CuS-MIL-53(Fe) Framework as a Heterogeneous Fenton Catalyst for the Removal of Organic Contaminants.

Developing a suitable Fenton catalyst capable of efficient redox cycling between Fe and Fe for dye degradation is a promising approach for enhancing catalytic activity. In this work, we synthesized a rod-like CuS-MIL-53(Fe) framework via a solvothermal process. The incorporation of CuS into pristine MIL-53(Fe) induced a significant structural transformation from an octahedral to a rod-like morphology, resulting in an enhanced surface area from 130.50 m/g (MIL-53(Fe)) to 182.96 m/g (CuS-MIL-53(Fe)), as confirmed by BET analysis. The composite demonstrated excellent performance in the Fenton reaction, achieving 94.4% removal of methylene blue (MB) within 50 min with a rate constant of 0.052 min. In contrast, MIL-53(Fe) achieved only 64.4% degradation in the same time frame, with a lower rate constant of 0.020 min under identical reaction conditions. Both X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) analyses indicated interfacial electron movement from CuS into MIL-53(Fe), which resulted in a 30% increase in catalytic performance for methylene blue decomposition using the CuS-MIL-53(Fe) catalyst, as compared to that of pristine. The primary reactive species driving the degradation process were identified as hydroxyl radicals (OH). The composite maintained its catalytic efficiency even after five cycles, reflecting its superior stability. This investigation centers on the fabrication of new Fenton catalysts aimed at improving environmental decontamination methods.