Design of ternary TiO2 -based nanocomposite for enhanced photocatalysis of MNZ: application to pharmaceutical wastewater treatment

This study reports the successful synthesis of ternary TiO ₂ /ZnO/SnO ₂ nanostructures for the photodegradation of metronidazole, which was selected for its widespread use, high water stability, and contamination of aquatic matrices in levels that led to the induction of antibiotic resistance. Ternary TiO ₂ /ZnO/SnO ₂ nanostructures were synthesized by a facile two-step co-precipitation method using metal oxides and commercially available TiO ₂ nanoparticles. The structural and morphological analysis of the material has been performed by both SEM and TEM, showing the superficial surface area, and the crystal structure was studied using XRD and XPS, confirming the formation of nanostructures composed of TiO ₂ /ZnO/SnO ₂ and their oxidation states. A validated HPLC method has been developed to monitor metronidazole concentrations during treatment. The photocatalytic activity of the ternary nanostructures was studied using different variables such as initial drug concentration, catalyst dosage, and pH. The demonstrated high catalytic performance in samples and incurred wastewater of 90% and 76%, respectively was achieved at neutral pH with a photocatalyst concentration of 0.5 mg/mL in 120 minutes, providing novel and rapid nanocomposites for the efficient removal of imidazoles from wastewater.