Optimized Fabrication of TiO2 Nanotubes Array/SnO2-Sb/Fe-Doped PbO2 Electrode and Application in Electrochemical Treatment of Dye Wastewater

Abstract

A TiO2 nanotubes array/SnO2-Sb/Fe-doped PbO2 electrode with high oxygen evolution potential and enhanced electrochemical oxidation performance was successfully manufactured. The surface morphology and electrochemical performance of the electrode were characterized by a field emission scanning electron microscope, linear sweep voltammetry, and electrochemical impedance spectroscopy experiments. The effect of Fe doping concentration on the electrode performance was also investigated. This study shows the doping of Fe on a PbO2 electrode improved the micro-morphology and the conductivity of the electrode. The oxygen evolution potential was also increased to 1.95 V [versus a saturated calomel electrode (SCE)] via Fe doping. The optimal condition of Fe doping concentration was 0.02 M. The optimized electrode showed that the decoloration rate and total organic carbon removal ratio of methylene blue approached 98% and 96% after 30 min of electrochemical treatment, respectively. The accelerated lifetime of the optimized Fe-doped electrode was approximately 4.3 times larger than that of the undoped PbO2 electrode. A Ti/TiO2 nanotubes array/SnO2-Sb/Fe-doped PbO2 anode shows potential application in the electrochemical treatment of organic dye wastewater.