Non-traditional power supply mode: Investigation of electrodeposition towards a better understanding of PbO2 electrode for electrochemical wastewater treatment

Abstract

The power supply mode is a non-negligible character in electrochemical process. Constant current mode is used in the traditional electrodeposition preparation process of PbO2 electrode, and there are very few studies on its electrodeposition power supply mode. In this paper, two non-traditional power supply modes (linear increase power supply mode and linear decrease power supply mode) were used to fabricate PbO2 electrodes, and the properties of prepared electrodes were compared with those of the traditional constant current power supply mode. On the premise of improving the electrode properties, the non-traditional power supply mode also significantly reduced the energy consumption of the electrodeposition process of PbO2. After material characterization (Scanning electron microscope, X-ray diffraction), electrochemical characterization (Electrochemical impedance spectroscopy, linear sweep voltammetry etc.) and stability test, it can be seen that the electrode surface prepared by the non-traditional power supply mode was spherical particles and its average grain size was smaller than that of the traditional one. The PbO2 electrode prepared by linear increase power supply mode had higher oxygen evolution overpotential (1.962 V), more active sites, smaller membrane impedance (33.15 Ω) and better stability (accelerated life up to 125.1 h). In the electrocatalytic oxidation tests of the three electrodes, the PbO2 electrode prepared by linear increase mode had the best performance in decolorization rate, Chemical oxygen demand removal rate, average current efficiency and energy consumption. Owing to favorable effects obtained, non-traditional power supply mode could be considered a promising alternative for PbO2 electrode preparation and applied electrochemical process for wastewater treatment.