Browsing by Autor "Margarita Rivera"

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A Kinetic Study of Silver Electrodeposition Onto Pt Ultramicroelectrodes From Amoniacal Solutions
(Croatian Chemical Society, 2020) Jair A. Corona-Castro; Giaan Arturo Álvarez‐Romero; Margarita Rivera; José M. Sausedo-Solorio; Clara Hilda Rios-Reyes; Luis Humberto Mendoza-Huízar
A kinetic study of the Ag electrodeposition onto Pt ultramicroelectrodes of 10, 15 and 25 m of diameter from an aqueous solution containing AgNO3 1 mM + NH4NO3 0.1 M was conducted at overpotential conditions through potentiostatic studies. The analysis of the current density transients indicates the existence of two 2D nucleation and growth processes previous to the 3D nucleation and growth process.
AN ELECTROCHEMICAL STUDY OF THE COBALT ELECTRODEPOSITION ONTO A CARBON FIBER ULTRAMICROELECTRODE
(Sociedad Chilena de Química, 2022) Jair A. Corona-Castro; Giaan Arturo Álvarez‐Romero; Margarita Rivera; Clara Hilda Rios-Reyes; L.E. Bañuelos-García; Eduardo García Sánchez; Luis Humberto Mendoza-Huízar
A kinetic study of the cobalt electrodeposition onto a carbon fiber ultramicroelectrode of 11 m of diameter was conducted in overpotential conditions from an aqueous solution containing 0.01 M CoCl2 + 0.1 M NH4Cl. From the voltamperometric and chronoamperometric studies, it was found that the value of the diffusion coefficient is 1.2x10 -5 cm 2 s -1 . The analysis of the current density transients suggests that cobalt electrodeposition onto a carbon fiber electrode follows an instantaneous nucleation process controlled by spherical diffusion mass transport. Also, the number of active nucleation sites increases as the applied potential decreases.
Influence of Bitartrate Ion Concentration in the Copper Electrodeposition Onto a Polycrystalline Gold Electrode
(Croatian Chemical Society, 2021) M. Hernández; Giaan Arturo Álvarez‐Romero; Margarita Rivera; Simplicio González–Montiel; Clara Hilda Rios-Reyes; Luis Humberto Mendoza-Huízar
In the present work, the influence of the concentration of bitartrate ions (HT) on the copper electrodeposition process was analyzed. The study was carried out from an aqueous solution containing 0.001 M of CuX (where X = (NO3 -)2 ,(Cl -)2, SO4 2-) and x M KHT (where x = 0.005 M, 0.01 M, and 0.015 M). From voltammetric and chronoamperometric studies, the results indicate that copper electrodeposition is a diffusioncontrolled process. The current density transients were well described through a kinetic mechanism involving capacitive and faradaic contributions. The diffusion coefficient values of Cu 1+ and Cu 2+ result to be similar at the different concentration values of potassium bitartrate used in this work.