Visible-light-driven photocatalytic degradation of ofloxacin by BiOBr nanocomposite modified with oxygen vacancies and N-doped CQDs: Enhanced photodegradation performance and mechanism.
In: Chemosphere, Jg. 307 (2022-11-21), S. N.PAG
academicJournal
Zugriff:
The rapid recombination of photogenerated carriers and weak light absorption capacity are two major challenges for bismuth-based photocatalysts. Here, N -CQDs/BiO 1-x Br micro-flower photocatalysts with the visible-light activity were fabricated through the ethylene glycol solvothermal method for the first time, and oxygen vacancies (OVs) and N -doped carbon quantum dots (N -CQDs) were simultaneously introduced on the surface of BiOBr. OVs were introduced to form defective BiOBr (BiO 1-x Br). N -CQDs and BiO 1-x Br formed a strong binding effect. Then, the composition, morphology, crystal structure and photoelectric property of photocatalysts were studied, and the mechanism and pathway of ofloxacin (OFL) photodegradation were studied. N -CQDs/BiO 1-x Br-4 was a micro-flower composed of nanosheets with a thickness of about 60 nm, this structure produced multiple light reflections. Photoelectrochemical analysis confirmed that the synergistic effect of OVs and N -CQDs significantly promoted the electron-hole separation (3 times vs BiOBr) and enhanced the light absorption range (Eg = 2.96 eV vs 3.24 eV). Meanwhile, the removal rate of OFL by N -CQDs/BiO 1-x Br-4 was 6 times higher than that by BiOBr (K obs of N -CQDs/BiO 1-x Br-4 was 32 times higher than that of BiOBr). Electron spin resonances analysis and radical quenching experiments showed that ·O 2 − and h+ played dominant roles in the OFL photodegradation system, and their contribution rates were 89.84% and 70.31%, respectively. There were main degradation pathways for OFL, including oxidation, dealkylation, hydroxylation and decarboxylation. This study explored the synergistic and complementary effects between OVs and N -CQDs, and provided a promising strategy for the photodegradation of toxic antibiotics by visible-light-driven photocatalysts. [Display omitted] • N -CQDs/BiO 1-x Br was synthesized by the ethylene glycol solvothermal method. • The synergistic mechanism of oxygen vacancies and N -CQDs was proposed. • N -CQDs played a major role in improving the efficiency of photocarrier separation. • O 2 − and h+ were determined to be the dominant species for the degradation of ofloxacin. [ABSTRACT FROM AUTHOR]
Titel: |
Visible-light-driven photocatalytic degradation of ofloxacin by BiOBr nanocomposite modified with oxygen vacancies and N-doped CQDs: Enhanced photodegradation performance and mechanism.
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Autor/in / Beteiligte Person: | Zhang, Zijing ; Wang, Yang ; Gao, Peng ; Feng, Li ; Zhang, Liqiu ; Liu, Yongze ; Du, Ziwen |
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Zeitschrift: | Chemosphere, Jg. 307 (2022-11-21), S. N.PAG |
Veröffentlichung: | 2022 |
Medientyp: | academicJournal |
ISSN: | 0045-6535 (print) |
DOI: | 10.1016/j.chemosphere.2022.135976 |
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