ELECTROCHEMICAL PROPERTIES OF TI SNO2-SB2O5 ELECTRODES PREPARED BY THE SPRAY-PYROLYSIS TECHNIQUE/

Cyclic voltammetry for the ferri-ferrocyanide redox couple has been us ed to study the Ti/SnO2-Sb2O5 electrode prepared by spray-pyrolysis un der different conditions. The obtained results shows that increasing t he preparation temperature and the duration of coating deposition resu lts in a decrease of i(p) and an increase of Delta E(p) for the ferri- ferrocyanide couple. This deviation from reversibility has been attrib uted to the formation of a titanium oxide layer at the Ti/coating inte rface. Concerning oxygen evolution at the Ti/SnO2-Sb2O5 anodes, a mech anism is proposed in which water is discharged at the anode forming hy droxyl radicals which are further oxidized to form dioxygen. Finally, a generalized mechanism for oxygen evolution at oxide electrodes has b een proposed.