Search for: sulfide
Total 253 records
, M.Sc. Thesis Sharif University of Technology ; Bagherzadeh, Reza
catalyzed oxidation of organic compounds such as olefins, sulfides, benzylics alcohols and phenolics. Cyanide-catalyzed aldimine coupling was employed to senthesize compounds with a-imineamine structural motifs : 2,3-di-(2-hydroxyphenyl)-1,2-dihydroquinoxaline, that way for synthesized NONO tetra-dentate Schiff-base ligands. With attention to solid geometry these ligands are possible to synthesize homo and hetronuclear mixed-ligand complexes. we are also synthesized homonuclear mixed-ligand Mn(III) and hetronuclear Mn(III)-Fe(III) with tetradentate Schiff-base ligand quinoxaline and acetyl acetone ligand. These complexes and ligands are characterized by FT-IR, 1H NMR, 13C NMR, UV and...
Hybrid Lead sulfide-graphene Quantum Dots: Optoelectronic Properties and Cytotoxicity Evaluation, M.Sc. Thesis Sharif University of Technology ; Simchi, Abdolreza
In recent years, quantum dots specially NIR QDs like lead sulfide have attracted a lot of attentions in various bioapplications such as bioimaging, stem cell tracking, etc. However, these materials are generally synthesized by using organic lagands like oleic acid which is not appropriate for bioapplications. Moreover, the cytotoxicity of these materials have severely restricted their applications. In this research, lead sulfide quantum dots were synthesized via a hot injection route. The nanocrystals had an average size of 3 nm passivated with oleic acid ligands and graphene nanosheets. Excitonic and photoluminescence peaks were observed in wavelengths of 950 and 1100 nm, respectively....
Leaching kinetics of stibnite in sodium hydroxide solution, Article International Journal of Engineering, Transactions B: Applications ; Volume 27, Issue 2 , February , 2014 , Pages 325-332 ; SSN: 10252495 ; Halali, M ; Hakim, M ; Bakhshandeh, M. R ; Sharif University of Technology
The leaching kinetics of stibnite in basic solution has been investigated. Spherical pellets of antimony sulphide were dissolved in 1 molar sodium hydroxide solutions at different temperatures. It was found that the shrinking core with ash layer model could satisfactorily explain the dissolution process. Using this model, it was found that initially the rate controlling step was a chemical reaction with activation energy of 10.2 kJ/mol. As the ash layer built up, diffusion through the ash layer became the rate controlling step. The activation energy for this step was found to be 33.4 kJ/mol. It was also observed that smaller particle size, larger solid to liquid ratio, and higher NaOH...
Efficient recyclable catalytic system for deoxygenation of sulfoxides: Catalysis of ionic liquid-molybdenum complexes in ionic liquid solution, Article New Journal of Chemistry ; Volume 36, Issue 4 , Dec , 2012 , Pages 971-976 ; 11440546 (ISSN) ; Ghazali Esfahani, S ; Sharif University of Technology
Three newly synthesized room temperature ionic liquids containing molybdate anion, [DMIm][MoO 2(NCS) 4], [RPy][MoO 2(NCS) 4] (R = butyl or decyl), and previously reported [BMIm][MoO 2(NCS) 4] were used as catalysts for the reduction of sulfoxides. For facilitating the recyclability of the catalysts, the ionic liquids [RMIm][PF 6] and [RPy][PF 6] (RMIm = 1-n-alkyl-3-methylimidazolium, RPy = 1-n-alkylpyridinium) were applied as ionic solvents and toluene is used as solvent for the organic phase. Molybdenum salts immobilized in RTILs constituted a reusable and efficient heterogeneous catalyst system. A maximum conversion (>99%) was achieved for reduction of diphenyl sulfoxide to diphenyl...
