ZnS nanoparticles (NPs) are prepared by co-precipitation method using ethylene diamine tetra-acetic acid as a stabilizer and capping agent. The structural, morphological and optical properties of as-synthesized NPs are investigated using X-ray diffraction, scanning electron microscope, Fourier transform infrared spectroscopy, ultraviolet-visible (UV-Vis) absorption, and photoluminescence spectroscopy. The X-ray diffraction pattern exhibits a zinc-blended crystal structure at room temperature. The particle size was found to be in the range of 22.22 nm. The ultraviolet absorption spectrum shows the blue shift in the bandgap due to the quantum confinement effect. The photoluminescence spectrum of ZnS NPs shows a blue visible spectrum. The template of the cyclic voltammetry contour demonstrated a strong rate suggesting that the ZnS nanostructure electrode has a reduced polarization effect. The above studies have provided resplendent efficiency and proven that ZnS NPs can be used as a prominent material for supercapacitor applications.