Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Radical and non-radical cooperative degradation in metal-free electro-Fenton based on nitrogen self-doped biochar

Zhang, Ting ; Sun, Lu ; Sun, Xiaohong ; Dong, Heng ; Yu, Han LU and Yu, Hongbing (2022) In Journal of Hazardous Materials 435.
Abstract

To achieve sustainable metal-free electron-Fenton, N self-doped biochar air-cathode (BCAC) was prepared by pyrolyzing coffee residues. During the pyrolysis process, the endogenous N transformed from edge-doping to graphite-doping. Particularly, N vacancies started to evolve when the peak temperature exceeded 700 °C. A high Tetracycline removal rate of 70.42% was obtained on the BCAC at the current density of 4 mA cm−2. Quenching tests incorporated with ESR spectroscopy were adopted to identify the specific oxidants produced on the cathode. The results showed that •OH (37.36%), •O2- (29.67%) and 1O2 (24.17%) played comparable role in the tetracycline removal, suggesting the coexist... (More)

To achieve sustainable metal-free electron-Fenton, N self-doped biochar air-cathode (BCAC) was prepared by pyrolyzing coffee residues. During the pyrolysis process, the endogenous N transformed from edge-doping to graphite-doping. Particularly, N vacancies started to evolve when the peak temperature exceeded 700 °C. A high Tetracycline removal rate of 70.42% was obtained on the BCAC at the current density of 4 mA cm−2. Quenching tests incorporated with ESR spectroscopy were adopted to identify the specific oxidants produced on the cathode. The results showed that •OH (37.36%), •O2- (29.67%) and 1O2 (24.17%) played comparable role in the tetracycline removal, suggesting the coexist of radical and non-radical oxidants in our electro-Fenton system. According to the structure characterization and the DFT calculation, graphitic N was suggested as the critical site for H2O2 generation, and both graphitic N and pyridinic N were electroactive sites for H2O2 activation to •OH. Graphitic N and N vacancies with stronger capabilities in O2 adsorption and electron-trapping were proposed as the electroactive sites for 1O2 and •O2- formation. This work predicts a novel electro-Fenton process with cooperative radical and non-radical degradation on N self-doped carbonaceous catalysts at a mild condition, which is extremely meaningful for boosting sustainable electro-Fenton technology.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Metal-free electro-Fenton, N self-doped biochar, N vacancy, Reactive oxygen species, Singlet oxygen
in
Journal of Hazardous Materials
volume
435
article number
129063
publisher
Elsevier
external identifiers
  • pmid:35650745
  • scopus:85129714821
ISSN
0304-3894
DOI
10.1016/j.jhazmat.2022.129063
language
English
LU publication?
yes
id
c75863b2-c2ca-4b76-841f-7dd0fbead49e
date added to LUP
2022-12-27 15:42:47
date last changed
2024-06-15 00:59:59
@article{c75863b2-c2ca-4b76-841f-7dd0fbead49e,
  abstract     = {{<p>To achieve sustainable metal-free electron-Fenton, N self-doped biochar air-cathode (BCAC) was prepared by pyrolyzing coffee residues. During the pyrolysis process, the endogenous N transformed from edge-doping to graphite-doping. Particularly, N vacancies started to evolve when the peak temperature exceeded 700 °C. A high Tetracycline removal rate of 70.42% was obtained on the BCAC at the current density of 4 mA cm<sup>−2</sup>. Quenching tests incorporated with ESR spectroscopy were adopted to identify the specific oxidants produced on the cathode. The results showed that •OH (37.36%), •O<sub>2</sub><sup>-</sup> (29.67%) and <sup>1</sup>O<sub>2</sub> (24.17%) played comparable role in the tetracycline removal, suggesting the coexist of radical and non-radical oxidants in our electro-Fenton system. According to the structure characterization and the DFT calculation, graphitic N was suggested as the critical site for H<sub>2</sub>O<sub>2</sub> generation, and both graphitic N and pyridinic N were electroactive sites for H<sub>2</sub>O<sub>2</sub> activation to •OH. Graphitic N and N vacancies with stronger capabilities in O<sub>2</sub> adsorption and electron-trapping were proposed as the electroactive sites for <sup>1</sup>O<sub>2</sub> and •O<sub>2</sub><sup>-</sup> formation. This work predicts a novel electro-Fenton process with cooperative radical and non-radical degradation on N self-doped carbonaceous catalysts at a mild condition, which is extremely meaningful for boosting sustainable electro-Fenton technology.</p>}},
  author       = {{Zhang, Ting and Sun, Lu and Sun, Xiaohong and Dong, Heng and Yu, Han and Yu, Hongbing}},
  issn         = {{0304-3894}},
  keywords     = {{Metal-free electro-Fenton; N self-doped biochar; N vacancy; Reactive oxygen species; Singlet oxygen}},
  language     = {{eng}},
  month        = {{08}},
  publisher    = {{Elsevier}},
  series       = {{Journal of Hazardous Materials}},
  title        = {{Radical and non-radical cooperative degradation in metal-free electro-Fenton based on nitrogen self-doped biochar}},
  url          = {{http://dx.doi.org/10.1016/j.jhazmat.2022.129063}},
  doi          = {{10.1016/j.jhazmat.2022.129063}},
  volume       = {{435}},
  year         = {{2022}},
}