New mononuclear manganese(II) complexes with 2,4,6-tris(2-pyridyl)-1,3,5- triazine (tptz) - Selective catalyst in UHP oxidation of sulfides, Article Polyhedron ; Volume 34, Issue 1 , February , 2012 , Pages 202-209 ; 02775387 (ISSN) ; Hołyńska, M ; Shamkhali, A. N ; Amini, M ; Kazemi, S. H ; Zaynalpoor, S ; Mohamadi, R ; Bagherzadeh, M ; Lis, T ; Sharif University of Technology
A new manganese complex of the formula [Mn(tptz)(OH 2) 3](CF 3SO 3) 2·EtOH, (1, where tptz = (2,4,6-tris(2-pyridyl)-1,3,5-triazine) is presented, exhibiting an excellent catalytic activity and selectivity in oxidation of various sulfides to the corresponding sulfoxides with UHP (urea hydrogen peroxide) as oxidant under air at room temperature. A modified preparation procedure produces another new manganese complex of the formula [Mn(tptz)(CH 3COO)(OH 2) 2](CF 3SO 3)·3H 2O (2). X-ray structures of both Mn(II) complexes, properties (elemental analysis, electrochemistry, EPR, IR, Raman, and UV-Vis spectra), as well as DFT studies results are reported
Bacterial leaching of low-grade ZnS concentrate using indigenous mesophilic and thermophilic strains, Article Hydrometallurgy ; Volume 85, Issue 1 , 2007 , Pages 59-65 ; 0304386X (ISSN) ; Yaghmaei, S ; Vossoughi, M ; Jafari, A ; Roostaazad, R ; Turunen, I ; Sharif University of Technology
In this study low-grade sphalerite has been treated by the bioleaching process using native cultures of Acidithiobacillus ferrooxidans and Sulfobacillus thermosulfido-oxidans in order to determine the ability of these bacteria to the leaching of zinc. The effects of bacterial strain, pH, temperature, pulp density, iron precipitation, and initial concentration of ferric iron on the zinc leaching were evaluated. The bioleaching experiments were carried out in shake flasks at pH 1.5, 180 rpm, 33 °C and 60 °C for mesophilic and thermophilic bacteria, respectively. Compared with the use of laboratory reference strains or control conditions, zinc recovery from the respective concentrate was...
Influence of process variables on biooxidation of ferrous sulfate by an indigenous Acidithiobacillus ferrooxidans. Part I: Flask experiments, Article Fuel ; Volume 85, Issue 17-18 , 2006 , Pages 2555-2560 ; 00162361 (ISSN) ; Yaghmaei, S ; Salimi, F ; Jafari, A ; Sharif University of Technology
Biological oxidation of ferrous sulfate by Acidithiobacillus ferrooxidans has proved to be a significant step in the bioleaching of sulfide minerals and the treatment of acid mine drainage. The same bioreaction also has beneficial applications in the desulphurization of coal and removal of hydrogen sulfide from gaseous effluents. In this research, the effects of some process variables such as pH, temperature, elemental sulfur, amount of initial ferrous and magnesium ions on oxidation of ferrous sulfate by a native A. ferrooxidans, which was isolated from a chalcopyrite concentrate, were investigated. All experiments carried out in shake flasks at 33 °C that was obtained as optimum...
Thermal control of the size and crystalline phase of CdS nanoparticles, Article Nanotechnology ; Volume 17, Issue 15 , 2006 , Pages 3812-3816 ; 09574484 (ISSN) ; Taghavinia, N ; Marandi, M ; Sharif University of Technology
CdS nanoparticles were grown using CdSO4 and Na 2S2O3 as the precursors and thioglycerol (TG) as the capping agent. TG was shown to exhibit a catalytic role in the reaction and also acted as a capping agent. It was demonstrated that size growth is linearly related to the temperature of the reaction, i.e.the sizes can be controllably adjusted by temperature. The crystalline phase of the nanocrystals was also dependent on the temperature of growth: higher temperature favours the cubic phase. The pH also plays an important role in nanoparticle growth, as lower pH leads to a higher release rate of sulfur species. At pH as high as 10, the growth rate remains slow even at boiling temperature. This...
