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Solvothermal synthesis of CuMS2 (M=A1, In, Fe) nanoparticles and effect of coordinating solvent on the crystalline structure
,
Article
Scientia Iranica
;
Volume 21, Issue 6
,
2014
,
Pages 2468-2478
;
ISSN: 10263098
; Ghasemzadeh, R
; Zad, A. I
; Mirkazemi, S. M
; Masoud, A
;
Sharif University of Technology
Abstract
CuMS2 (M=A1, In, Fe) ternary compounds were synthesized via the facile polyol method in autoclave. Depending on the functional groups of solvent and surfactant, the structure of the nanocrystals can be controlled in the form of wurtzite or chalcopyrite. The chalcopyrite structure was obtained when the precursors solved in the mixture of diethylene glycol, polyethylene glycol 600 and ammonium hydroxide. When the solvent was replaced by ethylene diamine, the wurtzite was obtained along with chalcopyrite (polytypism). The products were characterized by X-Ray Diffraction (XRD) for analysis of structural properties, Transmission Electron Microscopy (TEM) for studying morphological...
CdS nanoparticle sensitized titanium dioxide decorated graphene for enhancing visible light induced photoanode
, Article Applied Surface Science ; Vol. 320, issue , 30 November , 2014 , pp. 772-779 ; ISSN: 01694332 ; Faraji, M ; Nien, Y. T ; Moshfegh, A. Z ; Sharif University of Technology
Abstract
CdS/TiO2/graphene (CTG) nanocomposite thin films were synthesized by a facile production route. The TiO2/graphene (TG) nanocomposite was initially fabricated by sol-gel method in such a way that TiO2 nanoparticles loaded on graphene oxide (GO) sheet via photocatalytic process. Then, CdS nanoparticles were deposited on the TG thin film by successive ion layer adsorption and reaction process (SILAR) approach. Based on atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses, the TG thin film possessed a larger surface area as compared with the pure TiO2 thin film due to presence of graphene sheet. UV/visible spectroscopy exhibited...
A water-oxidizing dinuclear iron complex as an efficient catalyst toward organic sulfide oxidation
, Article Journal of Coordination Chemistry ; Vol. 67, issue. 18 , Jul , 2014 , p. 3026-3032 ; Najafpour, M. M ; Zare, M ; Holynska, M ; Moghaddam, A. N ; Bagherzadeh, M ; Sharif University of Technology
Abstract
In this paper, we report that a known dinuclear Fe complex, [tpa(H2O)FeOFe(H2O)tpa](ClO4)4 (tpa: tris(2-pyridylmethyl)amine), is an efficient catalyst toward organic sulfide oxidation in the presence of urea-hydrogen peroxide
Corrosion investigation of pipeline steel in hydrogen sulfide containing solutions
, Article Journal of Applied Sciences ; Volume 12, Issue 23 , 2012 , Pages 2454-2458 ; 18125654 (ISSN) ; Taheri, H ; Ismail, M. C ; Dolati, A ; Sharif University of Technology
Abstract
The hydrogen-induced cracking (HIC) behavior of X70 pipeline steel was studied by means of Linear Polarization Resistance (LPR), hydrogen permeation tests, weight loss and Scanning Electron Microscopy (SEM). In this study, the dissolved HZS was created by chemical reactions in solution. The specimens were immersed into synthetic sea water saturated with HZS. The experimental results showed that the increase of exposure time and HZS concentration leads to an increase of the hydrogen content in X70 steel, which plays a key role in the initiation and propagation of HIC
Near-white emitting QD-LED based on hydrophilic CdS nanocrystals
, Article Journal of Luminescence ; Volume 132, Issue 2 , 2012 , Pages 467-473 ; 00222313 (ISSN) ; Marandi, M ; Saievar Iranizad, E ; Taghavinia, N ; Liu, B ; Sun, H. D ; Sun, X. W ; Sharif University of Technology
Abstract
In this work we report fabrication of a nanocrystal (NC)-based hybrid organicinorganic LED with structure of ITO/PEDOT:PSS/PVK/CdS-NCs/(Al or Mg:Ag). The hydrophilic CdS NCs were synthesized using a novel aqueous thermochemical method at 80 °C and sizes (around 2 nm) were controlled by thioglycolic acid (TGA) as the capping agent. The favorite feature of these NCs is their relatively high emission intensity and broad, near-white emission. The hydrophilic CdS NCs were successfully spin coated using Triton X-100 as the wetting agent. The fabricated LEDs demonstrated a turn on voltage about 7 V for Al metallic contact. The electroluminescence was a broad spectrum at 540 and 170 nm width, which...
