Solid-State Phosphors from Coal-Derived Carbon Quantum Dots
Anusuya Boruah1,2, Sarmistha Bora1, Ashutosh Thakur1,2
1Coal and Energy Division, CSIR-North East Institute of Science and Technology, Jorhat 785006, Assam, India.
ACS Omega
|July 24, 2023
Summary
This study presents a sustainable method for creating solid phosphors from coal-derived carbon quantum dots (CQDs). These novel CQDs exhibit excellent blue fluorescence and enable high-intensity white light emission in solid-state materials.
Area of Science:
- Materials Science
- Nanotechnology
- Chemistry
Background:
- Carbon quantum dots (CQDs) possess unique optical and chemical properties, leading to diverse applications.
- Expanding the utility of coal-derived CQDs into the solid state is crucial for broader technological integration.
- Developing sustainable synthesis methods for CQDs is an ongoing research priority.
Purpose of the Study:
- To develop a sustainable synthesis for solid-state phosphors using coal-derived carbon quantum dots (CQDs).
- To investigate the properties of CQDs integrated into organic (poly(vinyl alcohol)) and inorganic (silica) matrices.
- To explore the potential of these solid-state CQD materials for optical applications, including white light emission.
Main Methods:
- Eco-friendly ultrasonic-assisted wet oxidation for CQD synthesis.
- Fabrication of poly(vinyl alcohol)/CQD composite films and silica/CQD phosphors via sol-gel method.
- Comprehensive characterization of CQD structure, chemical properties, and fluorescence behavior.
Main Results:
- Two types of coal-derived CQDs were synthesized, exhibiting blue fluorescence with quantum yields of 8.9% and 14.9%.
- CQDs were found to be self-co-doped with nitrogen and sulfur heteroatoms.
- Solid-state fluorescence was confirmed in both PVA/CQD and SiO2/CQD matrices, with the latter achieving high-intensity white light emission.
Conclusions:
- Sustainable synthesis of solid-state phosphors from coal-derived CQDs is achievable using PVA and SiO2 matrices.
- Coal-derived CQDs retain their fluorescence properties in solid matrices and can be engineered for specific optical outputs.
- The developed SiO2/CQD phosphors demonstrate potential for advanced optical applications due to their white light emission properties.
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