PHOTOCATALYTIC DEGRADATION OF SULFAMONOMETHOXINE (SMM) BY H₃PW₁₂O₄₀/TiO₂: PREPARATIVE OPTIMIZATION, KINETIC CHARACTERIZATION AND GENERALIZATION STUDY

The pervasive occurrence of antibiotic residues in aquatic systems has emerged as a critical environmental concern worldwide, posing substantial risks to ecological integrity and public health.This investigation presents a strategic approach to combat this issue through the rational design and fabrication of a novel H₃PW₁₂O₄₀/TiO₂ composite photocatalyst synthesized via an optimized sol-gel protocol.The systematic optimization of critical preparation parameters, including the PW₁₂/TiO₂ mass ratio (0.25-0.55), calcination temperature (400-600°C), and calcination duration (1-4 hours), were meticulously conducted to maximize photocatalytic efficiency.The optimally engineered catalyst, obtained through calcination at 500°C for 2 hours with a precise PW₁₂/TiO₂ mass ratio of 0.35, demonstrated exceptional performance in degrading sulfamonomethoxine achieving a remarkable degradation rate constant of 0.2121 min⁻¹ under UV irradiation.The degradation kinetics adhered rigorously to a pseudo-first-order model, confirming the efficiency of the photocatalytic process.Comprehensive characterization via X-ray diffraction and scanning electron microscopy elucidated the underlying enhancement mechanisms, revealing that PW₁₂ doping effectively stabilized the anatase phase, suppressed crystal growth, increased specific surface area, and generated irregular microporous architectures.Furthermore, the composite catalyst exhibited outstanding reusability over multiple cycles and demonstrated broad-spectrum applicability, successfully degrading over 90% of sulfamethazine and ofloxacin within 30 minutes.This study establishes a viable pathway for developing advanced TiO₂-based photocatalytic systems with promising potential for sustainable remediation of antibiotic-contaminated water environments.