Synthesis of photoluminescent N doped and S doped carbon graphene quantum dots with modified optical properties

• Published in: Journal of materials science. Materials in electronics 2023-10, Vol.34 (28), p.1955, Article 1955
• Main Authors: Khan, Salma, Narula, Anudeep Kumar
• Format: Article
• Language: English
• Subjects: Bimetals; Carbon; Characterization and Evaluation of Materials; Chemistry and Materials Science; Citric acid; Electrochemical impedance spectroscopy; Electrodes; Electrons; Graphene; Materials Science; Optical and Electronic Materials; Optical properties; Photoluminescence; Pyrolysis; Quantum dots
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-023-11363-0

Graphene quantum dots (GQDs) are a new class of materials that have replaced the conventional bimetallic dots with their unique properties. In the present study GQDs, N doped GQDs (N-GQDs) and S doped GQDs (S-GQDs) are synthesized by in-situ one step method of pyrolysis of citric acid (bottom up technique). The fabrication of florescent GQDs and doped GQDs with heteroatom N and S are evidently supported with transmission electron microscopy (TEM) and FT-IR. The mechanism of the photoluminescence in these quantum dots is investigated thorough the photoluminescence spectroscopy (PL) which was further reinforced by the electrochemical impedance spectroscopy (EIS) and with cyclic voltammetry. N-GQDs shows blue colored emission while S-GQDs shows relatively longer wavelength yellow green colored emission. Emission from the defective surface sites of the doped GQDs was confirmed from the proposed mechanism of PL of these dots.