Manipulating Charge Dynamics in Carbon Nitride by Carbon Dot Doping for Efficient Photocatalysis
Abstract Graphitic carbon nitride (g‐C3N4), a prominent metal‐free semiconductor photocatalyst, faces limitations due to its high exciton binding energy. While significant efforts have been focused on optimizing charge‐carrier processes, the interplay of exciton and free carrier in this system have...
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Wiley
2025-07-01
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| Series: | Advanced Science |
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| Online Access: | https://doi.org/10.1002/advs.202417390 |
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| author | Lingfeng Ouyang Maggie Ng Zhang‐Hong Zhou Hao Wu Man‐Chung Tang Season Si Chen |
| author_facet | Lingfeng Ouyang Maggie Ng Zhang‐Hong Zhou Hao Wu Man‐Chung Tang Season Si Chen |
| author_sort | Lingfeng Ouyang |
| collection | DOAJ |
| description | Abstract Graphitic carbon nitride (g‐C3N4), a prominent metal‐free semiconductor photocatalyst, faces limitations due to its high exciton binding energy. While significant efforts have been focused on optimizing charge‐carrier processes, the interplay of exciton and free carrier in this system have received less attention. Herein, this density‐functional theory (DFT) and time‐dependent DFT calculations demonstrate that carbon dot‐functionalized g‐C3N4 (g‐C3N4/CD), synthesized via a facile thermal polymerization, shifts the excited state from localized to charge transfer characteristics. The g‐C3N4/CD exhibits reduced exciton binding energy from 41.0 to 24.6 meV, as shown by temperature‐dependent photoluminescence spectroscopy. Particularly, g‐C3N4/CD‐10 (10 wt.% CD solution in precursors) achieves a 3‐fold increase in the photodegradation rate (k = 0.020 min⁻¹) of an emerging environmental pollutant, levofloxacin (LEV), under 10 W LED light. Enhanced photocatalytic performances correlate with optimized band structure and efficient charge transport, as confirmed by photophysical and photoelectrochemical analyses. Although the excited state lifetime in g‐C3N4/CD is slightly reduced compared to pristine g‐C3N4, photocatalytic activity remains unaffected, underscoring the critical role of charge excited state in enhancing photocatalytic efficiency. This work offers insights onto the potential of manipulating charge transfer excited state dynamics for improved g‐C3N4‐based photocatalysis in environmental applications. |
| format | Article |
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| institution | Kabale University |
| issn | 2198-3844 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | Wiley |
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| spelling | doaj-art-80c1bf172e664bdc81d7dbdbd9cb332d2025-08-20T03:30:48ZengWileyAdvanced Science2198-38442025-07-011225n/an/a10.1002/advs.202417390Manipulating Charge Dynamics in Carbon Nitride by Carbon Dot Doping for Efficient PhotocatalysisLingfeng Ouyang0Maggie Ng1Zhang‐Hong Zhou2Hao Wu3Man‐Chung Tang4Season Si Chen5Institute of Environment and Ecology Tsinghua Shenzhen International Graduate School Tsinghua University Shenzhen 518005 P. R. ChinaInstitute of Environment and Ecology Tsinghua Shenzhen International Graduate School Tsinghua University Shenzhen 518005 P. R. ChinaMacau Institute of Materials Science and Engineering (MIMSE) Faculty of Innovation Engineering Macau University of Science and Technology Taipa Macau 999078 P. R. ChinaMacau Institute of Materials Science and Engineering (MIMSE) Faculty of Innovation Engineering Macau University of Science and Technology Taipa Macau 999078 P. R. ChinaInstitute of Materials Research Tsinghua Shenzhen International Graduate School Tsinghua University Shenzhen 518005 P. R. ChinaInstitute of Environment and Ecology Tsinghua Shenzhen International Graduate School Tsinghua University Shenzhen 518005 P. R. ChinaAbstract Graphitic carbon nitride (g‐C3N4), a prominent metal‐free semiconductor photocatalyst, faces limitations due to its high exciton binding energy. While significant efforts have been focused on optimizing charge‐carrier processes, the interplay of exciton and free carrier in this system have received less attention. Herein, this density‐functional theory (DFT) and time‐dependent DFT calculations demonstrate that carbon dot‐functionalized g‐C3N4 (g‐C3N4/CD), synthesized via a facile thermal polymerization, shifts the excited state from localized to charge transfer characteristics. The g‐C3N4/CD exhibits reduced exciton binding energy from 41.0 to 24.6 meV, as shown by temperature‐dependent photoluminescence spectroscopy. Particularly, g‐C3N4/CD‐10 (10 wt.% CD solution in precursors) achieves a 3‐fold increase in the photodegradation rate (k = 0.020 min⁻¹) of an emerging environmental pollutant, levofloxacin (LEV), under 10 W LED light. Enhanced photocatalytic performances correlate with optimized band structure and efficient charge transport, as confirmed by photophysical and photoelectrochemical analyses. Although the excited state lifetime in g‐C3N4/CD is slightly reduced compared to pristine g‐C3N4, photocatalytic activity remains unaffected, underscoring the critical role of charge excited state in enhancing photocatalytic efficiency. This work offers insights onto the potential of manipulating charge transfer excited state dynamics for improved g‐C3N4‐based photocatalysis in environmental applications.https://doi.org/10.1002/advs.202417390carbon dotscharge transfer excited stateemerging contaminantsgraphitic carbon nitridephotocatalysis |
| spellingShingle | Lingfeng Ouyang Maggie Ng Zhang‐Hong Zhou Hao Wu Man‐Chung Tang Season Si Chen Manipulating Charge Dynamics in Carbon Nitride by Carbon Dot Doping for Efficient Photocatalysis Advanced Science carbon dots charge transfer excited state emerging contaminants graphitic carbon nitride photocatalysis |
| title | Manipulating Charge Dynamics in Carbon Nitride by Carbon Dot Doping for Efficient Photocatalysis |
| title_full | Manipulating Charge Dynamics in Carbon Nitride by Carbon Dot Doping for Efficient Photocatalysis |
| title_fullStr | Manipulating Charge Dynamics in Carbon Nitride by Carbon Dot Doping for Efficient Photocatalysis |
| title_full_unstemmed | Manipulating Charge Dynamics in Carbon Nitride by Carbon Dot Doping for Efficient Photocatalysis |
| title_short | Manipulating Charge Dynamics in Carbon Nitride by Carbon Dot Doping for Efficient Photocatalysis |
| title_sort | manipulating charge dynamics in carbon nitride by carbon dot doping for efficient photocatalysis |
| topic | carbon dots charge transfer excited state emerging contaminants graphitic carbon nitride photocatalysis |
| url | https://doi.org/10.1002/advs.202417390 |
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