Search for: sulfide
Total 251 records
A new colloidal technique for the synthesis of lead sulfide nanoparticles, Article Scientia Iranica ; Volume 10, Issue 3 , 2003 , Pages 357-360 ; 10263098 (ISSN) ; Ghamsari, M. S ; Sharif University of Technology
Sharif University of Technology 2003
In this paper, the use of colloid chemistry in the synthesis of 5 A° lead sulfide semiconductor nanoparticles has been described. Here, hydrogen sulfide gas dissolved in water is used for the chemical reaction, instead of purging the H2S gas into the solution, which has an influence on particle size. In this technique, the growth of particles was controlled by the addition of EDTA. A fast evolution of the optical absorption spectrum demonstrated the following synthesis. Soon after synthesis reaction, the sample exhibits a structural absorption spectrum with one well-defined peak in a 240 nm wavelength. The absorption spectrum shows a featureless structure, with no tail near the absorption...
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
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
Selective oxidation of organosulfurs with a sandwich-type polyoxometalate/hydrogen peroxide system, Article Polyhedron ; Volume 186 , 1 August , 2020 ; Amini, M ; Dastyar, M. A ; Bayrami, A ; Bagherzadeh, M ; Farnia, S. M. F ; Janczak, J ; Sharif University of Technology
Elsevier Ltd 2020
A dimeric tungstophosphate, Na14[Co4(PW9O35)2].28H2O (1), was synthesized via a simple one-pot method and characterized by single-crystal X-ray crystallography. Nanocluster 1 was exhibited to be able to selective oxidation of aliphatic and aromatic sulfides to sulfoxides in the presence of hydrogen peroxide at room temperature with high performance. Further investigations showed that this catalyst could reuse four times without a significant reduction in its activity for the oxidation of methyl phenyl sulfide. © 2020 Elsevier Ltd
Tris[(2-oxazolinyl)phenolato]manganese(III) as catalyst for mild and efficient oxidation of sulfides to sulfones with Oxone®, Article Journal of Chemical Research - Part S ; Issue 12 , 2003 , Pages 765-767 ; 03082342 (ISSN) ; Sharif University of Technology
Scientific Reviews Ltd 2003
Tris[(2-oxazolinyl)phenolato]manganese(III), Mn(phox)3, catalysed oxidation of dialkyl, diaryl, dibenzyl, and alkyl aryl sulfides to the corresponding sulfones is carried out by Oxone® in biphasic conditions (CH2Cl2/H2O), in the presence of tetra n-butylammonium bromide as phase transfer agent at room temperature in very short reaction times (5 min.) with quantitative yields
Bioleaching of low-grade sphalerite using a column reactor, Article Hydrometallurgy ; Volume 82, Issue 1-2 , 2006 , Pages 75-82 ; 0304386X (ISSN) ; Jafari, A ; Yaghmaei, S ; Vossoughi, M ; Roostaazad, R ; Sharif University of Technology
The effects of several variables on zinc recovery in column bioleaching have been investigated. The ore contained sphalerite and pyrite as the main sulfide minerals and chalcopyrite and galena as minor minerals. Tests were carried out using a bench-scale column leach reactor which was inoculated with mesophilic (Acidithiobacillus ferrooxidans) and thermophilic (Sulfobacillus) iron oxidizing bacteria; initially isolated from the Sarcheshmeh chalcopyrite concentrate (Kerman, Iran) and Kooshk sphalerite concentrate (Yazd, Iran), respectively. In the inoculated column, jarosite and elemental sulfur were formed. The leaching rate of sphalerite tended to increase with dissolved ferric ion...
Synthesis and Catalytic Properties of Novel Manganese (III)-oxazine Complex in Oxidation of Sulfides and Alcohols, M.Sc. Thesis Sharif University of Technology ; Bagherzadeh, Mojtaba
In this study new manganese(III) complexes of phox [Mn(phox)2(MeOH)2](ClO4), (phox= 2-(2` hydroxyphenyl)-5,6-dihydro-1,3-oxazine) have been synthesized and characterized with CHN,NMR and IR.The six-membered bidentate (N,O) oxazine ligand have been widely used throughout organometallic and inorganic chemistry, and are particularly important in homogeneous catalysis. The presence of N and O donor sites in oxazines may modify signiﬁcantly the ligand roles for the variation of steric and electronic properties. Therefore, such systems are worth exploring for new catalytic uses . Catalytic oxidation reactions provide excellent alternatives for the use of stoichiometric reagents like urea...
