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Study of Photocatalytic Behavior of Photochemical Doped TiO2 Nanoparticles with In-V Synthesized by Sol-gel and Hydrothermal Methods  [cached]
Hamadanian Khozani M.,Reisi-Vanani A.,Razi P.,Hoseinifard S.
Proceedings of the International Conference Nanomaterials : Applications and Properties , 2012,
Abstract: Indium- vanadium doped with different molar percent (0.05-1%) was prepared by photochemical reduction method on pure TiO2 nanoparticles synthesized by sol –gel and hydrothermal process. XRD, FT-IR, TEM, SEM and EDX analysis were done for characterized nanoparticles and methyl orange (MO) was used as an environmental pollutant to verify photocatalytic effect of synthesized particles under visible and UV lamps. Result of tests was showed that In-V doping restrain from crystal growth, that only hydrothermal TiO2 particles with binary doped 0.2% molar of In-V can improve photocatalytic activity compared to sol-gel nanoparticles. Pure TiO2 prepared by hydrothermal and sol-gel processes were calcined at 300,400,450,550 oC for 3h and 500o C for 2h, respectively.
Fabrication and Optical Behaviors of Core–Shell ZnS Nanostructures  [cached]
Yang Zai-Xing,Zhong Wei,Deng Yu,Au Chaktong
Nanoscale Research Letters , 2010,
Abstract: Novel core–shell nanostructures comprised of cubic sphalerite and hexagonal wurtzite ZnS have been synthesized at 150°C by a simple hydrothermal method. The results of HR-TEM and SAED investigation reveal that the cores of hexagonal wurtzite ZnS (ca. 200 nm in average diameter) are encapsulated by a shell of cubic sphalerite ZnS. The FE-SEM image of the nanomaterials shows a surface tightly packed with nanoparticles (<10 nm in size). The optical properties of the fabricated material have been studied in terms of ultraviolet–visible absorption and photoluminescence. Furthermore, a possible mechanism for the fabrication of the core–shell nanostructures has been presented.
Hydrothermal Synthesis of Nanoclusters of ZnS Comprised on Nanowires  [PDF]
Zafar Hussain Ibupoto,Kimleang Khun,Xianjie Liu,Magnus Willander
Nanomaterials , 2013, DOI: 10.3390/nano3030564
Abstract: Cetyltrimethyl ammonium bromide cationic (CTAB) surfactant was used as template for the synthesis of nanoclusters of ZnS composed of nanowires, by hydrothermal method. The structural and morphological studies were performed by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) techniques. The synthesized ZnS nanoclusters are composed of nanowires and high yield on the substrate was observed. The ZnS nanocrystalline consists of hexagonal phase and polycrystalline in nature. The chemical composition of ZnS nanoclusters composed of nanowires was studied by X-ray photo electron microscopy (XPS). This investigation has shown that the ZnS nanoclusters are composed of Zn and S atoms.
Photoluminescence and EPR Studies of ZnS Nanoparticles Co-Doped With Mn and Te  [PDF]
A. Divya,B.K. Reddy,S. Sambasivam,P. Sreedhara Reddy
Journal of Nano- and Electronic Physics , 2011,
Abstract: ZnS nanoparticles Co-doped with Mn and Te (x = 0.05 and 0.10) have been synthesized for the first time by chemical co-precipitation method, thiophenol is used to passivate the surface of the particles. The as-prepared samples were amorphous in nature. Nanocrystallinity was induced after calcining the samples at 300oC/2hrs. The obtained nanoparticles were subjected to X-ray diffraction (XRD), Energy Dispersive Analysis of X-rays (EDAX), Transmission Electron Microscopy (TEM), Photoluminescence (PL) and Electron Paramagnetic Resonance (EPR) studies. All the samples exhibited cubic structure and the particle size was found to be 3-5 nm. EDAX revealed that the compositions did not deviate much from the target compositions. The photoluminescence studies showed emission in the red region and the emission wavelength is varied with composition. The Electron Paramagnetic Resonance (EPR) spectra showed paramagnetic nature of the samples at room temperature. EPR and PL results were quite consistent with each other.
