Cyclic voltammetric studies on sphalerite electrodes

Cyclic voItammetric studies on sphlarite compact electrodes containing 30% Graphite and 10% pitch and carbon paste electrodes have been carried out in sulphuric acid of concentration 0.5N, l.ON and 2.0N at different scan rates. The open circuit voltage varies from 200 to 300 mV. It has been observed that the dissolution current increases with acid concentration and scan rate. The peak current also increases slightly if the initial potential is changed from 0 to -0.4 V. The cyclicvoItammogram shows the oxidation of ZnS, the product, sulphur in the forward cycle and the reduction of the oxidation product in the reverse (cathodic) cycle. The peak potential shifts anodically, as the scan rate is increased; but shifts to less anodic potential with the rise in the concentration of the acid.