Papers by Maryam Kargar Razi
international journal of nano dimension, Dec 1, 2010
According to the unique properties and many applications of nano silver powder, it was prepared f... more According to the unique properties and many applications of nano silver powder, it was prepared from acid leaching tail solution. The low value residual gold and silver ions were occurred with fellow heavy metals as pollutants (Fe 2+ , Cu 2+ and Zn 2+) in acid leaching tail solution in Mouteh gold mine in Iran. Preparation of nano silver particles was achieved in two steps: first, by addition of ammonia as a separation step and second by using different reagents as precipitation and extraction steps. Different controlled parameters were including pH, residence time and temperature, mixing time, and reducing reagents to metals molar ratio. Acid leaching process was carried out with sulphuric and nitric acid via suitable reductants. In order to remove copper, zinc, and silver ions from solution, all of the conditions were controlled. The optimum conditions for preparation of nano silver powder with less than 90 nm were pH 10.5, hydrazine/methanol to silver molar ratio of 3 to 4, and reduction time of 5 min in 45ºC. The results were evaluated via SEM, A.A and UV-Vis spectroscopy analytical methods.
In this investigation, the adsorption behavior of natural phosphate rock and it's concentrate... more In this investigation, the adsorption behavior of natural phosphate rock and it's concentrate with respect to Fe 3+ ،Ni 2+
ChemInform, Sep 1, 2016
An Environmentally Friendly Oxidation of Thiols to Disulfides by Calcium Hypochlorite and Montmor... more An Environmentally Friendly Oxidation of Thiols to Disulfides by Calcium Hypochlorite and Montmorillonite K10 in Hexane.-Aromatic, aliphatic and alicyclic thiols (13 examples) can be readily oxidized quantitatively to the corresponding disulfides under the mild and neutral con
In many cases in concentrate factory of Sarcheshmeh copper co., the grade of copper in molibdenit... more In many cases in concentrate factory of Sarcheshmeh copper co., the grade of copper in molibdenite concentrate exceeds its permissible limits. This causes economic reduction in value of product. So, with sodium cyanide addition, the copper content in concentrate is controlled. Sodium cyanide is very toxic and environmentally hazardous. In this investigation, studying the feasibility use of microorganism ability is considered. At first after sampling of molibdenite concentrate of Sarcheshmeh Co., and chemical and mineralogical of obtained samples were under the bio-leaching process by mesophile bacteria mix culture of,)acidi thio bacilous thiooxidance acidi thibacilous ferroxidanse and leptosperilom feroxidance(and Thermophile)acidianous berili ,sulfo-lobous acido caldarious(bacteria.In this investigation, bio-leaching reactor and microbial study in shaking methods are considered. The results of microbial methods in shaking flasks, copper removal by mesophile bacteria is 55% and by thermophile bacteria is 75%. The results in bioleaching reactor showed, the rate of copper removal from molibdenite concentrate by mesophile bacteria is 50%)temp. 35 °C, pH =2, solid % =10 and bacterial inoculation =12%(and by thermophile bacteria is 60%)temp.65° C, pH=2, solid%=10 and bacterial inoculation=12%(. Therefore, the use of bacteria is important for copper removal from molybdenite concentrate. This approach also prevents contamination of the environment.
Research Square (Research Square), Nov 17, 2022
Aluminum uoride (nAF) nanoparticles were synthesized by the sol-gel synthesis into a glass reacto... more Aluminum uoride (nAF) nanoparticles were synthesized by the sol-gel synthesis into a glass reactor. The effect of alteration in precursor gel preparation on the nano-sized area was studied. The morphology of crystals has been changed by modi ed on precursor gel. The PVC/NiAl 2 O 3 /AlF 3 nanocomposite was successfully prepared and characterized by FT-IR, XRD, HRTEM, TG-DTG and SEM techniques. The size of crystals decreased from 15 to 20 nanometers when the aging time of precursor gel was changed from 5 to 12 h. Catalytic activity results show that the as-prepared nanocomposite is as an e cient catalyst. A solvothermal method has been successfully introduced and applied for catalyst e ciency. This study development exhibited that PVC/NiAl 2 O 3 /AlF 3 nanocomposite as an effective catalyst for the synthesis of some organic derivatives.
international journal of nano dimension, Jul 1, 2010
Journal of Experimental Nanoscience, May 18, 2012
Iron titanate nanopowders with a particle size range of 48-70 nm could be obtained after calcinat... more Iron titanate nanopowders with a particle size range of 48-70 nm could be obtained after calcinations of the dried gel at 900 C for 2 h. Fe 2 TiO 5 indicates a ferrimagnetic-paramagnetic behaviour, as evidenced by using vibrating sample magnetometer at room temperature. In the temperature range of 25-300 C the empirical equation of the heat capacity C p (J/mol K) ¼ À692.328 þ 1.39 T þ 3.757 Â 10 7 /T 2 for Fe 2 TiO 5 was determined from differential scanning calorimetry. Direct optical band gap of Fe 2 TiO 5 was calculated using the Tauc model by UV-Vis diffuse reflectance spectroscopy. Band gap energy of Fe 2 TiO 5 was determined as 1.95 eV.
