Green Engineering and Sustainable Development of Nitrogen-doped Carbon Quantum Dots (MPE-NCQDs): A Correlative Study of Structure, Composition and Photophysical Properties
J. Environ. Nanotechnol., Volume 15, No 1 (March 2026) pp. 367-377
Abstract
A sustainable one-step microwave-assisted strategy is reported for the synthesis of nitrogen-doped carbon quantum dots (MPE-NCQDs) using malic acid as a bio-derived carbon precursor in the presence of polyvinylpyrrolidone and ethanolamine. The approach integrates rapid carbonization with in situ surface passivation and heteroatom incorporation, enabling controlled formation of emissive carbon nanostructures under mild processing conditions. The resulting MPE-NCQDs exhibit uniform nanoscale characteristics, good aqueous dispersibility, and stable photoluminescence, arising from the combined influence of carbon core structure and surface functional chemistry. Systematic structural and photophysical analyses reveal that emission behaviour is governed by the interplay between precursor chemistry, nitrogen configuration, and surface passivation, rather than by size effects alone. By correlating sustainable precursor design with microwave processing and structure–property relationships, this work addresses a key gap in the development of environmentally benign CQD systems. The findings highlight the potential of malic-acid-based, microwave-derived N-CQDs as versatile platforms for optoelectronic and sensing-related applications.
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