Magnetic MoS2/Fe3O4 composite as an effective activator of persulfate for the degradation of tetracycline: performance, activation mechanisms and degradation pathways

Autor: Lanhe Zhang, Qi Zhang, Tengyue Chen, Changyao Wang, Chuan Xiao, Jingbo Guo, Xiangrui Pang, Shuhua Liu
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Water Science and Technology, Vol 89, Iss 7, Pp 1860-1878 (2024)
Druh dokumentu: article
ISSN: 0273-1223
1996-9732
DOI: 10.2166/wst.2024.076
Popis: The activated persulfate (PS) process could produce sulfate radical (SO4·-) and rapidly degrade organic pollutants. The application of Fe3O4 as a promising PS activator was limited due to the rapid conversion of Fe2+ to Fe3+ on its surface. Mo4+ on MoS2 surface could be used as a reducing site to convert Fe3+ to Fe2+, but the separation and recovery of MoS2 was complex. In this study, MoS2/Fe3O4 was prepared to accelerate the Fe3+/Fe2+ cycle on Fe3O4 surface and achieved efficient separation of MoS2. The results showed that MoS2/Fe3O4 was more effective for PS activation compared to Fe3O4 or MoS2, with a removal efficiency of 91.8% for 20 mg·L−1 tetracycline (TC) solution under the optimal conditions. Fe2+ and Mo4+ on MoS2/Fe3O4 surface acted as active sites for PS activation with the generation of SO4•−, •OH, •O2−, and 1O2. Mo4+ acted as an electron donor to promote the Fe3+/Fe2+ cycling and thus improved the PS activation capability of MoS2/Fe3O4. The degradation pathways of TC were inferred as hydroxylation, ketylation of dimethylamino group and C-N bond breaking. This study provided a promising activated persulfate-based advanced oxidation process for the efficient degradation of TC by employing MoS2/Fe3O4 as an effective activator. HIGHLIGHTS MoS2/Fe3O4 was an effective, recoverable PS activator for tetracycline degradation.; TC was removed by free radical and non-free radical degradation pathways.; Mo4+ promoted the regeneration of Fe2+ on the Fe3O4 surface.;
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