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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.
Effect of Microwave Power on the Physical Properties of Carboxylic Acid-Coated Manganese-Ion-Doped Zinc Sulfide Nanoparticles  [PDF]
Baibaswata Bhattacharjee,Chung-Hsin Lu
Journal of Nanotechnology , 2011, DOI: 10.1155/2011/916750
Abstract: Bright ZnS?:?Mn2+ nanoparticles have been synthesized employing microwave irradiation technique and using zinc 2-ethylhexanoate as a novel zinc precursor. A series of samples is obtained by changing the microwave power (from 150?W to 500?W) to study its effect on the physical properties of the ZnS?:?Mn2+ nanoparticles. The particle size increases with increasing microwave power for the samples synthesized in the microwave range of 150 W to 300 W. The decrease in particle size for higher microwave power (400?W and 500?W) can be described as an onset of the secondary nucleation due to the excess energy associated with the higher microwave power. The sample synthesized with microwave power of 300?W shows highest luminescence intensity suggesting increase in Mn2+ luminescence center for the sample synthesized at 300?W, as supported by the quantity analysis results. 1. Introduction Over the last few years, a considerable interest in the novel optical and electrical properties of doped semiconductor nanocrystals has emerged [1–5]. Semiconductor nanocrystals are interesting from a physical and chemical point of view mainly because several of their properties are very different from those of bulk materials [3]. In particular, the significant size-dependent change in the band gaps has attracted much attention. This so-called quantum-size effect allows one to tune the absorption and emission colors of nanocrystal by varying the crystal radius. Mn2+-doped materials represent a class of phosphors, which have already found their way in many applications. The 4T1 → 6A1 transition within the 3d5 configuration of the divalent manganese ion has been studied extensively, and its orange-yellow luminescence in ZnS is well documented [6]. This luminescence has also been observed in nanocrystalline ZnS?:?Mn2+ [7], and applications have already been suggested [8–10]. Different types of Mn2+ centers are present in nanocrystalline ZnS?:?Mn2+, but the orange luminescence originates exclusively from Mn2+ ions on Zn2+ sites, where the Mn2+ is tetrahedrally coordinated by S2?. ZnS doped with manganese ions (yellow-orange emission at around 590?nm) [7], copper ions (green emission at around 510?nm) [11], and silver ions (blue emission at around 440?nm) [12] have a potential application in field emission devices (FEDs) [13]. Organometallic methods for the synthesis of nanoparticles have been described by Bhargava et al. [7] and Gallagher et al. [14]. Yu et al. synthesized ZnS?:?Mn2+ nanoparticles in methanol using sodium polyphosphate as the capping agent [15]. Recently, sonochemical
A novel biological approach on extracellular synthesis and characterization of semiconductor zinc sulfide nanoparticles
Chelladurai Malarkodi,Gurusamy Annadurai
Applied Nanoscience , 2013, DOI: 10.1007/s13204-012-0138-0
Abstract: The expansion of reliable and eco-friendly process for synthesis of semiconductor nanoparticle is an important step in the emerging field of biomedical nanotechnology. In this communication, the zinc sulfide nanoparticles were biologically synthesized by using Serratia nematodiphila which was isolated from chemical company effluent. The surface plasmon resonance centered at 390 nm on the UV spectrum indicates the presence of zinc sulfide nanoparticles in the reaction mixture (S. nematodiphila and zinc sulfate); EDAX analysis also confirmed the presence of zinc sulfide nanoparticles. Scanning electron microscope image showed that the synthesized zinc sulfide nanoparticles were spherical in nature and nanoparticles of about 80 nm in size were obtained from transmission electron microscope images. The peaks in the XRD spectrum corresponding to (111), (220) and (311) show that the zinc sulfide nanoparticles are crystalline in nature. Fourier transforms infrared spectroscopy shows the functional groups of the nanoparticle in the range of 4,000–400 cm 1. Further, the antibacterial activity of zinc sulfide nanoparticles was examined against Bacillus subtilis and Klebsiella planticola. The maximum zone of inhibition occurred at 200 μl of silver nanoparticles. Due to potent antimicrobial and intrinsic properties of zinc sulfide, it is actively used for biomedical and food packaging applications.
Preparation and Antibacterial Performance of Zinc Pyrithione/Montmorillonite  [PDF]
WANG Yun-Bin, YANG Jin-Tao, FEI Zheng-Dong, CHEN Feng, ZHONG Ming-Qiang
无机材料学报 , 2010, DOI: 10.3724/sp.j.1077.2010.00512
Abstract: A novel antibacterial composite, zinc pyrithione/montmorillonite(ZPT/MMT) was in situ prepared by introducing pyrithione anion into the galleries of zinc-exchanged montmorillonite. The results of XRD, FT-IR, TG, DSC and UV-Vis DRS show that pyrithione anion exists in the form of zinc pyrithione, resulting in an increase of basal spacing of montmorillonite (d001 value) from 1.29nm to 1.85nm, and the ZPT/MMT has a favorable light and thermal stability (the decomposition temperature is above 240℃). Antibacterial assays indicate that ZPT/MMT has an excellent antibacterial activity against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus.
Formation and Photoluminescence of Zinc Sulfide Nanorods  [PDF]
S. Senthilkumaar,R. Thamiz Selvi
Journal of Applied Sciences , 2008,
Abstract: Zinc sulfide nanorods of wurtzite structure have been grown using a simple sol-gel method via ultrasonication, in the presence of a capping agent. X-ray diffraction, scanning electron microscopy, low and high resolution transmission electron microscopy and selected area electron diffraction techniques have been used to characterize the crystal structure, morphology and growth direction of the obtained nano rods. The possible mechanism of the shape evolution was investigated, which revealed that the crystal growth along the unique c axis resulted in the rod like ZnS. The photoluminescent spectrum of ZnS nanorods exhibited green emission, which may find applications in optoelectronic devices.
