Electrocatalytic Degradation of Cationic Red GTL on PbO₂ Electrode Modified with Graphene Oxide

Electrocatalytic oxidation using PbO 2 electrodes is a prospective strategy for treatment of bio-refractory dye wastewater. However, it is hindered by high energy consumption, poor degradation efficiency, and low anode stability. Here, PbO 2 electrodes were reconstructed by intercalating and surface-intervening with graphene oxide (GO) to enhance the stability of the composite electrodes and achieve high-efficiency oxidation of cationic red GTL. Compared with that on PbO 2 , reactive oxygen species (e.g., ·OH and ·O) on GO-PbO 2 were less consumed by the oxygen evolution reaction due to their larger spacing on GO-PbO 2 . In addition, GO-PbO 2 showed lower cell voltage than PbO 2 , indicating a higher electron transfer rate and lower energy consumption. The coupled free radical behavior and electron transfer enhanced the decolorization (1.7 times that of PbO 2 ) and mineralization (1.4 times that of PbO 2 ) rate of cationic red GTL on GO-PbO 2 . Furthermore, doping of GO with multilayer structure improved the stability of PbO 2 anode and its performance improvement mechanism was revealed. The prepared GO-PbO 2 electrode prolonged service-life (162 h) under accelerated electrolysis, about 2.7 times that of the PbO 2 electrode (60 h). This work provides a novel GO-PbO 2 electrode for efficient electrocatalytic degradation of GTL, and can be easily extended to electro-degradation of non-biodegradable wastewater.