Synthesis of NO-bidentate- and ONO-Tridentate-Oxovanadium(IV) Complexes Supported on Fe¬3O4@SiO2 Core-Shell Magnetic Nanoparticle and Their Application in Oxidation of Sulfides and Alkenes
Sharif University of Technology
To synthesizeFe3O4@SiO2 core-shellnanoparticles,at first,Fe3O4 magnetic nanoparticle synthesisedby usingcoprecipitation method.Then tetraethyl orthosilicate (TEOS) was used to coverthe surface of this nanoparticle with layer of silica. In the next step, the surface of Fe3O4@SiO2 core-shellnanoparticlesfunctionalized by NO-bidentate and ONO-tridentate ligands. Finally the functionalized nanoparticle coordinated to oxovanadium(IV) to achieve Fe3O4@SiO2@NO-VO2+ and Fe3O4@SiO2@ONO-VO2+nanocatalysts for selective oxidation of sulfides to corresponding sulfoxide and oxidation of alkene. FT-IR, 1HNMR, 13CNMR, SEM, VSM and ICP analysis were used for characterization of this nanocatalysts. This...
Synthesis, X-ray studies, and catalytic activity of tridentate Schiff base dioxo-molybdenum(VI), Article Journal of Coordination Chemistry ; Volume 67, Issue 14 , 2014 ; ISSN: 00958972 ; Khaksar, M ; Boghaei, D. M ; Bagherzadeh, M ; Ellern, A ; Woo, L. K ; Sharif University of Technology
The reaction of a solution of MoO2(acac)2 in CH3OH and salicylidene 2-picoloyl hydrazone as a tridentate ONO donor Schiff base (ONO) afford a six-coordinated Mo(VI) complex [MoO2(ONO)(CH3OH)], with a distorted octahedral configuration. [MoO2(ONO)(CH3OH)] was isolated as an air-stable crystalline solid and fully characterized by single-crystal X-ray structure analysis. [MoO2(ONO)(CH3OH)] shows reactivity in the oxidation of sulfides to their corresponding sulfoxides using urea hydrogen peroxide as the oxidant at room temperature under air
Synthesis, X-ray studies, DFT calculations and catalytic activity of a novel iron complex containing an N, O-type bidentate oxazine ligand, Article Polyhedron ; Volume 61 , 2013 , Pages 94-98 ; 02775387 (ISSN) ; Haghdoost, M. M ; Bagherzadeh, M ; Ellern, A ; Woo, L. K ; Sharif University of Technology
The reactions of FeCl3·3H2O and 2-(2′-hydroxyphenyl)-5,6-dihydro-1,3-oxazine (N-O) as a bidentate O, N donor ligand afforded a five-coordinated iron(III) complex, [Fe(N-O) 2Cl], with a distorted trigonal bipyramidal configuration. The complex [Fe(N-O)2Cl] was isolated as an air-stable crystalline solid and was fully characterized, including by single-crystal X-ray structure analysis. The complex [Fe(N-O)2Cl] shows very efficient reactivity in the oxidation of sulfides to their corresponding sulfoxides using urea hydrogen peroxide (UHP) as the oxidant at room temperature under air. To get an insight into the electronic structure of the complex, the experimental studies have been accompanied...
