Fluorine-Coordination Facilitated Interfacial Hydrolysis Builds Dual Sites for Efficient H2O2 Homolysis on FeOF.

Abstract

Fenton reaction has been widely applied in wastewater treatment, however, the homolytic cleavage of hydrogen peroxide (H2O2) toward selective formation of hydroxyl radical (•OH) remains a key challenge. In this study, the FeOF catalyst was synthesised by introducing highly electronegative fluorine atoms to modulate the coordination environment of iron sites. The resulting O-Fe-F configuration significantly enhances surface hydrolytic hydroxylation, increasing the density of dual sites by 158% and achieving a breakthrough with 4.6-fold enhancement in •OH production. The generation of dual sites shifts the Fe d-band center upward toward the Fermi level (FeOCl: -3.403 → -3.014 eV; FeOF: -3.350 → -3.126 eV), reduces the rate-limiting energy barrier (FeOCl: 0.13 → -0.56 eV; FeOF: 0.11 → -0.88 eV), and the sites act as a bridge between FeOF and H2O2 to facilitate electron transport. Moreover, the FeOF-loaded in hollow fiber membrane demonstrates efficient pollutant removal and robust long-term stability in continuous operation of real water matrices with a flux up to 398 L m-2 h-1. This work offers a new theoretical framework for the design of efficient Fenton-like catalysts.