Preparation and characterization of hydrophobic stearic acid-Yb-PbO2 anode and its application on the electrochemical degradation of naproxen sodium

Abstract

A novel hydrophobic stearic acid-Yb-PbO2 (SA-Yb-PbO2) electrode with high oxygen evolution overpotential and long service lifetime was successfully fabricated through electrodeposition approach. The characterization of SA-Yb-PbO2 electrode, including surface morphology, elemental components, hydrophobicity, and crystal lattice structure, were performed. The results indicated that stearic acid's adulteration could enhance oxygen evolution overpotential and increase active specific surface area and the amounts of active sites. Then, the hydrophobic electrodes were used as anodes for electrolysis of naproxen sodium. The SA-Yb-PbO2 electrode showed better performance on naproxen sodium degradation than Yb-PbO2 electrode, exhibiting higher removal efficiency, lower energy consumption and higher mineralization current efficiency. Furthermore, the adulteration of stearic acid could greatly promote the stability and reusability of the electrodes for naproxen sodium degradation. The enhancement of electrode performance and oxidation power was related to high oxygen evolution overpotential and strong generation capability of OH caused by electrode's hydrophobic surface. Moreover, the degradation pathway and corresponding byproducts of naproxen sodium were obtained by HPLC and HPLC/MS assay, which revealed that naproxen sodium could be effectively mineralized by hydrophobic SA-Yb-PbO2 anode. These results presented that the organic pollutant wastewater containing naproxen sodium could be effectively decontaminated by electrochemical approach using hydrophobic SA-Yb-PbO2 electrode as anode.