Catalytic efficacy of an oxido-peroxido tungsten(VI) complex: Synthesis, X-ray structure and oxidation of sulfides and olefins, Article Journal of Coordination Chemistry ; Volume 66, Issue 11 , Jan , 2013 , Pages 1897-1905 ; 00958972 (ISSN) ; Bagherzadeh, M ; Eftekhari Sis, B ; Ellern, A ; Woo, L. K ; Sharif University of Technology
An oxido-peroxido tungsten(VI) complex [WO(O2)L(CH 30H)] using salicylidene benzoyl hydrazine as a tridentate ONO donor Schiff base (H2L) has been synthesized and characterized by elemental analysis, IR, 1H NMR, molar conductance data, and single-crystal X-ray analysis. The complex was used as a catalyst for epoxidation of olefins and oxidation of sulfides. The results show that epoxides and sulfoxides were produced in high yield, turnover number, and selectivity
Selective oxidation of sulfides and olefins by a manganese (III) complex containing an N,O-type bidentate oxazine ligand, Article Journal of Coordination Chemistry ; Volume 66, Issue 3 , 2013 , Pages 464-472 ; 00958972 (ISSN) ; Bagherzadeh, M ; Moradi-Shoeili, Z ; Boghaei, D. M ; Ellern, A ; Woo, L. K ; Sharif University of Technology
A new manganese(III) complex [(N-O)2Mn(OAc)] was synthesized using 2-(2'-hydroxyphenyl)-5,6-dihydro-1,3-oxazine (N-O) as a bidentate O, N donor. The complex has been characterized by elemental analysis, IR, UV-vis spectroscopy, and X-ray structure analysis. Oxidation of sulfides and epoxidation of olefins, respectively, to their corresponding sulfoxides and epoxides were conducted by this catalyst using urea hydrogen peroxide as oxidant at room temperature under air. The catalyst is efficient in oxidation reactions giving high yields and selectivities
Natural gas sweetening using ionic liquids, experiment and modeling, Article CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Conference PRES, 25 August 2012 through 29 August 2012 ; August , 2012 ; Ghotbi, C ; Jalili, A. H ; Taghikhani, V ; Sharif University of Technology
A discussion covers the general descriptions and basic properties of ionic liquids (IL); main application areas, e.g., solvent replacement, purification of gases, homogenous and heterogeneous catalysis, biological reactions media, and removal of metal ions; and results of the research and works relating to gas solubility measurement and thermodynamic modeling of gas solubility with focus on acid gas solubility in IL. This is an abstract of a paper presented at the CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction (Prague, Czech Republic...
Synthesis, X-ray structure and oxidation catalysis of a oxido-peroxido molybdenum(VI) complex with a tridentate Schiff base ligand, Article Inorganic Chemistry Communications ; Volume 20 , 2012 , Pages 86-89 ; 13877003 (ISSN) ; Amini, M ; Parastar, H ; Jalali Heravi, M ; Ellern, A ; Woo, L. K ; Sharif University of Technology
A new oxido-peroxido molybdenum(VI) complex [MoO(O 2)L(CH 3OH)] was synthesized, using salicylidene benzoyl hydrazine as tridentate ONO donor Schiff base ligand (H 2L). The complex has been characterized by elemental analysis, IR, 1H NMR, molar conductance data, and finally by X-ray structure analysis. This complex functions as facile olefin epoxidation catalyst with hydrogen peroxide (H 2O 2) as terminal oxidant and sodium hydrogen carbonate (NaHCO 3) as a co-catalyst at room temperature. Catalytic potentiality of complex is also exhibited in oxidation of sulfides. The catalyst show very much efficient reactivity in the oxidation reactions giving high yield, turnover number (TON) and...
Nanoparticle supported, magnetically separable vanadium complex as catalyst for selective oxidation of sulfides, Article Journal of Coordination Chemistry ; Volume 65, Issue 4 , 2012 , Pages 591-601 ; 00958972 (ISSN) ; Haghdoost, M. M ; Shahbazirad, A ; Sharif University of Technology
A magnetically recyclable vanadium(V) catalyst was synthesized by covalent anchoring of VO(salen)Cl on silica-coated Fe 3O 4 nanoparticles. This straightforward preparation yields magnetically separable Fe 3O 4@SiO 2@VO(salen) nanoparticles with high vanadium loading. These nanoparticles were efficient catalysts for selective oxidation of sulfides to corresponding sulfoxides with urea hydrogen peroxide in excellent yields. Leaching and recycling experiments revealed that the nanocatalyst can be applied for nearly complete oxidation of sulfides for at least five successive cycles
Determination of optimal conditions for pressure oxidative leaching of sarcheshmeh molybdenite concentrate using Taguchi method, Article Journal of Mining and Metallurgy, Section B: Metallurgy ; Volume 48, Issue 1 , 2012 , Pages 89-99 ; 14505339 (ISSN) ; Yoozbashizadeh, H ; Sharif University of Technology
The present research work is based on finding the optimum conditions for pressure oxidative leaching of the molybdenite concentrate to produce technical-grade molybdic oxide (MoO 3) with high recovery through further treatment of the filtrate solution. The Taguchi method was used to design and minimize the number of experiments. By using Taguchi orthogonal (L 25) array, five parameters (time, temperature, oxygen pressure, pulp density and acid concentration) at five levels were selected for 25 experiments. The experiments were designed and carried out in a high-pressure reactor in the presence of nitric acid as solvent and oxidizing agent for the molybdenite concentrate and its ReS 2...
