Multicolor Nitrogen-Doped Carbon Quantum Dots for Environment-Dependent Emission Tuning
Dineshkumar Sengottuvelu1, Abdul Kalam Shaik2, Satish Mishra1
1Dave C. Swalm School of Chemical Engineering, 323 Presidents Circle, Mississippi State University, MS State, Mississippi 39762, United States.
ACS Omega
|August 15, 2022
Summary
Nitrogen-doped carbon quantum dots (NCQDs) synthesized via a hydrothermal method show bright, environment-dependent multicolor photoluminescence. These NCQDs overcome aggregation-caused quenching, enabling strong solid-state emission for optoelectronic applications.
Area of Science:
- Materials Science
- Nanotechnology
- Photochemistry
Background:
- Carbon quantum dots (CQDs) possess unique photoluminescence (PL) properties and environmental benignness, making them suitable for various applications.
- Aggregation-caused quenching (ACQ) effect limits the solid-state applications of most CQDs, as they become nonemissive when aggregated.
Purpose of the Study:
- To synthesize nitrogen-doped carbon quantum dots (NCQDs) using a facile one-pot hydrothermal method.
- To investigate the environment-dependent photoluminescence properties of NCQDs in various solvents, solid-state, and polymer matrices.
- To explore the potential of NCQDs in solid/gel state fluorescent displays and optoelectronic devices.
Main Methods:
- One-pot hydrothermal synthesis of NCQDs from citric acid and m-phenylenediamine.
- Investigation of NCQD photoluminescence in different solvents (e.g., 2-ethyl-hexanol) and solid states.
- Incorporation of NCQDs into PMMA-PnBA-PMMA copolymer gels to study fluorescence in polymer matrices.
Main Results:
- NCQDs exhibited bright, environment-dependent multicolor photoluminescence across the visible spectrum.
- NCQDs demonstrated excitation-dependent PL and solvatochromism.
- Strong solid-state emission centered at 568 nm was observed, overcoming the ACQ effect due to surface functional groups.
- NCQD-containing gels showed enhanced fluorescence compared to solutions, attributed to interactions with polar PMMA blocks.
Conclusions:
- The synthesized NCQDs overcome ACQ, enabling strong solid-state emission.
- NCQDs offer tunable multicolor emission, suitable for advanced fluorescent displays.
- This research paves the way for developing low-cost, large-scale multicolor phosphors for optoelectronics, sensing, and bioimaging.
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