LEAD DIOXIDE ELECTRODEPOSITION AND ITS APPLICATION - INFLUENCE OF FLUORIDE AND IRON IONS

The electrodeposition of PbO2 on Pt in the presence of F- and Fe(III), separately or together in the growth solution, is examined. The elect rodeposition follows the same reaction scheme previously reported in t he literature for PbO2. The electrocatalytic activity of the resulting oxides is assessed for the reactions of O-2 and O-3 evolution. Fluori de and iron into PbO2 have different effects on the electrocatalytic a ctivity of PbO2 for O-2 evolution and O-3 formation. With F-PbO2 the f irst process is favoured and the second one inhibited, whereas with Fe -PbO2 electrodes we observed the opposite trend. Lead dioxide grown fr om F- and Fe(III) containing solutions showed the highest activity for O-3 formation. The larger amount of iron incorporated into PbO2 in th e presence of F- is proposed as a possible cause of the enhanced activ ity for ozone formation of (F-Fe)-PbO2 electrodes. (C) 1997 Elsevier S cience S.A. All rights reserved.