This title appears in the Scientific Report :
2020
Please use the identifier:
http://dx.doi.org/10.1016/j.cej.2019.122296 in citations.
Wavelength-dependent effects of carbon quantum dots on the photocatalytic activity of g-C3N4 enabled by LEDs
Wavelength-dependent effects of carbon quantum dots on the photocatalytic activity of g-C3N4 enabled by LEDs
Although the photocatalytic activity of g-C3N4 can be evidently enhanced by implanting 0-dimensional (0D) carbon quantum dots (CQDs), the enhancement mechanism, especially the relationship between the role of CQDs and photo-excitation wavelength, remained largely unclear. Herein, 0D/2D CQDs/g-C3N4 h...
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Personal Name(s): | Di, Guanglan |
---|---|
Zhu, Zhiliang (Corresponding author) / Dai, Qi / Zhang, Hua / Shen, Xiaolin / Qiu, Yanling / Huang, Yingying / Yu, Jianan / Yin, Daqiang / Küppers, Stephan | |
Contributing Institute: |
Analytik; ZEA-3 |
Published in: | The chemical engineering journal, 379 (2020) S. 122296 -122308 |
Imprint: |
Amsterdam
Elsevier
2020
|
DOI: |
10.1016/j.cej.2019.122296 |
Document Type: |
Journal Article |
Research Program: |
Terrestrial Systems: From Observation to Prediction |
Publikationsportal JuSER |
Although the photocatalytic activity of g-C3N4 can be evidently enhanced by implanting 0-dimensional (0D) carbon quantum dots (CQDs), the enhancement mechanism, especially the relationship between the role of CQDs and photo-excitation wavelength, remained largely unclear. Herein, 0D/2D CQDs/g-C3N4 heterostructures were fabricated for sulfamethazine (SMZ) photodegradation under both polychromatic (simulated daylight, 380 ≤ λ ≤ 780 nm) and monochromatic light (395, 410, 425, 435, 455, 475 and 500 nm) emitting from wavelength-tunable LEDs. We confirmed the promotional role of CQDs as a donor-sensitizer-acceptor to facilitate the charge separation and enhance light absorption. Further investigation showed that CQDs even exerted opposite effects in g-C3N4 photocatalytic activity under different excitation wavelengths: i) inhibition (380 ≤ λ ≤ 410 nm), ii) transition (410 < λ ≤ 425 nm), and iii) promotion (425 < λ ≤ 780 nm). Such oscillating behavior was attributed to the competition between synergistic effect and down-conversion fluorescent property of CQDs. The inherently versatile role of CQDs was among the first revealed, which was largely ignored in previous studies. Moreover, water quality parameters (pH, HCO3−, Br−, Cl−, NO3−, and SO42−) showed complicated impacts, and potentially improved the photocatalytic performance in actual water matrices. This study is of referential significance for developing LED-based photocatalysis technology for water decontamination, especially when CQDs are incorporated to improve the performance. |