Comparative analysis of ZnO nanoparticle's specific capacitance in supercapacitors: The role of surfactant and stabilizing agent

Abstract

In this report, a facile synthetic solution combustion technique is used for the synthesis of cost-effective nanomaterials (Zinc Oxide) for high performance in supercapacitor applications. To synthesize Zinc Oxide (ZnO) nanoparticles, zinc nitrate hexahydrate is used as an oxidizer, and citric acid is taken as a fuel. Here, the products' properties can be controlled in surfactant (sodium dodecyl sulphate, SDS) and stabilizing agent (polyvinylpyrrolidone, PVP). The effect of the addition of these agents played a crucial role in determining the synthesized nanocomposites' crystallite size, optical absorption, and specific capacitance. The structural and morphological characterization was done using X-ray diffraction, UV-visible, Fourier-transform infrared spectroscopy, Scanning electron microscopy, and Transmission electron microscopy. The average crystallite sizes were 14 – 20 nm, with a hexagonal structure of ZnO identified from X-Ray diffraction analysis. Electrochemical analyses were measured in 6M KOH within the potential window of 0 – 0.5 V. The specific capacitance of the material synthesized with surfactant (SDS) and stabilizing agent (PVP) was found to be the highest (919 F/g at 2 mV/s) compared to other zinc oxide nanoparticles, reflecting the key role of SDS and PVP in electrochemical performance.