Yazar "Baslak, Canan" seçeneğine göre listele
Listeleniyor 1 - 4 / 4
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Electrolyte performance of green synthesized carbon quantum dots from fermented tea for high-speed capacitors(Elsevier Science Sa, 2023) Baslak, Canan; Demirel, Serkan; Kocyigit, Adem; Erdal, Mehmet Okan; Yildirim, MuratIn recent years, obtaining carbon nanomaterials from natural products by natural methods has been among the most popular topics. The materials synthesized by this way have beneficial properties such as biocompatible, photostable and less harmful for environment. In this study, carbon quantum dots (CQDs) were synthesized by using fermented tea as a natural material and carbon source. The capacitor performance as an electrolyte was investigated with high-speed charge-discharge method as unusual in the literature. The characterizations of the CQDs were realized by HRTEM, XRD, XPS, UV-Vis absorption, and fluorescence spectroscopy techniques. The resulting particles have a size of about 10 nm according to HRTEM image. While the structural properties of the CQDs were confirmed by XRD and XPS, and optical behaviors were confirmed by UV-Vis and fluorescence spectroscopies. The electrochemical behavior of the obtained CQDs was tested as electrolyte material for capacitor applications. Experiments were carried out in three different operating potential windows in the 0-2 V range, and CQDs electrolytes exhibited high capacitive effect in symmetrical capacitors. However, the cyclic voltammetry (CV) analyses revealed that the CQDs electrolytes displayed a full supercapacitor electrolyte feature in the 0-0.5 V range. The CQDs electrolytes have a promising material for technological and industrial applications with their unique redox performance and high capacitive effect.Öğe Green synthesis capacitor of carbon quantum dots from Stachys euadenia(Wiley, 2024) Baslak, Canan; Demirel, Serkan; Dogu, Suleyman; Ozturk, Gulsah; Kocyigit, Adem; Yildirim, MuratCarbon quantum dots (CQDs) are a new type of carbon nanomaterial that has recently attracted great attention as a potential competitor to standard semiconductor quantum dots. There are various ways to synthesis CQDs, and one of harmless way is undoubtedly green synthesis. In this study, hydrothermal synthesis based on the green way was employed to synthesize CQDs. The CQDs were obtained using the green leaves of the Stachys euadenia plant extract, an endemic species located in Turkey. The CQDs were characterized by fluorescent and UV-Visible spectroscopy, and results confirmed blue emission (430-480 nm) and absorption around 280 nm. X-ray photoelectron spectroscopy (XPS) analysis revealed C=C, C-N and C-O interactions. X-ray diffractometer (XRD) patterns confirmed structure of carbon with a broad peak of (002) plane. High resolution tunneling electron microscopy (HRTEM) and dynamic light scattering (DLS) analysis was used to determine the shape and size of CQDs. The CQDs obtained from Stachys euadenia were employed as electrode materials for capacitor application, and they were tested in Swagelok-type cell by cyclic voltammetry (CV) measurements. CQD capacitors exhibited 2.12 F/g charge and 1.24 F/g discharge capacitances were obtained with similar to 58% coulombic efficiency rate for the first cycle. Results highlights that CQDs are synthesized successfully by green synthesis method and can be used for capacitor applications.Öğe Green synthesis of carbon quantum dots from Sideritis vuralii and its application in supercapacitors(Elsevier, 2023) Baslak, Canan; Ozturk, Gulsah; Demirel, Serkan; Kocyigit, Adem; Dogu, Suleyman; Yildirim, MuratQuantum dots have good optical and electrical behaviors and can be employed in solar cells, displays and supercapacitors. When new studies in nanoparticle as well as synthesis of quantum dots are examined, it can be seen that the interest in the green synthesis approach has increased. The green synthesis approach is so prom-inent due to an environmentally friendly method and does not contain toxic chemicals at the experimental stage. In this study, we used Sideritis vuralii (S. vuralii), which is endemic in Turkey, as a source of the green synthesis approach. We synthesized carbon quantum dot (CQDs) particles with the hydrothermal method from S. vuralii plant. We performed UV-Vis spectra, fluorescence spectra, XPS and DLS analyzes for the characterization of the CQDs. According to the size and characteristics results, the CQDs were successfully synthesized from the S. vuralii plant. Furthermore, we employed CQDs as electrode for capacitor applications, and cyclic voltammetry (CV) measurements were performed. The CV measurements indicated that CQDs electrodes have rechargeable sym-metrical capacitor behaviors with 10.42 F/g charge, 8.26 F/g discharge capacitances. The green synthesized CQDs can be improved for supercapacitor applications.Öğe Voltammetric determination of facilitated ion transfer across the water/1,2-dichloroethane interface(Pleiades Publishing Inc, 2014) Baslak, Canan; Atalay, TevfikThe facilitated transfer characteristics of Cd2+ ion by 4-morpholinoacetophenone-4-ethyl-3-thiosemicarbazone (MAPET) across water/1,2-dicholoroethane (1,2-DCE) interface and its electrochemical properties were investigated by voltammetric measurements. Cyclic voltammetry (CV) was employed to examine the transfer in the conditions of the ligand (organic phase) in excess and the obtained transfer peaks have reversible nature at different metal concentrations and scan rates. The dependence of the obtained half-wave transfer potential on MAPET concentration showed that the equilibrium is effectively displaced towards a 1: 3 (Cd2+: ligand) stoichiometry with an association constant of log beta (3) (0) = 12.96 +/- 0.09 for the Cd2+ ion, corresponding to the TIC/TID mechanism.
