Next-generation photo-Fenton treatment using MIL-100(Fe) synthesized through a green route for sustainable remediation of pharmaceutical wastewater

Abstract

The photocatalytic Fenton oxidation reaction of paracetamol (PCT), as a widely used pharmaceutical and persistent water contaminant, was investigated using RTG-MIL-100(Fe) framework, prepared via a KI-assisted, solvent free, room temperature synthesis, in the presence of H₂O₂ under UV irradiation. The mild conditions synthesis of RTG-MIL-100(Fe) is investigated, and the material is comprehensively assessed through characterized using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Brunauer–Emmett–Teller (BET), and X-ray Photoelectron Spectroscopy (XPS). The catalytic system is introduced as a source of photo-Fenton-like reaction and demonstrated a dual mechanistic pathway involving both semiconductor-like photoexcitation and open metal site (OMS) activation. The operating Fenton parameters are optimized and the experimental research revealed that the reaction is working at the room temperature using 400 ppm H₂O₂, 20 mg/L of RTG-MIL-100(Fe)at natural pH of wastewater (5.5) and the PCT reached almost complete removal 99.6%. The synergistic interaction of photogenerated charge carriers and OMS-driven Fenton-like processes resulted in efficient oxidative mineralization of PCT to CO₂ and H₂O. Furthermore, the reaction is endothermic in nature and following the first order reaction kinetics. These findings highlight the potential of KI-modified MOF-based photo-Fenton catalysts as sustainable and robust materials for the treatment of pharmaceutical wastewater.