Enhanced photoelectrochemical activity of Ce doped ZnO nanocomposite thin films under visible light
, Article Journal of Electroanalytical Chemistry ; Volume 661, Issue 1 , 2011 , Pages 106-112 ; 15726657 (ISSN) ; Amiri, M ; Azimirad, R ; Moshfegh, A. Z ; Sharif University of Technology
Abstract
Ce-doped ZnO and pure ZnO nanocomposite thin films with different Ce/Zn ratios (0, 2, 5, 10, 15, 20, and 30 at.%) have been prepared by sol-gel method at optimum annealing temperature of 500 °C. The synthesized samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis spectrophotometry. According to our XPS data analysis, there are three major metal ions namely Ce3+, Ce4+ and Zn 2+ that coexist on the surface. The XRD measurements indicate that the ZnO thin films have a hexagonal wurtzite structure, and CeO2 crystallites formed in the Ce-doped ZnO nanocomposite thin films. Photoelectrochemical property of the samples was studied by three...
AC impedance and cyclic voltammetry studies on PbS semiconducting film prepared by electrodeposition
, Article Journal of Electroanalytical Chemistry ; Volume 661, Issue 1 , 2011 , Pages 265-269 ; 15726657 (ISSN) ; Jafarian, M ; Danaee, I ; Gobal, F ; Mahjani, M. G ; Sharif University of Technology
Abstract
Semiconducting lead sulfide film was deposited on Stainless Steel (SS) electrode by cyclic voltammetry (CV) at room temperature. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry were used to investigate the electrochemical properties of PbS film in Na2SO4 solution. The voltammetric results showed that oxidative dissolution of PbS film occurred at about 0.21 V vs. Ag/AgCl and total film detachment from the surface occurs with increasing potential. It is concluded that the electrode surface was not passivated by sulfur produced from oxidative dissolution of PbS film. Also, cathodic reduction of the film continued to beyond the hydrogen evolution at -1.35 V vs. Ag/AgCl....
One-dimensional cadmium sulfide (CdS) nanostructures by the solvothermal process: Controlling crystal structure and morphology aided by different solvents
, Article Materials Letters ; Volume 65, Issue 9 , 2011 , Pages 1291-1294 ; 0167577X (ISSN) ; Mohammadi, M. R ; Fray, D. J ; Sharif University of Technology
Abstract
Cadmium sulfide (CdS) nanowires and nanorods with different aspect ratios were successfully synthesized by the solvothermal method aided with various solvents, namely ethylenediamine, ethanolamine and triethylene tetraamine. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analyses revealed that, highly pure CdS nanostructures were crystallized with different structures and preferable growth orientations depending on solvent nature. Field emission electron microscope (FE-SEM) images showed that the aspect ratio of CdS nanostructures depends upon the dielectric constant and boiling temperature of solvents. CdS nanostructures with the highest aspect ratio in the form...
Optimum operating conditions for direct oxidation of H2S in a fluidized bed reactor
, Article World Academy of Science, Engineering and Technology ; Volume 77 , 2011 , Pages 411-415 ; 2010376X (ISSN) ; Kazemeini, M ; Fattahi, M ; Amjadia, A ; Sharif University of Technology
Abstract
In this research a mathematical model for direct oxidization of hydrogen sulfide into elemental sulfur in a fluidized bed reactor with external circulation was developed. As the catalyst is deactivated in the fluidized bed, it might be placed in a reduction tank in order to remove sulfur through heating above its dew point. The reactor model demonstrated via MATLAB software. It was shown that variations of H 2S conversion as well as; products formed were reasonable in comparison with corresponding results of a fixed bed reactor. Through analyzing results of this model, it became possible to propose the main optimized operating conditions for the process considered. These conditions included;...
Removal of hydrogen sulfide from methane using commercial polyphenylene oxide and Cardo-type polyimide hollow fiber membranes
, Article Korean Journal of Chemical Engineering ; Volume 28, Issue 3 , March , 2011 , Pages 902-913 ; 02561115 (ISSN) ; Savoji, H ; Soltanieh, M ; Matsuura, T ; Tabe, S ; Sharif University of Technology
Abstract
The performance of commercially available poly (2,6-dimethyl-1,4-phenylene oxide) (PPO) and Cardotype polyimide (PI) hollow fiber membranes was investigated in removing hydrogen sulfide from methane in a series of bench-scale experiments. It was observed that in the concentration range of hydrogen sulfide in methane from 101 to 401 ppm, the methane permeability decreased in the presence of hydrogen sulfide for Cardo-type polyimide hollow fiber membranes, whereas the PPO membrane performance was not affected. The separation coefficients of hydrogen sulfide/methane were 6 and 4 for PI and PPO membranes, respectively. Effects of temperature on the performance of PI and PPO membranes were...
