Cyclic voltammetry for the ferri-ferrocyanide redox couple was used to study the Ti/SnO2-Sb2O5 electrode prepd. by spray-pyrolysis under different conditions. Increasing the prepn. temp. and the duration of coating deposition results in a decrease of ip and an increase of DEp for the ferri-ferrocyanide couple. This deviation from reversibility is attributed to the formation of a titanium oxide layer at the Ti/coating interface. Concerning oxygen evolution at the Ti/SnO2-Sb2O5 anodes, a mechanism is proposed in which water is discharged at the anode forming hydroxyl radicals which are further oxidized to form dioxygen. Finally, a generalized mechanism for oxygen evolution at oxide electrodes is proposed. [on SciFinder (R)]