Study on the electrochemical performance of ZnO nanoparticles synthesized via non-aqueous sol-gel route for supercapacitor applications

Pure zinc oxide (ZnO) nanoparticles have been synthesized by non-aqueous sol-gel route and electrochemical properties were studied for pseudocapacitor applications. The structural, morphological and functional studies were done by XRD, SEM and FTIR respectively. The results showed that the synthesized nanoparticles have good crystallinity, phase pure hexagonal wurtzite structure with highly dispersed nanoparticles with crystallite size about 85 nm. UV-vis DRS spectroscopy results depict that the absorption wavelength gets red shifted. The electrochemical analysis was carried out in three electrode system with the potential window from -0.4 to +0.6V under 3M KOH aqueous electrolyte. The calculated specific capacitance is very much high about 776 F g(-1) at 4 A g(-1) current density with 98% capacity retention upto 2500 cycles. Electrochemical impedance spectrum exhibited low ESR value revealed the fast charge transfer kinetics with superior electrical conductivity. These enhanced electrochemical performance highlight the potential of ZnO electrode for the development of supercapacitor applications.