Some investigations on the ability of an indigenous thiobacillus ferrooxidans, used in Bio-SR process, Article CHISA 2006 - 17th International Congress of Chemical and Process Engineering, Prague, 27 August 2006 through 31 August 2006 ; 2006 ; 8086059456 (ISBN); 9788086059457 (ISBN) ; Salimi, F ; Mousavi, S. M ; Sharif University of Technology
The physicochemical techniques presently available for treatment of H2S containing gases are many and varied. In near future small gas reservoirs with high concentration of H2S will be explored, therefore the gas processing industry is seeking novel, cost effective, environmentally compatible and operator friendly technologies applicable to the small volume producrs. The continuing search for more economical methods has led to investigations into microbiological processes. The biological process which has been studied in this research is Bio-SR process. Bio-SR process uses thiobacillus ferroxidans bacteria to regenerate gas treating solution (ferrous sulfate). In this way, the effects of...
DFT calculations on the retro-ene reactions, part II: Allyl n-propyl sulfide pyrolysis in the gas phase, Article Journal of Molecular Structure: THEOCHEM ; Volume 686, Issue 1-3 , 2004 , Pages 37-42 ; 01661280 (ISSN) ; Gholami, M. R ; Haghgu, M ; Sharif University of Technology
The mechanism and kinetic aspects of the retro-ene reaction of the Allyl n-propyl sulfide and its deuterated derivative were studied using four different types of density functional theory methods with eight different levels of the basis sets. The activation energies were determined at 550.65 K. As a consequence of our calculations, a transition state is concluded that consists of a polar six-center cyclic structure. We found that the combination B3PW91/6-311++G** produces activation energy values closer to the experimental ones, but the simpler combination B3LYP/6-31G* produces excellent values too in less time. Our calculations show that the activation parameters obtained from the B3...
Preparation of Tthin Film CdS/CdTe Solar Cells: Containing CdS Nanowires and CdTe Particles, M.Sc. Thesis Sharif University of Technology ; Mohammadi, Mohammad Reza
In the present work, we have designed a novel CdS/CdTe solar cell based on CdS nanowires, as a window layer, and CdTe nanoparticles, as a absorber layer. CdS nanowires and CdTe nanoparticles were synthesized by solvothermal method. The samples were characterized by X-ray diffraction diffractometer (XRD), field emission scanning electron microscope (FE-SEM), Atomic Force Microscope (AFM) and Ultraviolet–Visible (UV–vis) spectroscopy spectrometer. Photocurrent measurements were carried out using a 150 W xenon lamp with an air-mass (AM) 1.5 filter. The performance of the solar cell based on the CdS nanowire (NW-CdS) film with 225 nm thickness and CdTe nanoparticle (NP-CdTe) film with 6 μm...
Spectrophotometric determination of sulfide based on peroxidase inhibition by detection of purpurogallin formation, Article Ecotoxicology and Environmental Safety ; Volume 91 , 2013 , Pages 117-121 ; 01476513 (ISSN) ; Kariminia, H. R ; Roosta Azad, R ; Sharif University of Technology
This paper presents a new method for spectrophotometirc detection of sulfide applying fungal peroxidase immobilized on sodium alginate. The sensing scheme was based on decrease of the absorbance of the orange compound, purpurogallin produced from pyrogallol and H2O2 as substrates, due to the inhibition of peroxidase by sulfide. Absorbance of purpurogallin was detected at 420nm by using a spectrophotometer. The proposed method could successfully detect the sulfide in the concentration range of 0.6-7.0μM with a detection limit of 0.4μM. The kinetic parameters of Michaelis-Menten with and without sulfide were also calculated. Possible inhibition mechanism of peroxidase by sulfide was deduced...
