Study of optical and thermal properties in nickel doped ZnS nanoparticles using surfactants

The presence of surfactants polyethylene glycol (PEG), polyvinyl pyrrolidone (PVP), sodium hexameta polyphosphate (SHMP) and tri-octyl phosphine oxide (TOPO) on the surface of Ni2+ doped ZnS (ZnS:Ni2+) nanoparticles resulted variation in their optical properties. The optical properties of each surfactant-capped ZnS:Ni2+ nanoparticles were investigated using UV–visible (UV–Vis) absorption and photoluminescence (PL) techniques. The absorption spectra and fluorescent emission spectra showed a significant blue shift compared to that of the bulk zinc sulfide. The effect of the optical properties in colloidal form (wet) and dry samples were investigated. Enhanced PL emission was observed for the dry samples at 80 °C. Thermal properties of the ZnS:Ni2+ was also studied using thermo gravimetric-differential thermal analysis (TG-DTA), Fourier transform infra-red spectrometer (FT-IR) and X-ray diffraction (XRD). The results are presented and discussed.

► Different concentrations of surfactants capped ZnS:Ni nanoparticles were synthesized.
► Optical properties of ZnS:Ni in wet and annealed samples were studied.
► Enhanced PL emissions were observed for dry samples.
► Stability of the ZnS:Ni nanoparticles were studied.