Advanced experimental analysis on the synthesis and modification of zinc iron-based nanoparticles for separation and removal of pharmaceutical compounds

This study reports the visible-light-driven photocatalytic degradation of tetracycline (TC) in aqueous media using porous Co-doped ZnFe₂O₄ microspheres. ZnFe 2 O 4 (ZF) microspheres with a porous, spherical morphology were synthesized and subsequently doped with 5 wt% and 15 wt% cobalt (Co). The produced photocatalysts were subsequently assessed for their TC degradation performance under visible light irradiation from an LED lamp. The 15% Co-ZF catalyst showed the highest degradation efficiency among the three catalytic materials. A systematic study was conducted to assess the influence of TC concentration, catalyst concentration, pH, and lamp intensity on degradation efficiency. A degradation percentage of 92% was observed with a catalyst loading of 20 mg/L and the lowest TC concentration. Optimal degradation of 93% was achieved for 15%Co-ZF under 100 W LED lamp at pH = 5.52 after 240 min. Reusability studies revealed a slight decrease in degradation efficiency over three cycles, with a 9% reduction in the third cycle, indicating acceptable stability of the sample. Post-reaction XRD/FTIR analyses confirmed the structural stability of the photocatalyst, while scavenger experiments identified ·OH radicals as the dominant reactive species. These results highlight the potential of Co-doped ZF microspheres as efficient and reusable photocatalysts for the removal of TC from contaminated water sources.