A new catalyst derived from the sulfur-doped metal-organic framework for Fenton-like reaction

Fenton-like reaction exhibits considerable advantages in the remediation of pollutants. To fabricate an efficient catalyst becomes an issue concerning the performance enhancement in Fenton-like reaction. Herein, S-Fe-MOF-400 which was derived from a sulfur-doped metal-organic framework (Fe-MOF), was newly prepared and exhibited high ability for H₂O₂ activation during Fenton-like reaction. The results showed that the sulfurization effectively reduced the charge transfer resistance (R_ct) of S-Fe-MOF-400, and facilitated the charge transfer, consequently enhancing the catalytic performance of S-Fe-MOF-400 in the Fenton-like reaction. XRD analysis revealed that FeS₂ was the predominant reactive component in S-Fe-MOF-400 with a regular cubic structure and pronounced crystallinity. Additionally, the presence of low-valent sulfur ensured the availability of Fe (II), thereby facilitating the occurrence of the Fenton reaction. Under optimal conditions, the removal efficiency of pollutants reached 86.7 % within 60 min, resulting in total organic carbon (TOC) removal efficiency at 40.6 %. Quenching experiments and electron paramagnetic resonance (EPR) detections revealed that ^•OH, ¹O₂, and ${\text{O}}_2^{\text{•}-}$ synergistically participated in the Fenton-like reaction^, with ^•OH being the primary active species. The activation process of H₂O₂ induced by S-Fe-MOF-400 mainly yielded hydroxyl radicals and superoxide radicals. The ¹O₂ was generated through two following pathways: (i) the transformation of superoxide and hydroxyl radicals, and (ii) the conversion of natural oxygen molecules (O₂). This current study illustrated the significant potential for the application of sulfur-modified Fe-MOF in the Fenton-like reaction for pollutant removal.