Needle ZrOx loaded NiFe2O4 catalysts for Photo-Fenton degradation of bisphenol A and 4 nitrophenol

This study investigates the synthesis of ZrO_x-loaded NiFe₂O₄ photocatalysts (1, 2, and 3 wt%) through co-precipitation and wet impregnation methods for environmental and health applications. The structural analysis revealed a cubic crystal structure, with ZrO_x doping enhancing charge separation and mobility by converting the morphology from fibrous to needle-like. Under visible light (VL) and H₂O₂ activation, the ZrO_x(3 wt%)/NiFe₂O₄ composite achieved high degradation efficiencies (98.5% for Bisphenol A and 98.2% for 4-Nitrophenol) in 120 min via the Photo-Fenton mechanism. Kinetic analysis showed pseudo-first-order behavior with rate constants of 0.945 min⁻¹ for BPA and 0.904 min⁻¹ for 4-NP. The catalyst demonstrated stability with 91.5% efficiency retention after multiple cycles. DFT calculations indicated favorable HOMO-LUMO alignments and electrostatic potentials. Additionally, ZrO_x(3 wt%)/NiFe₂O₄ exhibited selective cytotoxicity against breast cancer cell lines, while maintaining high viability in HEK-293 cells. The results suggest that ZrO_x(3 wt%)/NiFe₂O₄ composites are promising for environmental and biomedical applications.