Effect of sodium lauryl sulphate (SLS) on nickel electrowinning from acidic sulphate solutions

The effect of sodium lauryl sulphate (SLS) on the cathodic current efficiency (CE), surface morphology, crystallographic orientations and polarization behaviour of the stainless steel cathode during nickel electrowinning from acidic sulphate solutions was investigated. The results indicated that SLS did not have a significant effect on the cathodic current efficiency. However, noticeable changes in the surface morphology and deposit quality were observed. Cyclic and linear sweep voltammetric studies revealed that an increase in SLS concentration from 2 to 40 mg dm(-3) increased the cathodic potential and shifted the nucleation overpotential (NOP) towards more negative values which was also reflected in the decrease in the rate of electron transfer i.e. i(0) values obtained on both the stainless steel and nickel substrates. The presence of SLS did not change the fcc structure of the electrodeposited nickel but affected the peak intensities of the various crystal planes. (C) 2009 Elsevier B.V. All rights reserved.