Tuning the luminescence of nitrogen-doped graphene quantum dots synthesized by pulsed laser ablation in liquid and their use as a selective photoluminescence on–off–on probe for ascorbic acid detection

Autor: I.C. Novoa-de Leon, Jacob Johny, Selene Sepulveda-Guzman, Sadasivan Shaji, S. Carranza-Bernal, I. Mendivil, Sofia Vazquez-Rodriguez, Nora A. Garcia-Gomez
Rok vydání: 2019
Předmět:
Zdroj: Carbon. 150:455-464
ISSN: 0008-6223
DOI: 10.1016/j.carbon.2019.05.057
Popis: In this work, nitrogen-doped graphene quantum dots (N-GQDs) were synthesized by pulsed laser ablation in liquid using Nd:YAG laser (532 nm). Graphite target was ablated in dimethylformamide, as solvent and nitrogen source, and the microstructure as well as optical properties of N-GQDs were studied. The N-GQDs structure consists of a graphitic core with oxygen and nitrogen functionalities and particle size about 3 nm, as demonstrated by X-ray photoelectron spectroscopy, Raman spectroscopy and transmission electron microscopy. The as-prepared N-GQDs structure was modified by solvothermal treatment at 65, 90 and 120 °C reducing the oxygen functional groups, adding nitrogen and restoring the π-conjugated structure of N-GQD. The N-GQDs exhibit UV–Vis absorption spectrum with the characteristic π-π* and n – π* electronic transitions of the GQDs with a large amount of oxygen and nitrogen functionalities. These N-GQDs exhibited a visible light photoluminescence centered at 486 nm upon an excitation of 410 nm and the photoluminescence intensity enhanced up to 4.05% of quantum yield after solvothermal treatment. The N-GQDs dispersion was used for selective detection of ascorbic acid, through a signal-off and signal-on system. The results show the use of N-GQDs as a competent photoluminescence sensor for metal ions and ascorbic acid.
Databáze: OpenAIRE
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