Synthesis of ZnS:Mn2+ and ZnS:Mn2+/ZnS core–shell nanoparticles using poly(methyl methacrylate)

The water-soluble and high-quality ZnS:Mn2+/ZnS core–shell nanoparticles were synthesized by chemical precipitation method in an air atmosphere. The poly(methyl methacrylate) (PMMA) was used as a surfactant. Structural, morphology and optical properties were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–visible absorption and photoluminescence spectrometer, respectively. The obtained particles were highly crystalline and monodisperse with an average particle size ranging from 3 to 6 nm. A typical plant-(leafs, stem, and roots) like structures were obtained by passivation of PMMA on ZnS:Mn2+ surface. The presence of ZnS shell on ZnS:Mn2+ surface was confirmed by XRD, TEM and EPR studies. Well-defined and very narrow size distributed core–shell nanoparticles were prepared by capping with PMMA molecules on ZnS:Mn2+/ZnS core–shell nanoparticles. The PMMA layer on ZnS:Mn2+/ZnS was also clearly identified in the TEM images.