CYCLIC VOLTAMMETRIC BEHAVIOR AND SOME SURFACE CHARACTERISTICS OF THE LEAD ELECTRODE IN AQUEOUS HCL SOLUTIONS

The positive linear sweep voltammograms of lead were investigated in 0.01-2.00 M aqueous HCl solutions. The results revealed the occurrence of one anodic current peak as the result of formation of a thin PbCl2 surface layer. Intensive study of the electrochemical behaviour of the lead electrode in 1.00 M HCI solution was carried out by cyclic voltammetry. The results indicated that the formation of PbCl2 is a reversible process controlled by diffusion of Cl- ions to the electrode surface. Controlling the voltammetric conditions enabled the building up of a relatively thick and porous PbCl2 layer that could resist rupture or breakdown. In addition, the electrode surface products were examined by scanning electron microscopy and X-ray diffractometry. The morphology of the as-formed PbCl2 layers showed a primitive dependence on the voltammetric conditions. X-ray diffraction analysis proved that only PbCl2 was formed on the electrode surface and no other products could be detected.