Indian Journal of Science and Technology

Abstract

Objective: To prepare the zinc oxide nanoparticles using the extract of Hyptis suaveolens leaf by adopting the green synthesis methods. The prepared ZnO nanoparticles along with the activated carbon nanocomposite electrode will be used to fabricate supercapacitor cell. Methods/statistical analysis: Nanoparticles of ZnO were prepared using the green synthesis method. The structural and molecular characterizations were carried out using conventional techniques. The particle size of nanoparticles along with its elemental composition was determined using TEM-SAED and its optical transparency was studied. Finally, the nanocomposite of ZnO and activated carbon is subjected to the electrochemical impedance spectroscopy for understanding its supercapacitor properties. Findings: Hyptis suaveolens leaf extract was used in the preparation of ZnO nanoparticles and TEM confirms that the particle size was in the range of 10 and 200 nm. An absorption peak at 376 nm was observed from the UV spectroscopy, and the sample is transparent in the visible region. The capacitance value of the prepared sample is estimated to be 184.8 F/cm2 at 5 mV/sec. Applications/improvements: Nanocomposites of ZnO and activated carbon with different mass ratios (1:1 to 1:3) were subjected to electrochemical impedance measurement, and from the estimated capacitance value (184.8 F/cm²) it was found to be a potential candidate for the supercapacitor application. 
Keywords: Hyptis suaveolens, Nano-Zinc Oxide, Supercapacitor, TEM, XRD