<p>Emerging contaminants pose significant public health risks, highlighting the need for effective water decontamination technologies. Cerium dioxide (CeO₂) is a promising photoanode for degrading organic pollutants in photoelectrochemical systems due to its favorable physicochemical properties, environmental friendliness, and recyclability. Despite encouraging findings, further research is needed on CeO₂’s role in degrading pharmaceutical contaminants. In this study, CeO₂ photoanodes were obtained and evaluated in the photoelectrochemical degradation of ciprofloxacin (Cip) in aqueous media. The photoanode was synthesized by electrodeposition followed by annealing to obtain it as an immobilized layer on a glass substrate (FTO). CeO₂ was characterized for its optoelectronic, photoelectrochemical, structural, and morphological properties using RAMAN, XRD, XPS, UV–Vis, zeta potential, LSV, CA, EIS, and SEM, revealing a mixed valence composition (Ce⁴⁺/Ce³⁺), negative surface charge, and UV absorption. The effects of pH, ciprofloxacin concentration, and anodic polarization potential on degradation efficiency were assessed in a three-electrode photoelectrochemical cell. Radical scavengers (isopropyl alcohol, benzoquinone, and ammonium oxalate) revealed hydroxyl radicals (OH·) as the primary species responsible for degradation. The photoelectrochemical process showed a maximum efficiency of 65.8% at pH 9, [ciprofloxacin] = 5.0&#xa0;mg L⁻¹, and + 2.0&#xa0;V (vs. Ag/AgCl), while in synthetic wastewater, the efficiency increased to 89.7%. This study enhances understanding of CeO₂’s functionality and mechanism as a photoanode for ciprofloxacin degradation.</p> Graphical abstract <p></p>