Electrochemical removal of a pharmaceutical pollutant from aqueous solution using Ti/nano ZnO-Bi₂O₃ modified electrode

This research investigates the utilization of a modified Ti/nano ZnO-Bi₂O₃ electrode for the electrochemical advanced oxidation-based removal of a pharmaceutical pollutant from an aqueous solution. To analyze the surface properties of Ti/nano ZnO, Ti/nano Bi₂O₃, and Ti/nano ZnO-Bi₂O₃ electrodes made using electrophoretic deposition, various analytical methods were used. These methods included X-ray diffraction analysis, energy-dispersive spectroscopy, and field emission scanning electron microscopy confirmed the presence of ZnO nanoparticles and Bi₂O₃ nanoparticles in a layer that is uniformly coated on the Ti/nano ZnO-Bi₂O₃ electrode. Beside linear sweep voltammetry and Tafel plots confirmed the increased stability and electrocatalytic activity of the modified electrode compared to the initial electrode. Chronopotentiometry and chronoamperometry verified the stability and better conductivity of the nanocomposite electrode, and according to electrochemical impedance spectroscopy, charge transfer in the modified electrode has improved by 87%. We evaluated the effectiveness of the Ciprofloxacin removal process by considering factors, such as pH in the range of 3–11, electrolyte concentration in the range of 1–7 g L⁻¹, and current density in the range of 1.2–5.75 mA cm⁻². We selected Ciprofloxacin as the specific pollutant for evaluating pollutant removal from aqueous solutions due to its widespread use and presence in the environment. We determined the optimal parameter values to be 6.25 mA cm⁻², 5, and 3 g L⁻¹. Under these optimal conditions, the efficiency of ciprofloxacin removal reached 96.33% within 300 min.