X-ray excited luminescence property of ZnS:Cu,Tm fine particles synthesized by hydrothermal method
水热法制备ZnS:Cu,Tm超细X射线发光粉

Xin Mei,Cao Wang-He,
新梅
,曹望和

物理学报 , 2010,
Abstract: 研究了水热法合成的ZnS: Cu,Tm超细X射线发光粉及其光致发光(PL)和X射线激发发光(X-ray excited luminescence,XEL)光谱特性.200 ℃水热处理12 h直接合成样品的纳米晶粒径约15 nm,尺寸分布窄,分散性好,具有纯立方相的类球形结构.氩气保护下900 ℃退火1 h后的样品存在一定的团聚,但团聚后尺寸为200—600 nm,为超细X射线发光粉,此时样品为纯六方相的类球形为主的结构.所有样品的PL和XEL光谱均为宽带谱.水热法直接合成样品的XEL强度最强时,样品的Cu/Zn,Tm/Cu比值分别为3×10-4和2.在此比值条件下,900 ℃退火1 h样品的XEL发光最强,此时其两个峰值分别位于453,525 nm.发光强度增强的同时粒径很小,对提高成像系统分辨率非常有意义.通过比较PL光谱与XEL光谱特性,讨论了PL和XEL光谱的发光机理和其不同的激发机理.
Synthesis of ZnS:Mn2+ and ZnS:Mn2+/ZnS core–shell nanoparticles using poly(methyl methacrylate)
G. Murugadoss
Applied Nanoscience , 2013, DOI: 10.1007/s13204-012-0157-x
Abstract: 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.
Effect of manganese doping on the photoluminescence characteristics of chemically synthesized zinc sulfide nanoparticles
A. K. Kole,P. Kumbhakar
Applied Nanoscience , 2012, DOI: 10.1007/s13204-011-0036-x
Abstract: The studies on luminescent II-VI semiconducting nanomaterials have attracted widespread attention recently, due to their potential applications in optoelectronic and biophotonic devices. Amongst other II-VI semiconductor nanoparticles (NPs), Mn2+-doped ZnS NPs having large exciton binding energy and wide direct band gap at room temperature have drawn considerable attention for exploring its interesting optical properties. However, in this report, water-soluble Mn2+-doped ZnS (ZnS:Mn) NPs with Mn2+ concentration varying between 1.5 and 5% (wt%) have been synthesized by chemical co-precipitation method at room temperature. X-ray diffraction (XRD) studies and the analysis of the selected area electron diffraction (SAED) pattern, obtained from transmission electron microscopy (TEM), confirmed the formation of zinc blende structure in all the synthesized samples. The particle sizes of the samples, as obtained from the optical absorption studies, varies between 2.2 and 2.7 nm with the increase of Mn2+ concentration between 1.5 and 5%. The room temperature photoluminescence (PL) emission measurements revealed the presence of yellow-orange emission band in all the Mn2+-doped samples which is attributed to Mn incorporation in ZnS. The Gaussian fittings of the measured PL spectra of all the samples show the presence of four PL peaks. Amongst the four PL peaks three peaks appeared at 445, 476, and 520 nm in all the samples but the fourth yellow-orange emission peak suffered a red shift from 593 to 600 nm with increasing Mn2+ concentration from 1.5 to 5%. In this report no quenching of yellow-orange emission peak is observed up to 5% Mn2+ doping concentration in ZnS. The synthesized water-soluble ZnS:Mn NPs can be further functionalized for using them as biolabels.