international journal of nano dimension, Jun 1, 2011
In this study, selenium was recovered from an industrial dust. After the purification process, th... more In this study, selenium was recovered from an industrial dust. After the purification process, the researchers were able to prepare selenium micro powder. The objective of this study was to prepare selenium nano particles by water solution phase method from the micro powders. The results showed that selenium micronized powder and nano particles had high purity. The obtained nanoparticles were tube shaped with 20 nm size.
Journal of Molecular Structure, May 1, 2014
h i g h l i g h t s Theoretical study of the adsorption of aldehydes on ZnO nanoparticles. Hydrog... more h i g h l i g h t s Theoretical study of the adsorption of aldehydes on ZnO nanoparticles. Hydrogen-terminated ZnO nanoclusters and graphene-like nanosheets are considered. Densities of states of the aldehydes into ZnO surfaces are calculated. Effect of aldehyde chain length was investigated.
Journal of Nanoanalysis, May 22, 2018
Photocatalysis has attracted significant attention as a potential issue for degradation of toxic ... more Photocatalysis has attracted significant attention as a potential issue for degradation of toxic organic pollutants such as Congo Red. In this research spherical Pure ZnO nano particles and Ni-Co-ZnO nano composites (Zn0.95Ni0.04Co0.01O, Zn0.95Ni0.025Co0.025O and Zn0.95Ni0.01Co0.04O) have been synthesized by precipitation method. X- ray diffraction, Fourier transform Infra Red ,field emission scanning electron microscopy, EDX and ICP analysis confirmed the structure and composition of samples. The x-ray diffraction analysis (XRD) showed that all samples prepared were of Wurtzite structure and average crystal size of 17nm. Field emission scanning electron microscopy (FESEM) analysis revealed the spherical shape of all samples. The Fourier transform infrared spectroscopy (FT-IR) revealed bands at 435 cm-1, 480 cm-1 and 525 cm-1 are related to Zn-O bonds , related to the stretching vibrating bonds of ZnO. The results illustrated the Ni and Co ions substituted the Zn ions in ZnO crystal lattice successfully. The results showed that some of doped Ni-Co ZnO exhibit enhanced photocatalytic activity , as compared to pure ZnO. Kinetic of de-colorization process for all photo-catalysts followed psedu first order. In degradation process The best photocatlyst was (Zn0.95Ni0.04Co0.01O).
ChemInform, Jun 1, 2015
ChemInform Abstract Durch Zugabe von Siliciumtetrachlorid (II) zu einer schwach siedenden Suspens... more ChemInform Abstract Durch Zugabe von Siliciumtetrachlorid (II) zu einer schwach siedenden Suspension von Natriumfluorid (I) in Acetonitril entsteht unter absolut wasserfreien Bedingungen in 80%iger Ausbeute Siliciumtetrafluorid (III), das in 99,9%iger Reinheit anfällt.
international journal of nano dimension, Dec 1, 2010
CoTiO 3-clay nano-composites were synthesized via a conventional sol-gel method; the gel was calc... more CoTiO 3-clay nano-composites were synthesized via a conventional sol-gel method; the gel was calcinated at 500-800°C for 2 hours. The presence of rhombohedra phase of CoTiO 3 in clay matrix was confirmed by XRD, FTIR , SEM. Cobalt titanate-clay nano-composites were prepared with 5-20%(w/w) by sol-gel method. The spectra results were investigated at 20% (w/w) concentration .The optimum condition for nano-composite preparation in 20 %(w/w) at 600°C is obtained.
Journal of Inorganic and Organometallic Polymers and Materials, Mar 16, 2019
In this study, a novel nanocatalyst (MgAl 2 O 4 @SiO 2-PTA) was recommended for the oxidation of ... more In this study, a novel nanocatalyst (MgAl 2 O 4 @SiO 2-PTA) was recommended for the oxidation of benzylic alcohols. The resulting nanoparticles were characterized by spectroscopic and microscopic methods, such as X-ray diffraction, SEM, FT-IR, EDX, ICP-AES, and Brunauer-Emmett-Teller surface area analysis. In this paper, magnesium aluminate spinel (MgAl 2 O 4), used as the supporting catalyst, provides the recycling and reusing the catalyst and also increases the efficiency of the reaction. The nanocomposite was investigated as a catalyst for the selective oxidation of alcohols to the corresponding carbonyl compounds with hydrogen peroxide as oxidant and water as a solvent. Primary alcohols were converted to aldehydes but secondary alcohols were converted to ketones. Benzylic alcohols have better oxidative reactions than aliphatic alcohols. Among the oxidation reactions of the benzylic alcohols investigated in this project, the oxidation reaction of 1-phenylethanol to acetophenone was more efficient than other reactions (98%). This nanocatalyst is environmentally friendly because it could be recovered by simple filtration. The catalyst was used five times successfully without any changes or loss of its high catalytic activity.
