Structural and optical studies of pHEMA encapsulated ZnS:Ni²⁺ nanoparticles

In this study, ZnS:Ni(2+) nanostructures have been synthesized through chemical precipitation method using poly (2-hydroxyethyl methacrylate) (pHEMA) as capping agent. The structural, morphological and optical properties at different pHEMA concentration of ZnS:Ni(2+) were studied by using X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), UV-Vis Spectroscopy (UV-Vis), fourier transform infrared spectroscopy (FT-IR), Photoluminescence (PL). The Average crystalline size of the nanoparticles was found to be in the range of ∼3.59-4.36 nm. The surface morphological analysis reveals that the pHEMA capped nanoparticles showed homogeneous smooth surface. HR-TEM analysis reminds the original size of pHEMA capped nanoparticles. The band gap investigation revealed the size dependent of quantum confined nanoparticles. The immobilized nanoparticles in pHEMA matrix were verified by FT-IR studies. Novel luminescence properties have been observed for uncapped and pHEMA capped ZnS nanoparticles. The optimal capping concentration was successfully determined and its influence on photoluminescence behavior has been thoroughly analyzed.