Construction of a Pr/CDs/SSS/PbO composite electrode for highly efficient degradation of organic pollutants

In this study, a Pr/CDs/SSS/PbO 2 electrode with good electrocatalytic activity and superior stability was successfully prepared by an electrodeposition process. XRD results showed that the doping of the Pr element inhibited the PbO 2 crystal growth, resulting in the complete disappearance of the α-PbO 2 diffraction peaks. Compared with the pure PbO 2 electrode, the Pr/CDs/SSS/PbO 2 electrode possesses a smaller grain size and a more compact electrode surface structure. In addition, the results of XRD and XPS confirmed that Pr 3+ and Pr 4+ existed simultaneously in the electrode, which increased the oxygen precipitation over potential (1.96 V) and reduced the interfacial resistance (5.01 Ω) of the Pr/CDs/SSS/PbO 2 electrode. Significantly, the prepared Pr/CDs/SSS/PbO 2 electrode showed the highest catalytic activity when the electrode was prepared in 5 mmol L −1 of Pr-containing solution, and the degradation of MB by the Pr/CDs/SSS/PbO 2 electrode was 98.2% after 180 min of degradation under the conditions: 50 mg L −1 of MB, pH = 5, and 30 mA cm −2 of current density. The removal rate of TOC was 58%, which was much higher than that of the pure PbO 2 electrode (3.44%). In general, the Pr/CDs/SSS/PbO 2 electrode can be considered an efficient and low-cost anode material for the electrochemical treatment of organic wastewater. In this study, a Pr/CDs/SSS/PbO 2 electrode with good electrocatalytic activity and superior stability was successfully prepared by an electrodeposition process.