A study on cobalt electrodeposition onto a carbon steel electrode

The electrodeposition of cobalt on to a carbon steel working electrode was studied through the comparison between theoretical and experimental polarisation curves. The former was obtained using the Butler-Volmer equation with electrochemical parameters, such as Tafel slope values, exchange current densities, cathodic limit current densities and equilibrium potential values. The following results were obtained: the anodic region refers to the iron oxidation with a Tafel slope of about 0055 V decade(-1), which is near the theoretical value (0059 V decade-1); the experimental cathodic region represents the cobalt and hydrogen ion reduction; the limiting current density (-1 x 10(-3) to -1 x 10(-2) A cm(-2)) obtained was near the calculated value, -3.7 x 10(-3) A cm(-2).