Glutathione-coated Fe3O4 nanoparticles with enhanced Fenton-like activity at neutral pH for degrading 2,4-dichlorophenol

Abstract

Magnetic glutathione (GSH)-functionalized nanocomposites (Fe₃O₄@GSH) were synthesized via an oxidative polymerization method and characterized as a heterogeneous Fenton-like catalyst for 2,4-dichlorophenol (2,4-DCP) degradation at neutral pH (pH = 6.5). The performance of the composite was extensively investigated in terms of catalytic activity and factors (H₂O₂ dosage, catalyst loading, initial solution pH, and 2,4-DCP concentration) influencing 2,4-DCP degradation. Iron leaching, primary reactive oxidizing species, and catalyst reusability were also investigated. The results showed that the removal efficiency can reach up to 99% within 240 min in the presence of Fe₃O₄@GSH, whereas pure Fe₃O₄ cannot operate under the same circumstances. Hydroxyl radicals (˙OH) were found as the main reactive oxidizing species responsible for pollutant degradation, and the final removal efficiency still reached 94% after recycling three times. The role of GSH can be ascribed to the acceleration of iron leaching from the surface of Fe₃O₄ and collective action for H₂O₂. The Fe₃O₄@GSH catalyst may provide new insights into the Fenton-like process for enhancing contaminant degradation.