Lignin regulating the active sites and peroxymonosulfate activation capacities of iron incorporated 1D carbon nanofiber for efficient organic pollutant degradation

Abstract

In this study, 1D iron incorporated carbon nanofiber composite catalysts (PLCF-Fe) were prepared by pyrolyzing iron nitrate embedded polyacrylonitrile/lignin electrospun nanofiber. PLCF-Fe exhibited prominent peroxymonosulfate (PMS) activation capability for organic pollutant degradation, in which 1D structured carbon nanofiber effectively inhibited the aggregation of iron moieties. The introduction of lignin could modulate the oxidation capacities of the prepared PLCF-Fe through regulating both the graphitic degree as well as the oxygen-containing group distributions of the carbon nanofiber, and the crystalline phase composition of the iron compounds in PLCF-Fe. The existence of multiple active sites could concertedly trigger radical and non-radical PMS activation for high-efficient pollutant degradations, during which process negligible iron ions were leached. It was also found that pollutant degradation rate in PLCF-Fe/PMS system was correlated well with their highest occupied molecular orbital positions. Additionally, PLCF-Fe/PMS system could maintain conspicuous catalytic performance in a variety of water matrices with wide pH application range. This study provides an applicable structure and active sites regulating approach to prepare high-efficiency heterogeneous catalyst for PMS based Fenton-like organic decontamination processes.