Preparation and characterization of Ti/SnO2-Sb2O3/α-PbO2/Ce-Nd-β-PbO2 composite electrode for methyl orange degradation

The present study focused on the preparation, characterization, and application of cerium (Ce) and neodymium (Nd) co-doped lead (PbO2) electrode, i.e., Ti/SnO2-Sb2O3/α-PbO2/Ce-Nd-β-PbO2. The electrochemical activities of the modified electrode were investigated and compared with those of Ce-PbO2, Nd-PbO2, and pure PbO2 electrodes. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were used to characterize the surface morphology, crystal structure, and elemental states of the modified electrode. The Ce and Nd co-doped PbO2 electrode had smaller crystal particles, more compact structure, and higher activity of electrocatalysis compared with the single-doped and undoped PbO2 electrodes. Linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) were also utilized to study the electrochemical response of the modified electrodes. The results show that the prepared Ce-Nd-PbO2 electrode has the highest O2 evolution potential (OEP) and lowest charge transfer resistance, suggesting that it has the lower energy consumption than the other three kinds of electrodes. Electrochemical oxidation methyl orange (MO) as a model dye wastewater was studied to evaluate the potential applications of this modified electrode in environmental science. It was found that the Ce-Nd-PbO2 electrode exhibited higher MO and chemical oxygen demand (COD) removal efficiency than single-doped and pure PbO2 electrodes.