Optical properties of ZnS nanoparticles prepared by high energy ball milling

In this work, we synthesized zinc sulfide (ZnS) nanoparticles by the mechanochemical route using zinc acetate and sodium sulfide as source materials in a high energy planetary ball mill at rotation speed of 300 rpm with ball to powder ratio 5:1 for 30-120 min. Powder samples were collected at duration of 30 min for different analyses. The milled powders were washed with methanol to remove impurity and dried at 50 °C for 2 h. ZnS nanoparticles are characterized by X-ray diffraction, transmission electron microscopy, field-emission scanning electron microscopy, UV-vis-NIR spectrophotometry and fluorescence spectrophotometry. The crystallite size of synthesized ZnS nanoparticles is found to be approximately 2 nm. The optical band gap of the ZnS nanoparticles is found to be in the range of 4.71-5.17 eV. Room temperature photoluminescence (PL) spectra of the samples exhibit blue-light emission using UV excitation wavelength of 280 nm.