Application of carbon fiber microelectrodes in electrochemical investigations

Abstract

In this work, the electrocrystallization of nickel from Ni2+ -acidic bath has been investigated using an assembly of carbon fiber microelectrodes, consisting of single and multi microdics randomly distributed inside the matrix of a non-conducting polymer. The microdiscs were far enough apart that the crystals could not interact, thus limiting the total observed current density to a linear superposition of the current densities from each crystal considered independently. The current-time transient response was quantitatively evaluated using the Scharifker and Hills' nucleation model. The high rate of nucleation after a rapid increase in the overpotential was discussed in relation to the physical model for three-dimensional (3D) nucleation with diffusion-controlled growth. Excellent agreement between the experimental results and the theoretical curve for 3D progressive nucleation was obtained.