Kinetic Study and Optimization of Tetramethylthionine Chloride Photodegradation by Iron-Perylene MOF with Hydrogen Peroxide Using Response Surface Methodology

This study aimed to synthesize and characterize an iron-perylene metal-organic framework (MOF) as a photocatalyst for the degradation of tetramethylthionine chloride in the presence of hydrogen peroxide. Iron-based MOF with perylene-3,4,9,10-tetra carboxylate (PTC) ligands was produced through a solvothermal technique and was characterized for its morphology, optical properties, surface area, thermal stability, and electrochemical behavior. The results showed that Fe-PTC MOF had a tubular crystalline structure with an average crystal size of 51 nm, a bandgap energy of 1.94 eV, and was responsive to visible light. Thermal analysis revealed a significant weight loss of 63.53% between 390 °C and 490 °C due to the decomposition of the organic linker, with an exothermic heat release of 5.97 J/mg. Electrochemical characterization showed an onset oxidation potential of 0.641 V (vs. Standard Hydrogen Electrode (NHE)) and a calculated Lowest Unoccupied Molecular Orbital (LUMO) energy level of –1.299 V, indicating potential applications in photocatalytic and photovoltaic technologies. Photocatalytic activity tests demonstrated that the degradation of tetramethylthionine chloride followed pseudo-first-order kinetics, and optimization using Response Surface Methodology (RSM) identified the optimal conditions for degradation: 1.5 mg of photocatalyst, 0.2 M H2O2 concentration, and 133 min of contact time. These results underscore the effectiveness of Fe-PTC MOF in treating dye-contaminated textile wastewater under illumination with visible light.