Fabrication of Mn²⁺–Zr⁴⁺@MgFe₁₂O₁₉ for photocatalytic degradation of enrofloxacin antibiotic

Antibiotic contamination in water bodies has become a critical environmental issue due to its persistence, bioaccumulation, and resistance to conventional wastewater treatment methods. This study reports the synthesis, characterization, and photocatalytic application of Mn²⁺–Zr⁴⁺-doped magnesium (Mg) M-type hexaferrites for degrading enrofloxacin (ENF) antibiotic in veterinary wastewater. Six samples with varying doping concentrations (x = 0.00–0.1, y = 0.00–1.00) were synthesized using the sol–gel auto-combustion method. Comprehensive structural, morphological, and optical analyses confirmed successful incorporation of manganese and zirconium ions into the M-type magnesium hexaferrite matrix. The crystal sizes of the synthesized samples decreased from 84.2 to 75.9 nm, while the unit cell volume increased from 685.45 to 701.85 ų with increasing doping concentrations. The bandgap energy was reduced from 2.02 to 1.79 eV. The optimized composition (Mg_0.92Zr_0.08Fe_11.2Mn_0.8O₁₉) demonstrated the highest degradation efficiency by way of achieving 95.5% ENF removal with a rate constant of 0.036 min⁻¹ in only 80 min. These results highlight the remarkable potential of Mn²⁺–Zr⁴⁺-doped magnesium M-type hexaferrites as efficient and sustainable photocatalysts for environmental remediation applications.