Electrochemical degradation of phenol in aqueous solution using PbO₂ anode

The PbO₂ electrode was prepared by electrodeposition method in this paper. The electrode was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and cyclic voltammetry (CV). The electrochemical oxidation of phenol in aqueous solution was studied by galvanostatic electrolysis using PbO₂ electrode as anode. UV spectroscopy, total organic carbon (TOC) and chemical oxygen demand (COD) measurements were conducted to study the kinetics of phenol electrochemical degradation and the mineralization efficiency under different current densities. The experimental results showed that the applied current density had a positive influence on the degradation of phenol and removal of TOC, but a higher current density led to lower current efficiency and higher energy consumption. The phenol degradation always followed a pseudo-first-order kinetics. In addition, aromatic intermediates and general carboxylic acids generated in the degradation of phenol have been indentified using high-performance liquid chromatography (HPLC) and a general pathway for the electrochemical degradation of phenol on PbO₂ anode was proposed.