Carbon nanodots revised
- Luminescent compounds obtained from the thermal reaction of citric acid and urea have been studied and utilized in different applications in the past few years. The identified reaction products range from carbon nitrides over graphitic carbon to distinct molecular fluorophores. On the other hand, the solid, non-fluorescent reaction product produced at higher temperatures has been found to be a valuable precursor for the CO2-laser-assisted carbonization reaction in carbon laser-patterning. This work addresses the question of structural identification of both, the fluorescent and non-fluorescent reaction products obtained in the thermal reaction of citric acid and urea. The reaction products produced during autoclave-microwave reactions in the melt were thoroughly investigated as a function of the reaction temperature and the reaction products were subsequently separated by a series of solvent extractions and column chromatography. The evolution of a green molecular fluorophore, namely HPPT, was confirmed and a full characterizationLuminescent compounds obtained from the thermal reaction of citric acid and urea have been studied and utilized in different applications in the past few years. The identified reaction products range from carbon nitrides over graphitic carbon to distinct molecular fluorophores. On the other hand, the solid, non-fluorescent reaction product produced at higher temperatures has been found to be a valuable precursor for the CO2-laser-assisted carbonization reaction in carbon laser-patterning. This work addresses the question of structural identification of both, the fluorescent and non-fluorescent reaction products obtained in the thermal reaction of citric acid and urea. The reaction products produced during autoclave-microwave reactions in the melt were thoroughly investigated as a function of the reaction temperature and the reaction products were subsequently separated by a series of solvent extractions and column chromatography. The evolution of a green molecular fluorophore, namely HPPT, was confirmed and a full characterization study on its structure and photophysical properties was conducted. The additional blue fluorescence is attributed to oligomeric ureas, which was confirmed by complementary optical and structural characterization. These two components form strong hydrogen-bond networks which eventually react to form solid, semi-crystalline particles with a size of similar to 7 nm and an elemental composition of 46% C, 22% N, and 29% O. The structural features and properties of all three main components were investigated in a comprehensive characterization study.…
Author details: | Volker StraussORCiDGND, Huize Wang, Simon DelacroixORCiD, Marc LedendeckerORCiD, Pablo WessigORCiDGND |
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DOI: | https://doi.org/10.1039/d0sc01605e |
ISSN: | 2041-6520 |
ISSN: | 2041-6539 |
Pubmed ID: | https://pubmed.ncbi.nlm.nih.gov/34094179 |
Title of parent work (English): | Chemical science |
Subtitle (English): | the thermal citric acid/urea reaction |
Publisher: | Royal Society of Chemistry |
Place of publishing: | Cambridge |
Publication type: | Article |
Language: | English |
Date of first publication: | 2020/07/17 |
Publication year: | 2020 |
Release date: | 2023/11/16 |
Volume: | 11 |
Issue: | 31 |
Number of pages: | 11 |
First page: | 8256 |
Last Page: | 8266 |
Funding institution: | Fonds der Chemischen IndustrieFonds der Chemischen IndustrieEuropean; Commission; Federal Ministry of Education and Research (BMBF)Federal; Ministry of Education & Research (BMBF) [03XP0265]; Max Planck; societyMax Planck SocietyFoundation CELLEX |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie |
DDC classification: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften |
Peer review: | Referiert |
Publishing method: | Open Access / Gold Open-Access |
DOAJ gelistet | |
License (German): | CC-BY - Namensnennung 4.0 International |