• • Under optimized conditions (50 mmol·L−1 Na2SO4, 1.67 mA·cm−2, pH 2), sulfathiazole removal reached 95.7% with 76.7% TOC removal, demonstrating near-complete degradation and significant mineralization, critical for reducing antibiotic resistance in wastewater effluents.
• • The BiVO4/TiO2 heterostructure exhibited a bandgap of 2.12 eV and a valence band edge at 2.775 V vs. RHE, enabling efficient generation of ·OH, 1O2, and SO4−· radicals under visible light, which is essential for oxidizing recalcitrant sulfonamide structures.
• • Removal efficiencies varied from 52.0% (sulfaguanidine) to 95.7% (sulfathiazole), indicating that molecular structure—particularly electron-donating groups like guanidine—affects degradation kinetics, guiding targeted design of treatment processes.
• • The system maintained high stability and catalytic efficiency across acidic and alkaline conditions, suggesting operational robustness for real-world wastewater treatment, where pH fluctuations are common.