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

Electrocatalytic oxidation using PbO2 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, PbO2 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 PbO2, reactive oxygen species (e.g., ·OH and ·O) on GO-PbO2 were less consumed by the oxygen evolution reaction due to their larger spacing on GO-PbO2. In addition, GO-PbO2 showed lower cell voltage than PbO2, 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 PbO2) and mineralization (1.4 times that of PbO2) rate of cationic red GTL on GO-PbO2. Furthermore, doping of GO with multilayer structure improved the stability of PbO2 anode and its performance improvement mechanism was revealed. The prepared GO-PbO2 electrode prolonged service-life (162 h) under accelerated electrolysis, about 2.7 times that of the PbO2 electrode (60 h). This work provides a novel GO-PbO2 electrode for efficient electrocatalytic degradation of GTL, and can be easily extended to electro-degradation of non-biodegradable wastewater.