Preparation of a Praseodymium Modified Ti/SnO2-Sb/PbO2 Electrode and its Application in the Anodic Degradation of the Azo Dye Acid Black 194

A series of praseodymium modified Ti/SnO2-Sb/PbO2 (Ti/SnO2-Sb/PbO2-Pr) electrodes were synthesized by doping PbO2 with praseodymium and the effect of Pr doping on the electrode catalytic activity toward the anodic oxidation of the model dye C.I. Acid Black 194 (AB-194) was examined in aqueous solution. The electrocatalytic activity of a Ti/SnO2-Sb/PbO2 electrode can be greatly improved by adding an appropriate amount of Pr into the PbO2 layer. Accelerated life tests indicate that Pr doping also dramatically improves the stability of the Ti/SnO2-Sb/PbO2 anode. The introduction of Pr enhanced the formation of oxygen vacancies and surface hydroxyl groups, resulting in better activity and stability of the Ti/SnO2-Sb/PbO2-Pr electrode. A possible degradation pathway of AB-194 during the anodic oxidation process is proposed based on hydroxyl radical attack of the organic reactant.