Synthesis and characterization of CeSuperscript3

Authors: N Shanmugam S Cholan G Viruthagiri R Gobi N Kannadasan

Publish Date: 2013/04/02

Volume: 4, Issue: 3, Pages: 359-365

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Abstract

Ceriumdoped zinc sulfide nanorods with flowershaped morphology have been successfully synthesized in air atmosphere through simple chemical precipitation method The incorporation of Ce3+ was confirmed by Xray diffraction and energydispersive spectrum The doping of Ce3+ ions has significant influence on the optical properties of the synthesized rods UV–Vis absorption spectroscopy measurements have shown that the absorption peak of doped ZnS was red shifted compared to undoped ZnS Photoluminescence measurements reveal that luminescence intensity of Ce3+ was enhanced considerably by the energy transfer from ZnS The existence of functional groups was identified using Fourier transform infrared spectrometer Field emission scanning electron microscope results show a uniform growth pattern of the nanorods with flowerlike structure High resolution transmission electron microscopy results showed that the doped ZnS nanocrystals are composed of uniform nanorods with average diameter of 22 nm and length of 140 nm The thermal stability of the nanorods was confirmed using thermo gravimetric and differential thermal analysisIn the modern scientific era optical properties of doped semiconductor nanoparticles have shown great impact as their electronic structure and electro magnetic fields are drastically modified due to quantum confinement effects Tailoring the color output of nanomaterials has been playing an important role for their applications as light emitting displays field emitters Fang et al 2007 Bando et al 2007 lasers sensors Fang et al 2009 and optoelectronic devices to multiplexed biological labeling Torimoto et al 2007 Yu et al 2010 The luminescence properties of ZnS nanoparticles have been tuned by doping with varies transition metals and rareearth metals Manzoor et al 2004 Hu and Zhang 2006 Kim 2009 Ageeth and Meijerink 2001 Since ZnS has wide band gap of 368 eV at room temperature its nanocrystals are the suitable host materials for the doping elements such as RE and transition metal ions which are optically and magnetically active Rareearth ions are categorized by group of elements known as the lanthanides and are most stable in their triply ionized form Furthermore ZnS is one of the eco friendly materials the REdoped ZnS nanocrystals can be used in producing efficient phosphor materials with a gamut of colors Bhargava 1996 ZnS host is able to produce red blue and green luminescence due to various RE ion dopants So far different synthesis routes have been suggested for the preparation of REdoped ZnS nanorods under low temperature and in particular the effect of dopant on the structures and optical properties are limited Wang and Fan 2006 In this paper we have attempted with a simple chemical precipitation method to prepare the Ce3+doped flowershaped ZnS nanorods From this method ceriumdoped nanorods of ZnS with flowerlike morphology have been obtainedZinc acetate dihydrate ZnCH3COO2·2H2O thiourea NH2CSNH2 ceriumIIIchloride hepta hydrateCeCl3·7H2O were purchased from Merck All chemicals were used as received since they were of analytical regent grade with 99  purity The glass wares used in this experimental work were acid washed Ultrapure water was used for all dilution and sample preparationFor the synthesis of Ce3+doped ZnS nanorods 3 g 035 M of zinc acetate ZnCH3COO2·2H2O in 40 ml of deionized water–ethanol matrix equal volume and an appropriate amount of cerium in 10 ml aqueous were mixed drop by drop Then 3 g 1 M of thiourea NH2CSNH2 in 40 ml of deionized water–ethanol matrix was added drop by drop to the above mixture The entire mixture was stirred magnetically at 80 °C until the homogeneous solution was obtained Finally the product was dried in a hot air oven at 120 °C for 2 h A similar method of preparation without the addition of cerium was used to synthesize undoped ZnS nanocrystalsThe Xray diffraction XRD patterns of the powdered samples were recorded using X′ PERT PRO diffractometer with CuKα radiation λ = 15406 Å The crystallite size was estimated using the Scherrer equation The optical absorption spectra of all the samples in deionized water were recorded using LAMDA 25 PERKIN ELMER spectrometer Fluorescence measurements were performed on a VARIAN spectrophotometer The FTIR spectra were recorded from a SHIMADZU8400 spectrometer using KBr pellet technique The morphology of the product was observed by a HITACHI S4700 field emission scanning electron microscope FESEM Energydispersive spectrum EDS measurement was carried out with the EDS arrangement enclosed with HITACHI S4700 FESEM Highresolution transmission electron microscopy HRTEM analysis was performed using JEOL 3010 HRTEM to study the morphology and size of the nanocrystals Thermo gravimetric analysis TGA and differential thermal analysis DTA studies have been performed using Perkin Elmer Diamond TGA/DTA instrument at a heating rate of 20 °C/min in air

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