Aging effect of quantum dots on solar cells sensitized with nano-crystals of CdS and PbS, Article Iranian Journal of Physics Research ; Volume 14, Issue 4 , 2015 , Pages 351-360 ; 16826957 (ISSN) ; Irjizad, A ; Samadpoor, M ; Sharif University of Technology
Isfahan University of Technology 2015
In this research, solar cells sensitized with CdS and PbS Nanocrystalline metal sulfides, chemically grown by SILAR, were fabricated and characterized. PV experiments including I-V test in the presence of light and dark,Vocdecay, and Electrochemical impedance spectroscopy were performed on the Cells made through this method in the presence of light and dark and in the time period of 2, 3, 6 and 10 days. From these experiments, the changes in indicators including fill factor, efficiency, open-circuit voltage, short-circuit current, lifetime of electrons in nanostructured anode electrode, recombination resistance and capacitance of the anode electrode-electrolyte interface were observed. Also,...
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
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...
Simple and highly efficient catalyst- and waste-free ring opening of epoxides with Na2S in water, Article Monatshefte fur Chemie ; Volume 141, Issue 3 , 2010 , Pages 323-326 ; 00269247 (ISSN) ; Akbari, E ; Ebrahimi, F ; Saidi, M. R ; Sharif University of Technology
Water was found to be a highly efficient and green catalyst and solvent for ring-opening reaction of epoxides with Na2S at room temperature to give substituted bis(hydroxyethyl)thioethers in high yields
Copper recovery from chalcopyrite concentrate by an indigenous acidithiobacillus ferrooxidans in an air-lift bioreactor, Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 25, Issue 3 , 2006 , Pages 21-26 ; 10219986 (ISSN) ; Vossoughi, M ; Yaghmaei, S ; Jafari, A ; Sharif University of Technology
In this study, effects of solid concentration, temperature, and initial Fe2+ concentration on bioleaching of sulfide mineral (chalcopyrite) obtained from Sarcheshmeh Copper Mine in the region of Kerman located in the south of Iran were investigated. A mesophilic iron oxidizing bacterium, Acidithiobacillus ferrooxidans has been isolated from a typical chalcopyrite copper concentrate of the mentioned mine. Bioleaching experiments were carried out in two batch air-lift bioreactors with recycling stream. One reactor contained 2 liters of medium and 10% (v/v) inoculum while in the other reactor, control bioleaching tests were carried out with sterilized concentrate without inoculum by the...
Enhanced electrochemical activity of Co3O4/Co9S8 heterostructure catalyst for water splitting, Article International Journal of Hydrogen Energy ; 2021 ; 03603199 (ISSN) ; Ahmad, I ; Rashid, N ; Zafar, M. N ; Shehzad, F. K ; ullah, Z ; Ul-Hamid, A ; Nazar, M.F ; Junaid, M ; Faheem, M ; Shafqat, S. S ; Jabeen, U ; Dahshan, A ; Sharif University of Technology
Elsevier Ltd 2021
The dearth of efficient, robust, and economical electrocatalysts for water oxidation is dubiously the key obstacle for renewable energy devices, so synthesis of efficient, and cost-effective metal-based water oxidation catalysts is vital. Herein, Co3O4, Co9S8 catalysts and their heterostructure Co3O4/Co9S8 were synthesized and evaluated as water oxidation electrocatalysts. The characterization of Co3O4, Co9S8, and Co3O4/Co9S8 electrocatalysts was performed using Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction techniques. The heterostructure Co3O4/Co9S8 (1.46 V) exhibited water oxidation electrocatalysis at extremely low onset potential compared to...