Pharmaceuticals are widely distributed in the environment and directly discharged into natural waters such as rivers, lakes, and oceans through sewage. Although pharmaceutical residues in the aquatic environment are present at low levels, typically nanograms or micrograms per liter, their potential ecological hazards are attracting increasing attention [1]. Electrochemical oxidation as a particular technology in advanced oxidation processes (AOPs) can oxidize a diverse range of water-soluble organic pollutants through the production of hydroxyl radicals (OH•) and treat bio-refractory organic wastewater [2]. The PbO2 electrode is a desirable anode material due to its oxygen evolution potential, high resistance to corrosion, favorable conductivity, cost, efficiency, high catalytic activity, and sustained durability, particularly in acidic environments [3]. Sodium dodecyl sulfate (SDS) is a good choice to modify the active surface of the electrode [4]. In this research, the Ti/TiO2-PbO2 electrode was fabricated through the process of electrodeposition of βPbO2 onto the intermediate layer of TiO2 that had been previously electrodeposited onto the titanium substrate. To enhance the efficiency and stability of the electrode used for the electrochemical degradation of cephalexin (CEX) as a form of organic pollution in wastewater, the βPbO2 electrode underwent modification through the addition of SDS. Crystal structure, surface morphology, and electrocatalytic activity of electrode were characterized by scanning electron microscopy (SEM), Energy-Dispersive X-ray (EDS) spectroscopy, X-ray Diffraction (XRD), Linear sweep voltammetry (LSV), cyclic Voltammetry (CV), Differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). The function of the electrode in CEX degradation was assessed using liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS) and chemical oxygen demand (COD) analyses]. The effects of initial CEX current density, concentration, and pH on the CEX degradation efficiency were investigated. The maximum degradation efficiency of 97.6% was achieved at pH 7, and the maximum COD removal of 70.26% was observed at pH 3 when utilizing a 50 cc CEX solution under a current density of 20 mA cm-2. Then, the degradation mechanism was proposed.
