Electronic structure modulation of covalent organic frameworks by single-atom Fe doping for enhanced oxidation of aqueous contaminants. (14th December 2019)

• Record Type: Journal Article
• Authors: Yao, Yunjin; Yin, Hongyu; Gao, Mengxue; Hu, Yi; Hu, Huanhuan; Yu, Maojing; Wang, Shaobin
• Is Part Of: Chemical engineering science. Volume 209(2019)
• Publication Date: 2019-12-14
• Subjects: Iron -- Covalent organic framework -- Peroxymonosulfate -- Organic Pollutant -- Single Atom; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; Chemical engineering; Periodicals; Electronic journals; 660
• DOI: 10.1016/j.ces.2019.115211
• Languages: English
• ISSNs: 0009-2509

Abstract

Graphical abstract: Highlights: Single-atom Fe confined into N-doped porous carbon was fabricated. COF provided active elements and formed well-dispersed and accessible active sites. Iron doping generated Fe-Nx active sites with electronic structure modulation. Fe@COF possessed superior activity, benefiting from abundant Fe-Nx active sites. 1 O2 and O 2 ∙ - were the dominant species in the Fe@COF/PMS system. Abstract: A strategy for confining single-atom Fe in porous carbon (Fe@COF) from covalent organic framework (COF) was proposed and the Fe@COF catalysts were tested as peroxymonosulfate (PMS) activators for organic pollutants abatement. Iron doping preferentially generated effective single-atom Fe-Nx active sites into the carbon framework with electronic structure modulation, endowing prominent catalytic properties. Both in-situ electron paramagnetic resonance spectrometry and quenching measurements revealed that singlet oxygen ( 1 O2 ) generated by the Fe@COF/PMS system was primarily responsible for organic degradation rather than sulfate and hydroxyl radicals. The abundant single-atom Fe-Nx active sites with optimized binding energy were found to successfully activate PMS to produce 1 O2, while the rich pyrrolic nitrogen may act as the adsorption site of organic molecules, giving rise to remarkable catalytic activity in a broad pH range. The present investigation offers a new strategy to the construction of various COF-immobilized catalysts for an efficient environmental cleanup.