Lignin engineered preparation of one dimensional Fe3O4@C and Fe3C@C Fenton-like catalysts derived from MIL-88B(Fe) anchored electrospun nanofiber: Fe3C with high activity and high stability for organic pollutant degradation

In this study, a series of carbon nanofiber (CNF) based one-dimensional catalysts were prepared by pyrolyzing MIL-88B(Fe) anchored PAN/lignin electrospun nanofibers, which were then employed to activate peroxymonosulfate (PMS) for bisphenol A (BPA) degradation. The results indicated that adjusting the lignin content in nanofiber precursor could engineer the crystalline phase of iron compounds in the catalysts, as well as their catalytic activity and stability. Specifically, the precursor with lower lignin content was converted into Fe 3 O 4 loaded CNF (P2L1-Fe-C), whereas Fe 3 C loaded CNF was obtained (P1L1-Fe-C) by increasing lignin content to 50 wt% in the nanofiber precursor. Having multiple Fe valence states within Fe 3 C which facilitated internal electron transfer, P1L1-Fe-C exhibited high catalytic activity with high stability and low iron ion leaching when activating PMS for BPA degradation. P1L1-Fe-C/PMS system could produce more kinds of active species including hydroxyl radical (•OH) and multiple non-radical species like singlet oxygen ( 1 O 2 ), high-valent iron-oxo species, and electron transfer process. Comparatively, P2L1-Fe-C/PMS system was only able to produce •OH and 1 O 2 . The existence of more BPA degradation pathways resulted in enhanced resistance of P1L1-Fe-C/PMS system towards various environmental interferences. This study inspires a new thinking of developing iron based Fenton-like catalyst with tunable crystalline phases through precursor recipe regulation, achieving both high activity and stability. Download: Download high-res image (225KB) Download: Download full-size image