Engineering Dinuclear Iron Sites in Fluorinated Mesoporous Zirconium Metal-Organic Frameworks for Enhanced Photo-Fenton Catalysis

Mesoporous zirconium MOFs provide an attractive platform for combining accessible active sites with tunable electronic properties. In this work, we present a fluorinated mesoporous Zr-MOF incorporating dinuclear iron sites (MIP-206-F-Fe) as an advanced photo-Fenton catalyst for antibiotic degradation in water. Pair distribution function (PDF) analysis and Fe K-edge X-ray absorption spectroscopy (XAS) confirm that iron is incorporated as framework-bound Fe(III) species, consistent with binuclear motifs associated with the Zr6 clusters in MIP-206. Linker fluorination significantly enhances photocatalytic activity toward chloramphenicol degradation under simulated sunlight. Transient absorption spectroscopy (TAS) reveals prolonged charge-carrier lifetimes in MIP-206-F-Fe, indicating suppressed recombination and more efficient interaction with H2O2. The combined structural and photophysical analyses establish a direct correlation between local Fe structure, excited-state dynamics, and photo-Fenton performance. These findings provide mechanistic insight into the design of chemically engineered MOFs for solar-driven degradation of organic pollutants in water.