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    Graphene quantum dots prepared from dried lemon leaves and microcrystalline mosaic structure
    (Wiley, 2021) Kir, Sifa; Dehri, Ilyas; Onal, Yunus; Esen, Ramazan
    The aim of this study is to obtain graphene quantum dots (GQDs) by using Citrus limonum leaves grown in Adana Province, Mediterranean region. Thus, dried Citrus limonum leaves were subjected to carbonization at temperatures of 200, 275, 350, 425 and 500 degrees C and 90, 180, and 270 min respectively at each temperature. Characterization of the material obtained at the end of the process was determined by using X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), fluorescence spectroscopy, elemental analyzer, scanning electron microscopy (SEM), ultraviolet (UV)-visible, UV-A and UV-C lamps. It was determined that the samples obtained in the carbonization process carried out at 350 and 425 degrees C for 3 h made blue colored fluorescence. The results of the experiments completed for characterization analysis verified the GQDs and mosaic crystal structure compared to the literature. It was observed that the GQDs obtained at 350 degrees C for 3 h had maximum fluorescence properties. Radical changes at the sample matrix was observed when carbonization temperature changed from 350 degrees C to 425 degrees C.
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    The investigation of structural alteration of raw materials used to attain graphene quantum dots in different prolysis conditions
    (Elsevier, 2022) Kir, Sifa; Dehri, Ilyas; Onal, Yunus; Esen, Ramazan; Basar, Canan Akmil
    Graphene quantum dots which is one of the carbon allotrope become widespread an industrial usage due to the unique optical and electrical properties. Graphene Quantum Dots (GQDs) is obtained from the materials such as graphite, glycine, alginate, glucose whose structure contains carbon atoms. In this study, molasses that are used to attain GQDs are carbonized at the temperature of 200, 250, 300, 350 and 400 degrees C for 2 h. The DTA method was used to determine the melting temperature of the molasses. In order to determine the elemental and optical properties of the obtained graphene quantum dots particles, XRD, SEM, Elemental Analysis, Fluorescence Spectrometry techniques and UV-Visible Spectroscopy are used. Mass loss values was also determined and studied its effects were the outcome. The results obtained from these techniques show that the material obtained from the molasses is GQDs.