Leaching of a zinc ore and concentrate using the Geocoat™ technology
, Article Minerals Engineering ; Volume 24, Issue 1 , 2011 , Pages 64-69 ; 08926875 (ISSN) ; Petersen, J ; Roostaazad, R ; Hosseini, S ; Mohammad Mousavi, S ; Najafi, A ; Vasiri, A. K ; Sharif University of Technology
Abstract
In this study, the Geocoat™ technology was used for the extraction of zinc from a mineral concentrate obtained from the Kooshk mine (Yazd, Iran) by a culture dominated by the mesophilic bacterium Acidithiobacillus ferrooxidans in a packed column bioreactor. A low grade sphalerite ore was used as support for the concentrate coating. During the 100 days of leaching pH, Fe3+, Fetotal, microbial population density and zinc extraction were measured. The final zinc extraction from concentrate and low grade support was 97% and 78%, respectively, and it was found that leaching from the support does not proceed significantly before leaching from the coating is completed
Polymeric ionic liquid nanogel-anchored tungstate anions: A robust catalytic system for oxidation of sulfides to sulfoxides
, Article New Journal of Chemistry ; Volume 39, Issue 2 , 2015 , Pages 1348-1354 ; 11440546 (ISSN) ; Nazari Chamazkoti, M ; Hosseini, S. H ; Sharif University of Technology
Abstract
A new heterogeneous catalytic system was prepared by immobilization of tungstate ions on a cross-linked poly(ionic liquid) nanogel. The solid nanogel was easily synthesized by a surfactant-less method. The resulting catalyst was highly active in selective oxidation of sulfides to sulfoxides by H2O2. The oxidation reactions were successfully performed under solvent-free conditions affording high yields. The catalyst was recycled and reused for several reaction cycles without any significant loss of catalytic activity
Plasticization effect on performance of polyphenylene oxide hollow fiber membrane at high concentrations of hydrogen sulfide
, Article 19th International Congress of Chemical and Process Engineering, CHISA 2010 and 7th European Congress of Chemical Engineering, ECCE-7, 28 August 2010 through 1 September 2010 ; 2010 ; Niknejad, S. M. S ; Soltanieh, M ; Sharif University of Technology
Abstract
Natural gas contains several impurities, e.g., CO 2 and H 2S, which have undesirable effects on the performance of the glassy polymeric membranes. The plasticization effect of H 2S at high concentrations on the gas separation performance of polyphenylene oxide hollow fiber membrane has been studied at different compositions of H 2S and feed pressures. The existence of high concentrations of H 2S in CH 4 feed mixture, which is present in many natural gas sources in Iran, enhances plasticization. For a H 2S/CH 4 mixture containing 5008 ppm H 2S at ≈ 75 psig, the H 2S permeance reduces by > 45% from its initial value. H 2S acts as a plasticizer in H 2S/CH 4 membrane separation at elevated...
TiO2 nanotubular fibers sensitized with CdS nanoparticles
, Article EPJ Applied Physics ; Volume 50, Issue 2 , 2010 ; 12860042 (ISSN) ; Taghavinia, N ; Aghabozorg, H. R ; Iraji Zad, A ; Sharif University of Technology
Abstract
In this study TiO2 nanotubular fibers were prepared and subsequently loaded with CdS nanoparticles to obtain visible light activate nanofibers with modified structure. Preparation of TiO2 fibers was based on templating method and Liquid phase deposition technique (LPD) with cellulose fibers as templates. Using LPD, thickness of the TiO2 layer could be controlled precisely by adjusting the reaction conditions, therefore after removal of the template, the resulting material has a fibrous structure, mimicking the cellulose fibers shape. CdS nanoparticles were synthesized by thermochemical growth method and attached to TiO2 fibers through impregnation method. The pure composite nanofibers were...
Controlled nucleation and growth of CdS nanoparticles by turbulent dispersion
, Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 81, Issue 2 , 2010 ; 15393755 (ISSN) ; Javidpour, L ; Taghavinia, N ; Rahimi Tabar, M. R ; Sahimi, M ; Bagheri Tar, F ; Sharif University of Technology
Abstract
We propose and test a method for controlling the size of nanoparticles, which plays a fundamental role in their electrical, optical, and mechanical properties. The method utilizes turbulent mixing, and is applicable to the fabrication of any type of nanoparticle that uses a solution environment in the preparation process. We show by well-controlled experiments on the CdS nanoparticles, which are semiconducting materials, that the average size □d□ of the particles decreases with Reynolds number Re
Catalytic behavior of an iron(III) complex containing an N,O-type bidentate oxazoline ligand for selective oxidation of sulfides
, Article Transition Metal Chemistry ; Volume 41, Issue 1 , 2016 , Pages 97-105 ; 03404285 (ISSN) ; Khaksar, M ; Arab, A ; Masoomi Jahandizi, R ; Bagherzadeh, M ; Boghaei, D. M ; Ellern, A ; Keith Woo, L ; Sharif University of Technology
Springer International Publishing
Abstract
The reaction of Fe(acac)3 and 2-(2′-hydroxyphenyl)oxazoline (Hphox) as a bidentate O,N donor ligand afforded a six-coordinated iron(III) complex [Fe(phox)2(acac)] with distorted octahedral configuration. The complex was isolated as an air-stable crystalline solid and characterized by elemental analysis, FTIR, solution electrical conductivity, and by single-crystal X-ray structure analysis. The structure, electronic properties, and vibrational normal modes of the complex were investigated by DFT. The use of this complex as a catalyst for the oxidation of sulfides to their corresponding sulfoxides using urea hydrogen peroxide as the primary oxidant was investigated. The catalyst shows very...