In this paper, titanium dioxide nano-particles were synthesized by sol-gel method in acidic atmos... more In this paper, titanium dioxide nano-particles were synthesized by sol-gel method in acidic atmosphere. The microstructure, morphology, optical band gap, and hydrophilicity of the sample were studied. Optical band gap of titanium dioxide was probed via Diffuse Reflectance Spectra (DRS) and contact angle (CA) was measured to investigate surface activity. XRD analysis was used to study crystallinity of the samples. Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) was also performed. The results presented high crystallinity of particles with average particle size of ~21nm. Very small nano-particles were obtained (as small as 7nm). The obtained optical band gap of the sample was determined which was 3.35 eV with direct linear fitness in Tauc relation. Contact angle indicated super- hydrophilicity after 40 minutes under UV-Radiation.
Research on Chemical Intermediates, 2019
In this research, a recoverable catalyst (MgAl 2 O 4 @SiO 2-PTA) was prepared by a simple utiliza... more In this research, a recoverable catalyst (MgAl 2 O 4 @SiO 2-PTA) was prepared by a simple utilization method. The prepared catalyst was characterized by XRD, FT-IR, SEM, EDX, ICP-AES, and BET techniques. The average crystallite size of MgAl 2 O 4 was calculated to be 40 nm by the Debye-Scherrer formula. The nanocomposite was examined as a heterogeneous catalyst for synthesis of α-aminophosphonates under solvent-free conditions at room temperature. In this process, magnesium aluminate spinel (MgAl 2 O 4), used as the base and supporting catalyst for H 3 PW 12 O 40 (PTA), provides the recycling and reusing of the catalyst and also increases the efficiency of the reaction, which is due to the increase in the surface/volume ratio. In order to obtain optimal conditions, the synthesis of α-aminophosphonates reactions was investigated with different solvents and catalysts. The results showed that α-aminophosphonate prepared from the benzaldehyde and aniline reaction has higher efficiency and a shorter time than other reactions. The catalyst was recovered by simple filtration, and it can be recycled for at least five successive times without loss of catalytic activity.
RSC Advances, 2015
An efficient method for the preparation of 1,3,5-triarylbenzenes. Natural surface-modified NCP as... more An efficient method for the preparation of 1,3,5-triarylbenzenes. Natural surface-modified NCP as a new and reusable catalyst. Using solvent-free conditions.
Journal of Nanostructures, 2012
MnTiO 3-Zeolite-Y nanocomposites were synthesized with 5-10-20% (w/w) of MnTiO 3 by stearic acid ... more MnTiO 3-Zeolite-Y nanocomposites were synthesized with 5-10-20% (w/w) of MnTiO 3 by stearic acid gel method. Then, the gels were calcined at 900 °C for 4 hours and the resulted spectra were investigated at 20% (w/w) concentration. Also, the presence of rhombohedral phase of MnTiO 3 in Zeolite-Y matrix was confirmed by XRD, SEM, EDX and BET. The VSM results showed the antiferromagnetic properties for the 20% nanocomposite. The photocatalytic activity of the nanocomposites was finally evaluated by degradation of methylene blue and calcon reagents in aqueous solution.
Nashrieh Shimi va Mohandesi Shimi Iran, Jan 21, 2020
Aluminum fluoride (nAF) nanoparticles were synthesized by the sol gel synthesis into a glass reac... more Aluminum fluoride (nAF) nanoparticles were synthesized by the sol gel synthesis into a glass reactor. The effect of alteration in precursor gel preparation on the nano area was studied. The morphology of crystals has been changed by modified on precursor gel. Then the PVC/NiAl2O3/AlF3 nanocomposite has been successfully prepared and characterized by FT-IR, XRD, TG-DTG and SEM techniques. The size of crystals decreased from 15 to 20 nanometers when the aging time of precursor gel was changed from 5 to 12 h. Catalytic activity results show that the as-prepared nanocomposite is as an efficient catalyst. This study development and could be explored that PVC/NiAl2O3/AlF3 nanocomposite as a new and effective catalyst for synthesis of some organic derivatives.
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Papers by Maryam Kargar Razi