Batric Pesic
University of Idaho, USA
Title: Electrodeposition of nickel on glassy carbon electrode – The rotating disk study
Biography
Biography: Batric Pesic
Abstract
Electrodeposition of nickel was studied by using rotating disk technique. The electrode substrate was glassy carbon disk cut from a glassy carbon wafer produced by Toshiba. The disk was mounted on a rotation speed controlled rotator made by IBM Instruments. The electrochemical deposition was studied from nickel ammonium sulfate solutions of different concentrations and pH, as the reaction parameters. The electrochemical techniques used were cyclic voltammetry, linear sweep voltammetry, and chronoamperometry. The key feature of this study is that amount of electrodeposited disk was determined by two methods. These are charge passed and amount of nickel deposited at particular time intervals, such as 15, 30 and 60 seconds. Charge was determined by using a coulometer wired in line with the working electrode. Nickel deposited was determined by dissolution in nitric acid and analysis by atomic absorption. Both types of data were used in Levich equation for determination of kinetic parameters, such as reaction order, activation energy, etc. For example, it was found that electrodeposition of nickel is of the first order, and that the activation energy was only 2.7 kcal/mol, indicating a mass transfer controlled reaction. The current efficiency was a function of concentration, increasing with the increase of nickel concentration. Morphology of electrodeposit was very smooth as confirmed by atomic force microscopy.