Chemiluminescence of Mn-Doped ZnS Nanocrystals Induced by Direct Chemical Oxidation and Ionic Liquid-Sensitized Effect as an Efficient and Green Catalyst  [PDF]
Seyed Naser Azizi,Mohammad Javad Chaichi,Parmis Shakeri,Ahmadreza Bekhradnia,Mehdi Taghavi,Mousa Ghaemy
Journal of Spectroscopy , 2013, DOI: 10.1155/2013/803592
Abstract: A novel chemiluminescence (CL) method was proposed for doping water-soluble Mn in ZnS quantum dots (QDs) as CL emitter. Water-soluble Mn-doped ZnS QDs were synthesized by using L-cysteine as stabilizer in aqueous solution. These nanoparticles were structurally and optically characterized by X-ray powder diffraction (XRD), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), UV-Vis absorption spectroscopy, and photoluminescence (PL) emission spectroscopy. The CL of ZnS QDs was induced directly by chemical oxidation and its ionic liquid-sensitized effect in aqueous solution was then investigated. It was found that oxidants, especially hydrogen peroxide, could directly oxidize ZnS QDs to produce weak CL emission in basic solutions. In the presence of 1,3-dipropylimidazolium bromide/copper, a drastic light emission enhancement was observed which is related to a strong interaction between Cu2+ and the imidazolium ring. In these conditions, an efficient CL light was produced at low pH which is suggested to be beneficial to the biological analysis. The CL properties of QDs not only will be helpful to study physical chemistry properties of semiconductor nanocrystals but also they are expected to find use in many fields such as luminescence devices, bioanalysis, and multicolor labeling probes. 1. Introduction Colloidal semiconductor nanocrystals, better known as quantum dots (QDs), are prospective materials for a wide variety of applications. QDs are characterized by a unique set of optical properties that primarily arise from quantum confinement effects [1, 2]. Luminescent properties of semiconductor nanocrystals are usually investigated by photoluminescence (PL) produced using photoexcitation [3], electrochemiluminescence (ECL) generated by electron injection [4, 5], and cathodoluminescence given from electron impact [6]. In recent years, CL and related analysis techniques have been utilized in different fields such as biology, bioimaging, biotechnology, and analytical technology because of their widespread liner range, simple instrument, and lack of background scattering light interference [7]. With development and recent advance of nanotechnology, the CL study has been extended to nanoparticle systems from traditional molecular systems. Today, the CL systems that involved nanoparticles have attracted an increased consideration because of the unique physical and chemical properties of nanoparticles [8]. Recently Zhou et al. described that ZnS QDs could enhance CL signals emitted from interaction of NaClO with H2O2 in basic medium
Synthesis and Luminescence Properties of Core/Shell ZnS:Mn/ZnO Nanoparticles  [cached]
Jiang Daixun,Cao Lixin,Liu Wei,Su Ge
Nanoscale Research Letters , 2008,
Abstract: In this paper the influence of ZnO shell thickness on the luminescence properties of Mn-doped ZnS nanoparticles is studied. Transmission electron microscopy (TEM) images showed that the average diameter of ZnS:Mn nanoparticles is around 14 nm. The formation of ZnO shells on the surface of ZnS:Mn nanoparticles was confirmed by X-ray diffraction (XRD) patterns, high-resolution TEM (HRTEM) images, and X-ray photoelectron spectroscopy (XPS) measurements. A strong increase followed by a gradual decline was observed in the room temperature photoluminescence (PL) spectra with the thickening of the ZnO shell. The photoluminescence excitation (PLE) spectra exhibited a blue shift in ZnO-coated ZnS:Mn nanoparticles compared with the uncoated ones. It is shown that the PL enhancement and the blue shift of optimum excitation wavelength are led by the ZnO-induced surface passivation and compressive stress on the ZnS:Mn cores.
Synthesis and optical properties of monodispersed Ni2+-doped ZnS nanoparticles
G. Murugadoss,M. Rajesh Kumar
Applied Nanoscience , 2013, DOI: 10.1007/s13204-012-0167-8
Abstract: Nickel-doped zinc sulfide nanoparticles were successfully synthesized in air atmosphere through chemical precipitation method using surfactants in aqueous medium. The product was characterized by different techniques such as X-ray diffraction (XRD), transmission electron microscopy (TEM), fourier transform infrared spectrometer (FT-IR), UV–visible absorption and photoluminescence (PL). Crystal structure, size and morphology of the ZnS:Ni2+ nanoparticles were investigated by XRD and TEM. In the PL emission, a couple of new peaks were observed instead of a single peak by changing the precursor solution. In addition, an enhanced PL emission was observed using surfactants. Phase changes were also observed at different temperatures.
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