Sol gel synthesis of zinc oxide nanoparticles and their application as nano-composite electrode material for supercapacitor

Abstract

In the present study, synthesis of ZnO nanoparticles is reported using sol-gel method. Initially, Zinc acetate and Polyethylene glycol were used for the formation of Zn-alkoxide. Finally, sodium hydroxide converted this sol into Gel. Drying and calcination resulted in ZnO nanoparticles (NPs). The structural and morphological characterization of synthesized NPs were done X-ray diffraction (XRD), Transmission electron microscopy (TEM) and Selected area electron diffraction (SAED). The nano-composite is prepared by mixing ZnO nanoparticles with activated charcoal (AC) powder. Surface morphology of the prepared ZnO-AC nano-composite film was also studies by Scanning electron microscopy (SEM). Electrochemical double-layer capacitor (EDLC) Cell has been fabricated by ZnO-AC nano-composite as electrode material and 6 M KOH as an electrolyte. The electrochemical characterization techniques such as a. c impedance spectroscopy, cyclic voltammetry and galvanostatic charge discharge technique are used for the performance evaluation of fabricated supercapacitor cell. Higher specific capacitance of the order of 118.122 mF cm−2 and a very small variation in capacitance for higher scan rates and current density proved synthesized ZnO-AC (1:1) nano-composite as a promising electrode material for supercapacitor applications.