Sustainable Photocatalytic Degradation of Ibuprofen Using Se-Doped SnO2 Nanoparticles Under UV–Visible Irradiation

The increasing presence of pharmaceutical residues such as ibuprofen in aquatic environments represents a growing concern due to their persistence and limited biodegradability. In this study, selenium-doped tin oxide (SnO2:Se) nanoparticles covered with glycerol were synthesized via a microwave-assisted method to evaluate their photocatalytic performance in the degradation of ibuprofen under ultraviolet (UV) and visible light. Optimal synthesis parameters were determined at pH 7.5–8.0 and 130 °C, yielding stable, dark-brown colloidal suspensions. HRTEM analysis revealed a coexistence of one-dimensional (1D) nanowires and zero-dimensional (0D) quantum dots, confirming nanoscale morphology with crystallite sizes between 8 and 100 nm. EDS analysis confirmed the presence of Sn, O, and trace Se (0.1 wt%), indicating Se incorporation as a dopant. UV–Vis spectroscopy showed strong absorption near 324 nm and slight band-gap narrowing in the Se-doped samples, suggesting enhanced visible-light responsiveness. Photocatalytic experiments demonstrated an ibuprofen degradation efficiency of ~60% under visible light and 80% under UV irradiation with aeration, compared to only 5% removal using commercial SnO2. The enhanced performance was attributed to Se-induced band-gap modulation, effective charge-carrier separation, and singlet oxygen generation.