Green synthesis of carbon quantum dots from Sideritis vuralii and its application in supercapacitors

Quantum 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 prominent 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 symmetrical capacitor behaviors with 10.42 F/g charge, 8.26 F/g discharge capacitances. The green synthesized CQDs can be improved for supercapacitor applications.