Kinetics of oxygen adsorption on ZnS nanoparticles synthesized by precipitation process
, Article Materials Science- Poland ; Volume 34, Issue 2 , 2016 , Pages 260-265 ; 20831331 (ISSN) ; Sadrnezhad, S. K ; Namivandi Zangeneh, R ; Oghabian, M. A ; Sharif University of Technology
Walter de Gruyter GmbH
Abstract
ZnS nanoparticles were synthesized through a one-step precipitation process. Effect of time and temperature on the formation reaction was investigated. The synthesized samples were characterized by X-ray diffraction (XRD), ultraviolet (UV) visible absorption and photoluminescence (PL) spectrophotometry. Based on XRD and UV-Vis data, the particles produced at 70 °C had a mean particle size of about 5 nm. Increasing time and temperature of the synthesis reaction resulted in photoluminescence intensification. PL spectroscopy helped understanding the adsorption kinetics of oxygen on ZnS nanoparticles during the precipitation synthesis process. Fabrication of ZnS structures with appropriate...
A general two-step chemical vapor deposition procedure to synthesis highly crystalline transition metal dichalcogenides: a case study of MoS2
, Article Materials Research Bulletin ; Volume 76 , 2016 , Pages 473-478 ; 00255408 (ISSN) ; Vosoughi, M ; Maghsoudi, H ; Simchi, A ; Sharif University of Technology
Abstract
A green and simple synthesis method based on a two-step chemical vapor deposition approach has been developed to synthesize transition metal dichalcogenides flakes. With non-toxic precursor such as transition metal oxides and elemental sulfur, large-area, strong photoluminescent and uniform MoS2 nanoflakes were produced at a relatively low growth temperature (650 °C). Controlling the layer number and morphology was achieved only by precursor concentration without any oxide impurity revealed by SEM, PL and Raman spectroscopy. This method can be used to make wide range of metal chalcogenides such as ZnS, SnS2, PtS2 and PdS2
Enhancing bioleaching and iron oxidation efficiency of native strain of acidithiobacillus ferrooxidans, by optimizing the ambient growth conditions
, Article Pollution Research ; Volume 28, Issue 3 , 2009 , Pages 329-336 ; 02578050 (ISSN) ; Nemati, F ; Roostaazad, R ; Shitole, M. G ; Gade, W. N ; Sharif University of Technology
Abstract
In this study, we have investigated the bioleaching potential of a native strain of Acidithiobacillus ferrooxidans isolated from zinc and lead sulfide mines under varied ambient conditions of growth and substrate consumption. In the process of standardizing growth conditions to improve iron oxidation, bioleaching of zinc and lead is also found to be enhanced. The effects of pH, temperature, initial inoculum, Fe2+ and ammonium sulphate concentration on growth and bio-oxidation efficiency of the bacteria have been evaluated. The results indicate that the optimum pH required for the growth of the bacterium is 1.8; however, the same for maximum efficiency is 1.5. It is also found that pH has a...
Improved performance of low cost CuInS2 superstrate-type solar cells using Zinc assisted spray pyrolysis processing
, Article Journal of Physics D: Applied Physics ; Volume 50, Issue 48 , 2017 ; 00223727 (ISSN) ; Mahjoub, A. R ; Taghavinia, N ; Sharif University of Technology
Abstract
Superstrate configuration CuInS2 (CIS) solar cells are fabricated using a spray pyrolysis method. We avoided selenization process, cyanide etching and CdS buffer layer, to keep the process 'green'. CIS layers are formed by spray pyrolysis of an aqueous precursor ink containing metal chloride salts and thiourea at 350 °C. We investigated the effect of intentional Zn doping on structural, morphological and photovoltaic response of the fabricated CIS films by dissolving ZnCl2 in aqueous precursor solution. At a zinc doping level ranging between 0.25 and 1.00 mol%, Zn doping is found to improve the CIS crystal growth and surface morphology of CIS films. Compared with the performance of the...