Luminescence properties of ZnS nanoparticles and porous nanospheres synthesized via co-precipitation and hydrothermal route

Abstract

ZnS nanoparticles were synthesized by hydrothermal and co-precipitation methods. The starting precursors were sodium thiosulfate and zinc chloride for the hydrothermal method; zinc acetate dihydrate and sodium polyphosphate for the co-precipitation method. Scanning electron microscopy (SEM) images of ZnS powder prepared by hydrothermal route show the co-existence of individual ZnS nanoparticles and microspheres formed by the nanoparticles. When acrylamide was added to the process, ZnS porous nanospheres were obtained. Structural properties of ZnS powder prepared by both methods were studied by means of X-ray diffraction (XRD) which revealed that ZnS nanoparticles has the cubic phase and the average size of ZnS nanocrystallites is in the range of 10 nm. Photoluminescence excitation (PLE) and photoluminescence (PL) spectra of ZnS powder synthesized by hydrothermal method indicated that the luminescence intensity of the ZnS nanoparticles was affected by reaction time and surfactant meanwhile a blueshift of about 8 nm compared to bulk ZnS was observed in PLE data of ZnS powder prepared by co-precipitation method, that indicates the quantum confinement effects. © 2011 The Surface Science Society of Japan.