Insights into enhanced peroxydisulfate activation with S doped Fe@C catalyst for the rapid degradation of organic pollutants

In this study, the S modified iron-based catalyst (S-Fe@C) for activating peroxydisulfate (PDS) was fabricated by heating the S-MIL-101 (Fe) precursor at 800 degrees C. The resulted S-Fe@C composite mainly consisted of carbon, Fe-0, FeS, FeS2, and Fe3O4 , and showed strong magnetism. Compared with Fe@C obtained from MIL-101 (Fe), the S-Fe@C exhibited much higher performance (1.5 times larger) on PDS activation and the S-Fe@C/PDS could rapidly degrade various organic pollutants in 5 min under the attack of the species of SO4 center dot-, O-1(2), electro-transfer and Fe(IV). The S element in enhancing the PDS activation mainly involved two mechanisms. Firstly, the doped S could speed up the electron transfer efficiency, resulting in a promotion on PDS decomposition; secondly, the S2- S-2(2-) or S-0 could achieve the circulation of Fe2+ and Fe3+, leading to the formation of non-radicals Fe(IV) and O-1(2) . (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

The S modified iron-based catalyst (S-Fe@C) was fabricated by heating the S-MIL-101 (Fe) precursor at 800 degrees C, showing higher performance in activating peroxydisulfate (PDS) and degrading various organic pollutants rapidly. The enhancement of PDS activation by the S element mainly involved two mechanisms, speeding up electron transfer efficiency and achieving the circulation of Fe2+ and Fe3+ to form non-radicals Fe(IV) and O-1(2).