Zhu, Lingli;
Shen, Dekui;
Zhang, Huiyan;
Luo, Kai Hong;
Li, Chong;
(2023)
Fabrication of Z-scheme Bi7O9I3/g-C3N4 heterojunction modified by carbon quantum dots for synchronous photocatalytic removal of Cr (VI) and organic pollutants.
Journal of Hazardous Materials
, 446
, Article 130663. 10.1016/j.jhazmat.2022.130663.
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Abstract
Chromium(VI) (Cr(VI)), a highly toxic metal ion, generally co-exists with organic pollutants in industrial effluents. The clean and effective technology for water purification is an imperative issue but still a challenging task. A series of Bi7O9I3/g-C3N4 (BOI/CN) composites modified by lignin-derived carbon quantum dots (CQDs) were fabricated by hydrothermal method and applied for synchronous photocatalytic removal of Cr (Ⅵ) and levofloxacin (LEV). With the modification of CQDs in BOI/CN heterojunction, the 0.5-CQD/BOI/CN photocatalyst (0.5% content of CQDs) exhibited stronger light-harvesting capacity, more efficient charge separation, and faster electron transfer. Compared to those of BOI (51.2%), CN (36.8%), and BOI/CN (74.4%), the photoreduction efficiency of Cr(VI) reached up to 100% by 0.5-CQD/BOI/CN under 60 min of light irradiation, together with 94.8% degradation efficiency of LEV. The degradation of LEV was dominantly controlled by active species (•OH and •O2−) identified by electron paramagnetic resonance analysis and free radical trapping experiments. The intermediates of LEV were determined by LC-MS and the possible degradation pathway was speculated in combination with density functional theory calculation, involving defluorination, decarboxylation, quinolone rings opening, and piperazine moieties oxidation reactions. This work provides an advanced strategy for the fabrication of high-efficiency CQDs-based Z-scheme photocatalysts for environmental remediation.
| Type: | Article |
|---|---|
| Title: | Fabrication of Z-scheme Bi7O9I3/g-C3N4 heterojunction modified by carbon quantum dots for synchronous photocatalytic removal of Cr (VI) and organic pollutants |
| Location: | Netherlands |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.jhazmat.2022.130663 |
| Publisher version: | https://doi.org/10.1016/j.jhazmat.2022.130663 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Synchronous photocatalytic removal, Levofloxacin, Cr(VI), Lignin-derived carbon quantum dots, Heterojunction |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Mechanical Engineering |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10166769 |
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