Fabrication of sulfide nanoscale zero-valent iron and heterogeneous Fenton-like degradation of 2,4-Dichlorophenol

Surface sulfidation has become a desirable technique to enhance the physicochemical properties of nanoscale zero-valent iron (NZVI) and improve the decontamination efficiency for organic pollutants. However, the macroscopic elimination performance and microscopic reaction mechanism of sulfide NZVI (SNZVI) towards organic matters remains uncovered. Herein, we fabricated SNZVI via one-step dithionite-method and applied it for heterogeneous Fenton-like elimination of 2,4-Dichlorophenol (DCP). The sulfidation technique greatly improved the stability, specific area, oxidized resistance, hydrophobicity, and functionality. The efficiency of degradation (86.3%) was approximately 7 times higher than adsorption (12.6%) under N2 condition, indicating the promising potential of SNZVI in environmental governance. Moreover, Fenton-like reaction and reactive oxygen species (ROS) were confirmed to dominate the degradation process, and the generated radicals had priority to degrade DCP rather than corroded SNZVI. Furthermore, the result of gas chromatography-mass spectrometry (GC–MS) confirmed that DCP was mainly decomposed into harmless alkanes and inorganic matters, which significantly reduced the perniciousness of DCP. Overall, this research bridged the knowledge gap between organic pollutant removal and the advanced oxidation reaction of NZVI-based materials after surface sulfidation.