-platinum(II) complexes containing di...

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

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

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

Synthesis, Characterization and Catalytic Activity of Supported NiMo Catalysts

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