Fabrication of Ga₂O₃–PbO₂ electrode and its performance in electrochemical advanced oxidation processes

Owing to its high oxygen evolution potential, PbO₂ electrode is one of the candidates for electrochemical advanced oxidation processes (EAOPs). To further improve its performance as EAOP electrode, a Ga₂O₃-doped PbO₂ electrode (Ga₂O₃–PbO₂ electrode) was fabricated by the composite plating method. SEM and XRD results showed that the crystalline in the coating of Ga₂O₃–PbO₂ electrode is more uniform and in smaller size than that in the undoped PbO₂ electrode, which provided a higher specific surface area. The electrochemical studies showed that the Ga₂O₃–PbO₂ electrode had higher oxygen evolution potential (OEP) and smaller electrode surface impedance, which is a benefit for the formation of hydroxyl radicals (·OH). The electrochemically degradation test using bromocresol green sodium (BG) solution and glucose solution as the simulated wastewater showed that the kinetics of electrochemical catalytic degradation is a pseudo-first-order reaction, and the reaction rate constant on Ga₂O₃–PbO₂ electrode was 2 times accelerated.