However, at relatively higher Cr concentrations a slower red shift was shown by the doped nanoparticles. The UV-Visible absorption spectra showed blue shift which became even more pronounced in Cr doped ZnS nanoparticles. Fourier transfer infrared spectra confirmed the Zn-S stretching bond at 664 cm of ZnS in all prepared nanoparticles. X-ray diffraction analysis confirmed the absence of any mixed phase and the cubic structure of ZnS in pure and Cr doped ZnS nanoparticles. The structural, optical and magnetic properties of pure and Cr doped ZnS nanoparticles were studied at room temperature. Quantum size effects were observed in optical absorption studies while quenching of defect states on nanoparticles was improved with increase in starch addition as indicated by photoluminescence spectra.Įffect of Cr doping on structural and magnetic properties of ZnS nanoparticles Interaction between ZnS and starch was confirmed by Fourier transform infrared spectroscopy as well as Raman scattering studies. Transmission electron microscopic studies indicated that starch limits the agglomeration by steric stabilization. X-ray diffraction studies indicated that nanopowders obtained were polycrystalline possessing ZnS simple cubic structure. Microwave irradiation was used as heating source. Ramananda, D.įollowing a green synthesis method, zinc sulfide ( ZnS) nanoparticles were prepared by chemical co-precipitation technique using starch as capping agent. Investigations on structural and optical properties of starch capped ZnS nanoparticles synthesized by microwave irradiation method The photoluminescence spectra of pure ZnS nanoparticles showed an emission at 421 and 485nm which is blue emission which was originated from the defect sites of ZnS itself and also sulfur deficiency and when doped with Mn2+ an extra peak with high intensity was observed at 530nm which is nearly yellow-orange emission which isrelated to the presence of Mn in the host lattice. ZnS itself is a luminescence material but when we dope it with transition metal ion such as Mn, Co, and Cu they exhibits strong and intense luminescence in the particular region. The band gap values of pure and doped ZnS nanoparticles were calculated from UV-Visible absorption spectra. From SAED pattern we calculated lattice parameter of the samples which have close resemblance from that obtained from XRD pattern. TEM images did showed agglomeration of particles and SAED pattern obtained indicated polycrystalline nature. We confirmed doping of Mn in the host ZnS by EDAX whereas powder X-ray diffractogram showed the cubic zinc blende structure of all these samples. ZnS nanoparticles co-doped with different concentration (5,10,15%) of Mn were synthesized using polyvinylpyrrolidone (PVP) as a capping agent under microwave irradiation. Photoluminescence study of Mn doped ZnS nanoparticles prepared by co-precipitation methodĭeshpande, M. The stronger FL emission peaks of ZnS synthesized with starch, indicate a larger content of sulfur vacancies or defects than ZnS synthesized without starch.« less The chemical interaction exists between starch molecules and ZnS nanoparticles by hydrogen bonds. Sample without starch reveals irregular aggregates with particle size distribution of 0.5–2 μm. The results show that ZnS has polycrystalline spherical structure with the mean diameter of 130 nm. By X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible (UV–vis)more » spectroscopy and fluorescence (FL) spectrometer, their phases, crystalline lattice structure, morphologies, chemical and optical properties are characterized. The effects of different starch amounts on structure and properties of samples are investigated, and the forming mechanism of ZnS nanoparticles is discussed. Abstract: ZnS nanoparticles are fabricated via starch-assisted method. • ZnS spherical nano-structure can show blue emission at 460–500 nm. • The forming mechanism of ZnS nanoparticles. • The crystalline lattice structure, morphologies, chemical and optical properties of ZnS nanoparticles. ![]() ![]() Highlights: • ZnS spherical nanostructure was prepared via starch-assisted method. Tian, Xiuying, E-mail: Wen, Jin Wang, Shumei Starch-assisted synthesis and optical properties of ZnS nanoparticlesĭOE Office of Scientific and Technical Information (OSTI.GOV)
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