Synthesis and photocatalytic performance of ZnFe2O4 on the degradation of tetracycline in water

Abstract Tetracycline (TC) contamination in water systems poses significant environmental and public health risks, including antibiotic resistance and ecosystem disruption. This study investigates the enhanced photocatalytic degradation of TC using zinc ferrite (ZnFe₂O₄) nanoparticles coupled with persulfate (PS) activation under visible light. The ZnFe₂O₄ catalyst was synthesised using a co-precipitation technique and characterised using XRD, SEM, TEM, and UV-vis spectroscopy, which verified its spinel structure, polycrystalline morphology, and narrow bandgap of 1.82 eV. The hybrid ZnFe₂O₄/PS system demonstrated remarkable synergy, achieving 97.3% TC degradation within 120 min, significantly outperforming ZnFe₂O₄ alone (66.9%) or PS alone (negligible degradation). Kinetics analysis revealed a pseudo-first-order rate constant of 3.25 × 10⁻² min⁻¹, attributed to the efficient generation of superoxide radicals (•O₂⁻) as the principal active species, validated by scavenging experiments. The system also demonstrated versatility, degrading diclofenac (64%) and methylene blue (71%), thereby highlighting its potential for remediation of diverse pollutants. This work presents a sustainable and efficient strategy for treating antibiotic wastewater, leveraging the synergistic interplay between photocatalysis and persulfate activation to advance Sustainable Development Goals (SDG) 6 (clean water) and SDG 14 (aquatic ecosystem protection).