Long-term effects of impurities on the particle size and optical emission of carbon dots
| Autor: | Deirdre M. O'Carroll, Nasir Javed |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Photoluminescence
Materials science General Engineering Analytical chemistry Quantum yield chemistry.chemical_element Bioengineering 02 engineering and technology General Chemistry Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Fluorescence Decomposition Atomic and Molecular Physics and Optics 0104 chemical sciences chemistry Transmission electron microscopy Impurity Astrophysics::Solar and Stellar Astrophysics General Materials Science Particle size 0210 nano-technology Carbon |
| Zdroj: | Nanoscale Advances. 3:182-189 |
| ISSN: | 2516-0230 |
| DOI: | 10.1039/d0na00479k |
| Popis: | Carbon dots (CDs) are fluorescent nanoparticles that exhibit strong photoluminescence (PL) emission throughout the visible range of the electromagnetic spectrum. Recent studies highlight the presence of fluorescent impurities in CD dispersions. Here, the long-term impact of these impurities on the stability of the physical and optical properties of CDs synthesized by the solvothermal method is studied. A significant increase in particle size is observed as a function of time after synthesis from transmission electron microscopy analysis of CDs. Furthermore, the quantum yield of blue PL emission, which is mostly caused by impurities that contain carboxyl groups, gradually decays from 30% to ∼3% over 13 weeks. The reduction in quantum yield is attributed to decomposition of impurities that, consequently, deposit on the particles and increase particle size. Finally, it is observed that the blue emission decreases considerably when CDs are properly purified and a solvent-dependent yellow emission arises. The yellow emission is almost negligible when CDs are dispersed in water; however, the intensity of yellow emission increases significantly when the concentration of ethanol is increased. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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