Communication Dans Un Congrès Année : 2024

Advanced study of photoluminescent carbon quantum dots photophysical behavior

Résumé

In 2004, Xu et al. [1] made a breakthrough discovery regarding nanoparticles comprised of carbon that exhibit blue photoluminescence. These nanoparticles, known as carbon dots, are characterized by a 0D hybrid structure featuring clusters of sp2 carbon akin to graphene, enclosed within a shell of amorphous sp3 carbon exhibiting organic functional groups on its surface [2]. Carbon dots constitute a new and promising category of nanomaterials capable of bright fluorescence, biocompatibility and photostability [3]. However, the mechanisms governing their photoluminescent properties are still misunderstood [4]. Because of the challenges present in purification [5] and multi-components fluorescent behavior, the use of advanced spectroscopy techniques is required to pave the way toward new efficient synthesis and applications. We synthesize diverse carbon dot structures through bottom-up high-pressure methods using organic molecules as precursors. Optimal synthesis conditions such as pressure, temperature, and precursor selection, are determined from subsequent characterizations. Purification is either performed through thorough dialysis or silica column chromatography to separate nanoparticles from fluorescent precursors or molecular by-products and their structure is then determined through FTIR, Raman, XPS, and TEM imaging. Then, saturation fluorescence correlation spectroscopy (FCS) is used as a performant tool enabling us to determine the origin of fluorescence, i.e. the carbon dot or free molecular fluorophores. Using low-temperature (<10K) photoluminescence measurements on single carbon dots, we were also able to determine whether the fluorescence originated from the graphene core, functional groups, and surface defects, or from a molecular fluorophore trapped in the nanoparticles. The aim of the work presented here is to understand as precisely as possible the photophysical process of these new fluorescent nanoparticles, which could one day replace traditional semiconductor quantum dots. References: [1]Xu, X. et al.; J Am Chem Soc 2004, 126 (40), 12736–12737. https://doi.org/10.1021/ja040082h. [2]Mintz, K. J et al. Carbon 2021, 173, 433–447. [3]Tuerhong, M.; Xu, Y.; Yin, X.-B.; Chinese Journal of Analytical Chemistry 2017, 45 (1), 139–150. [4]Zhu, S.; Song, Y.; Zhao, X.; Shao, J.; Zhang, J.; Yang, B; Nano Res. 2015, 8 (2), 355–381. [5]Hinterberger, V. et al.; Nanoscale 2019, 11 (17), 8464–8474.

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Dates et versions

hal-04671017 , version 1 (13-08-2024)

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  • HAL Id : hal-04671017 , version 1

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Théo Duarte de Assuncao, Roy Konnoth-Ancel, Christophe Couteau, Jerome Plain, Julien Proust. Advanced study of photoluminescent carbon quantum dots photophysical behavior. NANOSEA 2024, Jul 2024, Marseille, France. ⟨hal-04671017⟩
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