Degradation of organic pollutants by Fe/N co-doped biochar via peroxymonosulfate activation: Synthesis, performance, mechanism and its potential for practical application

By Lu Xu, Borui Fu, Yan Sun, P. Jin, X. Bai, Xin Jin, Xuan Shi, Yong Wang, S.Q. Nie. 2020

322 citations recorded by the source corpus.

Abstract This study shows that the simple pyrolysis of mixed sawdust, FeCl3 and dicyandiamide can produce Fe/N co-doped biochar (Fe-N-C) with great catalytic and separation performances. Fe-N-C had a larger specific surface area (215.25 m2/g), higher defective degree (ID/IG = 0.98) and more active species for PMS activation because of the synergy between Fe and N doping. Furthermore, graphitic N, pyridinic N, Fe-Nx, Fe2O3 and Fe0 were identified as the dominant reactive species contributing to the activation of PMS. As a result, the production of reactive oxidizing species (ROS), including both sulfate radical (SO4•−), hydroxyl radical (•OH) and singlet oxygen (1O2), in the Fe-N-C/PMS system was significantly promoted. As a result, Fe-N-C exhibited 37.07 and 6.04-fold higher reaction rates for activating peroxymonosulfate (PMS) to degrade bisphenol A (BPA) relative to the rates achieved by pristine biochar and nitrogen doped biochar, respectively. Moreover, the mineralization rate of BPA by the Fe-N-C/PMS system was 68.9%, which was much higher than that achieved by the pristine biochar/PMS and N-biochar/PMS systems. Chemical-quenching tests further suggested that SO4•− and •OH played dominant roles in the degradation of BPA under acidic and neutral conditions, while 1O2 played a dominant role under alkaline conditions. Furthermore, the potential of Fe-N-C to be used in practical applications was systematically evaluated in terms of its stability, separability and selectivity to organics; the effect of operating parameters was also studied. Generally, our study highlighted the great potential of Fe/N co-doped biochar and provided valuable insight into the synthesis of highly efficient carbon-based catalysts for environmental applications.

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

View Paper: https://www.semanticscholar.org/paper/db25c044d923cafb840a69ebe647b222c62a12ce