Catalytic effect of l-proline on the reduction of Ni(II) ions during nickel electrodeposition from a Watts-type nickel bath
By Boraei, N. F. El; Ibrahim, M. A. M.
Published in Surface and Coatings Technology
2018
Abstract
Many chemical entities have been proposed as additives to enhance the properties and structure of electrodeposited nickel. In this work, considerable improvements have been found by using l-proline as a complexing agent in a Watts-type nickel bath. This study determined the influence of l-proline concentrations on the cathodic efficiency, cathodic polarization, anodic linear stripping voltammetry, current-time transients, macrothrowing power and Wagner number. The presence of l-proline leads to a great shift in the polarization curve and the deposition potential towards more noble potentials, indicating the catalytic effect of l-proline on the reduction of Ni(II) ions. The kinetic data confirmed that the exchange current density is greatly enhanced with increasing l-proline concentration. The Tafel slopes in the presence of l-proline are higher (141