Enhancement of the Activity of Electrochemical Oxidation of BPS by Nd-Doped PbO2 Electrodes: Performance and Mechanism

The electrochemical oxidation processes have attracted tremendous attention on the destruction of toxic and non-biodegradable organics. A series of neodymium (Nd)-doped PbO2 electrodes (Ti/PbO2-Nd) were synthesized through a pulse electrodeposition method, and its activity of bisphenol S (BPS) removal was further examined. The morphologies and structures were characterized by the X-ray diffraction (XRD), scanning electron microscopy (SEM) and an energy dispersive spectrometer (EDS). The performance, energy consumption and mechanism of electrochemical oxidation of BPS by Ti/PbO2-Nd electrode were also discussed. Compared to the traditional Ti/PbO2 electrode, the Ti/PbO2-Nd enables finer crystal particles, facilitating the oxygen evolution overpotential (OEP) from 1.41V to 1.55V and the generation of hydroxyl radicals (•OH). Moreover, lower duty cycles during the preparation of the electrode also contribute to the tapering size of crystals. The results show that the Ti/PbO2-Nd electrode exhibits relatively high activity in the anodic oxidation of BPS. Over 95% of BPS could be removed with the current density of 15 mA cm−2. Moreover, the energy consumption of BPS degradation on Ti/PbO2-Nd electrode is 60.26 kWh m−3, much lower than that on Ti/PbO2 electrode (95.45 kWh m−3). To conclude, the Ti/PbO2-Nd electrode has been proven to be a promising material for BPS removal.