On the optimization of sphalerite bioleaching; the inspection of intermittent irrigation, type of agglomeration, feed formulation and their interactions on the bioleaching of low-grade zinc sulfide ores, Article Chemical Engineering Journal ; Volume 187 , 2012 , Pages 217-221 ; 13858947 (ISSN) ; Azad, R. R ; Arabian, D ; Molaie, A ; Nemati, F ; Sharif University of Technology
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. The effects of intermittent irrigation, type of agglomeration, feed formulation in terms of acid, enriched salt solution, initial number of microorganism, and their interactions on the bioleaching of low-grade zinc sulfide ores (containing 5.78% zinc) on growth and biooxidation efficiency of the bacteria have been evaluated. Bioleaching capacities of the isolate were optimized by the utilization the Taguchi method (e-qualitic-4) for design of experiments. As a result,...
Solution synthesis of CuSbS2 nanocrystals: a new approach to control shape and size, Article Journal of Alloys and Compounds ; Volume 736 , 2018 , Pages 190-201 ; 09258388 (ISSN) ; Sabbagh Alvani, A. A ; Mohammadpour, R ; Ge, Y ; Hannula, S. P ; Sharif University of Technology
Elsevier Ltd 2018
Chalcostibite copper antimony sulfide (CuSbS2) micro- and nanoparticles with a different shape and size have been prepared by a new approach to hot injection route. In this method, sulfur in oleylamine (OLA) is employed as a sulfonating agent providing a simple route to control the shape and size of the particles, which enables the optimization of CuSbS2 for a variety of applications. The sulfur to metallic precursor ratio appears to be one of the most effective parameters along with the temperature and time for controlling the size and morphology of the particles. The growth mechanism study shows in addition to the CuSbS2 phase the presence of not previously observed intermediate phases...
Ternary nickel cobalt iron sulfides ultrathin nanosheets grown on 3-D nickel nanocone arrays‑nickel plate current collector as a binder free electrode for fabrication of highly performance supercapacitors, Article Journal of Electroanalytical Chemistry ; Volume 810 , 2018 , Pages 78-85 ; 15726657 (ISSN) ; Shahrokhian, S ; Hosseini, H ; Sharif University of Technology
Elsevier B.V 2018
The design of 3-dimensional (3-D) nanostructured materials on the novel current collectors has recently considered as a promising strategy for developing high-performance supercapacitors. Herein, in the first step, a novel 3-D nickel nanocone arrays (NCAs) are synthesized on the surface of nickel plate (NP) by a one-step electrodeposition method without using any template (NCAs-NP). Then, a simple and efficient method is developed for fabricating ternary metal sulfides electrodes based on the electrodeposition of nickel cobalt iron sulfide (Ni-Co-Fe-S) ultrathin nanosheets on the surface of NCAs-NP. Taking advantages of the unique flower like structure of Ni-Co-Fe-S ultrathin nanosheets and...
Hydrogen bubble template fabricated nano-architecture quaternary dendritic sulfide as cathode and electro-etched carbon fiber paper as anode electrode for total novel binder-free asymmetric supercapacitors, Article Journal of Alloys and Compounds ; Volume 811 , 2019 ; 09258388 (ISSN) ; Naderi, L ; Shahrokhian, S ; Sharif University of Technology
Elsevier Ltd 2019
A novel electrode consisting of 3D porous nickel‒cobalt‒copper sulfide dendritic structures is synthesized, in which, for the first time ternary Ni–Co–Cu foam is constructed through hydrogen bubble template and followed by sulfidization via a hydrothermal reaction in thiourea. The 3D, porous Ni–Co–Cu dendritic sulfide electrode exhibits a high specific capacitance of 1203.75 F g−1 (0.963 F cm−2) at current of 1.0 mA and excellent cycling stability, excellent ratability along with high cycle stability. An asymmetric supercapacitor (ASC) using dendritic sulfide structures and reduced electro-etched carbon fiber paper (RECF) as the positive and negative electrodes, respectively is developed....
