Peroxymonosulfate activation for pollutants degradation by Fe-N-codoped carbonaceous catalyst: Structure-dependent performance and mechanism insight

By Yangke Long, Yixuan Huang, Hui Wu, Xiaowen Shi, Ling Xiao. Chemical Engineering Journal, 2019

235 citations recorded by the source corpus.

Abstract In this study, Fe-N-codoped carbonaceous catalysts (Fe-N-C-x) with different structures including one-dimensional carbon nanotubes (1D CNTs) and two-dimensional porous carbon sheets (2D NC) to three-dimensional carbon nanotubes/porous carbon sheets composites (3D CNTs/NC) were systematically synthesized and applied as peroxymonosulfate (PMS) activators. It was found that the Fe-N-C-x catalysts exhibited structure-dependent catalytic performance, following the order of 2D NC > 3D CNTs/NC > 1D CNTs, and also substrate-dependent degradation performance that the reaction kinetics varied greatly for different organic pollutants. Benefiting from the unique structure characteristic and high density of active sites, 2D Fe-N-C-1 showed far superior catalytic performance than the generally used carbocatalysts with negligible Fe leaching. Besides, various influential factors affecting the catalytic performance were systematically investigated. Fe-N-C-1 showed high catalytic efficiencies toward a broad spectrum of organic pollutants, and it was confirmed that both radical and non-radical degradation pathways existed during pollutants degradation. The competitive radical quenching tests and electron paramagnetic resonance measurements verified that the superoxide anion radical ( O 2 Â · - ) was the primary reactive oxidized species for degradation of p-chlorophenol (4-CP). The chronoamperometry analysis demonstrated that Fe-N-C-1 facilitated the electron transfer from 4-CP to PMS, resulting in the degradation of 4-CP through a non-radical mechanism. Our result not only reveals the structure-dependent PMS activation performance of transition-metal and nitrogen codoped carbocatalysts but also provides solid evidence that the defect-rich carbon materials with amorphous carbon and partial graphitic structure also favor the electron transfer mechanism.

Subfields: Biomedical Engineering, Renewable Energy, Sustainability and the Environment, Water Science and Technology

View Paper: https://www.semanticscholar.org/paper/942ab9bf7bca97ef670cf6d558a50bb2eae6efc6