Rhinestone sheet like carbon and metal oxide-based nanocomposites for flexible supercapacitor applications

The increasing thrust lies in developing a better electrode material for supercapacitor applications. Carbon and metal oxide-based nanocomposites are the latest trend in this research area. In the present work, we are proposing the synthesis of simple, eco-friendly and cost-effective reduced graphene oxide (rGO), naturally derived carbon dots (CDs), and zinc oxide (ZnO)-based rZD ternary nanocomposites. These nanocomposites have been synthesized using eco-friendly and accessible hydrothermal method at three different temperatures (i.e., 300, 400, and 500 degrees C) and accordingly named as rZD300, rZD400, and rZD500. Further, the morphological (scanning electron microscopy and transmission electron microscopy) characterization studies predicted that ZnO and CDs were attached on to the rGO nanosheets to form the rhinestone sheet like structures. In addition, the crystalline and structural properties have been examined using X-ray diffraction, Raman, X-ray Photoelectron Spectroscopy, and X-ray Absorption Spectroscopy. The electrochemical studies (cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopic) predicted that highest capacitance achieved was 796 F/g using 2 M H2SO4 electrolytic solution for rZD500 nanocomposite. Finally, 1.5 V prototype flexible Supercapacitors (FSC) have been also fabricated using carbon cloth substrate for rZD500nanocomposite.