Efficient Electrochemical Oxidation of Methylene Blue in Wastewater Using Ti/SnO2-Sb/PbO2 Anodes: An Engineering Perspective

Abstract

In this research work, the Ti/SnO2-Sb interlayer was successfully prepared via the hydrothermal synthesis method. Subsequently, the outer PbO2 coating was fabricated through electrodeposition technology, resulting in the desired Ti/SnO2-Sb/PbO2 electrode. Characterization of the electrode's morphology revealed that it is entirely covered by beta-PbO2 particles, resulting in an increased surface area. Electrochemical tests demonstrated that the Ti/SnO2-Sb/PbO2 electrode exhibits superior performance compared to the Ti/SnO2-Sb electrode, with enhanced electron transfer efficiency and a greater capacity for generating active species. In degradation experiments using the Ti/SnO2-Sb/PbO2 electrode, the degradation rate of MB exceeded 90% within 40 min, underscoring the electrode's high efficiency. The optimal reaction conditions for the Ti/SnO2-Sb/PbO2 electrode were determined through an optimization model constructed via response surface methodology (RSM). A reaction time of 52 min was found necessary, along with an electrode plate spacing set at 2.2 cm and a current density maintained at 48 mA cm(-2). Under such parameters, the removal rate of MB achieved by the Ti/SnO2-Sb/PbO2 electrode reached as high as 92.73%. From the electron paramagnetic resonance spectra analysis, singlet oxygen (O-1(2)) and superoxide radicals (O-2(-)) were identified as the dominant active species produced by the Ti/SnO2-Sb/PbO2 anode.