Impact of rock mineralogy on reservoir souring: A geochemical modeling study, Article Chemical Geology ; Volume 555 , November , 2020 ; Zhang, L ; Liu, L ; Shabani, A ; Sharif University of Technology
Elsevier B. V 2020
The petroleum industry suffers from reservoir souring phenomena, which has negative impacts on production facilities, health, and environment. Injection of incompatible water into the reservoir (waterflooding), which is considered as an enhanced oil recovery (EOR) method, is one of the most common causes of reservoir souring. In general, injected brine, especially seawater, contains high amounts of sulfate ion (SO42−). A high concentration of sulfate in the presence of sulfate-reducing bacteria (SRB) leads to the microbial reservoir souring. During this phenomenon, sulfide, specifically hydrogen sulfide gas (H2S) appears in the producing fluid of the reservoir. In this paper, a coupled...
Optical and structural properties of copper doped CdS thin films prepared by pulsed laser deposition, Article Scientia Iranica ; Volume 15, Issue 3 , 2008 , Pages 360-365 ; 10263098 (ISSN) ; Irajizad, A ; Azarian, A ; Tilaki, R. M ; Sharif University of Technology
Sharif University of Technology 2008
This paper presents the study of the structural and optical properties of copper doped cadmium sulfide thin films prepared by pulsed Nd:YAG laser. The copper concentration in the targets was varied from 0.05% to 5% in weight and they were heated at a temperature of 500°C in air for one hour. It was observed that annealing un-doped and doped thin films at temperatures above 160°C leads to an abrupt increase in the optical transmission, changing from dark brownish to transparent yellowish. For annealed samples at 300°C, increasing Cu concentration from 0.0% to 2%, leads to an increase in the optical transmission up to 80%, at a wavelength of about 700 nm. XRD patterns showed the hexagonal...
A novel iron complex containing an N,O-type bidentate oxazoline ligand: Synthesis, X-ray studies, DFT calculations and catalytic activity, Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Vol. 133, issue , Jun , 2014 , p. 432-438 ; Arab, A ; Derakhshandeh, P. G ; Bagherzadeh, M ; Ellern, A ; Woo, L. K ; Sharif University of Technology
A five-coordinated Fe(III) complex with the distorted trigonal bipyramidal configuration was synthesized by reactions of FeCl36H2O and 2-(2′-hydroxyphenyl)oxazoline (Hphox) as a bidentate ON donor oxazoline ligand. Complex [Fe(phox)2Cl] was fully characterized, including by single-crystal X-ray structure analysis. DFT calculations were accompanied with experimental results in order to obtain a deeper insight into the electronic structure and vibrational normal modes of complex. Oxidation of sulfides to sulfoxides in one-step was conducted by this complex as catalyst using urea hydrogen peroxide (UHP) in mixture of CH2Cl 2/CH3OH (1:1) under air at room temperature. The results show that using...
Investigating the effect of design parameters on the response time of a highly sensitive microbial hydrogen sulfide biosensor based on oxygen consumption, Article Biosensors and Bioelectronics ; Volume 70 , 2015 , Pages 106-114 ; 09565663 (ISSN) ; Yazdian, F ; Amoabediny, G ; Hakim, M ; Sharif University of Technology
Elsevier Ltd 2015
A novel hydrogen sulfide microbial biosensor was developed based on investigating the influence of four design parameters: cell concentration, immobilization bed type, hydrogen sulfide concentration, and geometrical shape of the biosensor. Thiobacillus thioparus was used as the recognition element and it was immobilized on sodium alginate as well as agarose bed. The results were optimized by the application of statistical optimization software based on response time of the system. Oxygen reduction was considered as the detection sign. Sodium alginate solution with a concentration of 2.3% (w/v) and optical density of 10 at 605. nm was found as the optimum conditions for immobilization with...