Antibacterial evaluation of some benzimidazole derivatives and their zinc(II) complexes
S. O. PODUNAVAC-KUZMANOVIC,D. M. CVETKOVIC
Journal of the Serbian Chemical Society , 2007,
Abstract: Zinc(II) chloride was reacted with some 1-benzylbenzimidazole derivatives (L) to give complexes of the formula ZnL2Cl2. All the ligands and their zinc(II) complexes were evaluated for their in vitro antibacterial activity against Pseudomonas aeruginosa, Bacillus cereus, Staphylococcus aureus and Sarcina lutea. Themajority of the investigated compounds displayed in vitro antimicrobial activity against very persistent microorganisms. It was found that all the tested compounds were more active against gram-positive than gram-negative bacteria. The minimum inhibitory concentration (MIC) was determined for all ligands and their complexes. The effect of the structure of the ligands and complexes on the antimicrobial activity is discussed. The complexes were found to be more toxic than the ligands.
Removal of Manganese and Iron from Groundwater in the Presence of Hydrogen Sulfide and Ammonia  [PDF]
Milka M. Vidovi?, Ivana S. Trajkovi?, Sa?a S. Rogan, Vladimir M. Petrovi?, Sanja Z. Jovani?
Journal of Water Resource and Protection (JWARP) , 2014, DOI: 10.4236/jwarp.2014.619159
Abstract: Presence of iron and manganese in water not only affects the organoleptic properties of water, but also can cause a number of problems in drinking water treatments. Their removal in drinking water preparation processes becomes more complicated in the presence of hydrogen sulfide and ammonia in water. There are certain commercialized products at the market that are used for removal of manganese, iron and ammonia, but it is of crucial importance to establish an appropriate order of removal in the technological process during drinking water treatment. Through the various combinations of commercialized filtration media, the removal of iron, manganese, hydrogen sulfide and ammonia, was being examined and on the basis of obtained results their effectiveness was estimated. Research results have shown that hydrogen sulfide is pollutant that causes problems during the adsorption in removing manganes. Ammonia, which is bonded to hydrogen sulphide influences the volume of treated water when it comes to removing the iron and manganese. Decrease in the concentration of hydrogen sulfide at the entrance to Filtersorb FMH for four times, has led to an increase in the volume of treated water in the amount of two times, followed by the breakthrough point of concentration of manganese. For complete usage capacity of commercialized products for the removal of these pollutants, finding their mutual bond in compounds which are present in the water, is of the importance.
Zinc Sulfide Tubes Reinforced with Carbon Nanofibers  [PDF]
N. N. Kolesnikov,D. N. Borisenko,E. B. Borisenko,A. V. Timonina,V. V. Kveder
Journal of Nanomaterials , 2009, DOI: 10.1155/2009/126354
Abstract: Zinc sulfide submicron and nanotubes with outer diameters in the range from 100 to 1000 nm were produced through chemical deposition from vapor under argon pressure. The novel process provides formation of ZnS tubes reinforced with carbon nanofibers. This is the first time that the ZnS tubes are grown with fibers during deposition.
Dc conductivity of consolidated nanoparticles of zinc sulfide
Sutheertha S Nair and M Abdul Khadar
Science and Technology of Advanced Materials , 2008,
Abstract: Zinc sulfide nanoparticles with average grain sizes ranging from 3 to 12 nm were prepared by arrested chemical preparation, followed by suitable thermal processing. The size of the grains was determined by x-ray line broadening. Dc measurement was performed on compacts of nanoparticles using a Keithley electrometer in the temperature range of 313–423 K. The dc conductivity, σdc, of our samples is much higher than that of ZnS single crystals; σdc increases with a decrease in the grain size.
On the origin of life in the Zinc world. 2. Validation of the hypothesis on the photosynthesizing zinc sulfide edifices as cradles of life on Earth
Armen Y Mulkidjanian, Michael Y Galperin
Biology Direct , 2009, DOI: 10.1186/1745-6150-4-27
Abstract: If life started within photosynthesizing ZnS compartments, it should have been able to evolve under the conditions of elevated levels of Zn2+ ions, byproducts of the ZnS-mediated photosynthesis. Therefore, the Zn world hypothesis leads to a set of testable predictions regarding the specific roles of Zn2+ ions in modern organisms, particularly in RNA and protein structures related to the procession of RNA and the "evolutionarily old" cellular functions. We checked these predictions using publicly available data and obtained evidence suggesting that the development of the primeval life forms up to the stage of the Last Universal Common Ancestor proceeded in zinc-rich settings. Testing of the hypothesis has revealed the possible supportive role of manganese sulfide in the primeval photosynthesis. In addition, we demonstrate the explanatory power of the Zn world concept by elucidating several points that so far remained without acceptable rationalization. In particular, this concept implies a new scenario for the separation of Bacteria and Archaea and the origin of Eukarya.The ability of the Zn world hypothesis to generate non-trivial veritable predictions and explain previously obscure items gives credence to its key postulate that the development of the first life forms started within zinc-rich formations of hydrothermal origin and was driven by solar UV irradiation. This concept implies that the geochemical conditions conducive to the origin of life may have persisted only as long as the atmospheric CO2 pressure remained above ca. 10 bar. This work envisions the first Earth biotopes as photosynthesizing and habitable areas of porous ZnS and MnS precipitates around primeval hot springs. Further work will be needed to provide details on the life within these communities and to elucidate the primordial (bio)chemical reactions.This article was reviewed by Arcady Mushegian, Eugene Koonin, and Patrick Forterre. For the full reviews, please go to the Reviewers' reports sect
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