Papers by Masoumeh Chamack
Catalysis Letters, Mar 24, 2016
High-quality Co 2 P nanoparticles have been obtained from diphosphine-substituted molecular cobal... more High-quality Co 2 P nanoparticles have been obtained from diphosphine-substituted molecular cobalt clusters anchored into an inorganic matrix. The synthesis was followed stepwise using a wide panel of analytic techniques. The required functionalization of an ordered mesoporous silica matrix of the type SBA-15 was achieved by covalent attachment of the alkoxysilyl-substituted short-bite diphosphine ligand (Ph 2 P) 2 N(CH 2) 3 Si(OMe) 3. Anchoring of the cluster [Co 4 (CO) 10 (µ-dppa)] (dppa) (Ph 2 P) 2 NH) led to an organometallic hybrid mesoporous silica whose thermal treatment led to pure nanocrystalline Co 2 P particles. Compared with the particles obtained in a silica xerogel, those synthesized into the SAB-15 matrix were the most regular in spatial repartition, size, and shape.
Journal of Materials Science, Feb 20, 2020
Keggin-type heteropoly acids are known as active catalysts for oxidative desulfurization of refra... more Keggin-type heteropoly acids are known as active catalysts for oxidative desulfurization of refractory sulfur compounds from fuels. In this work, cesium salts of phosphotungstic acid (HPW) were synthesized based on three different methods: co-precipitation, reversed emulsion, and reversed microemulsion. For reversed microemulsion procedure, the effect of adding order of cesium ion or phosphotungstic acid in the micelle aggregation of sodium dodecyl sulfate (SDS) surfactant was investigated to synthesize different particle sizes of heterogeneous HPW. Obtained products were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and N 2 physical adsorption-desorption techniques. It was observed that all materials obtained via reversed microemulsion method are in organic-inorganic hybrid form which origin from the attachment of SDS to cesium salts of HPW. Oxidative desulfurization of dibenzothiophene from hexane was performed to investigate the activity of the prepared catalysts. The best catalytic activity was achieved by the new organicinorganic hybrid materials obtained via the reversed microemulsion method.
Separation and Purification Technology, Jul 1, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Cesium salts of tungsten-substituted molybdophosphoric acid immobilized onto platelet mesoporous silica: Efficient catalysts for oxidative desulfurization of dibenzothiophene
Chemical Engineering Journal, Nov 1, 2014
Inorganic Chemistry, Jan 10, 2022
The orthorhombic phase of KNbO 3 perovskite has been applied for nitrogen (N 2) photoreduction to... more The orthorhombic phase of KNbO 3 perovskite has been applied for nitrogen (N 2) photoreduction to ammonia (NH 3). However, this material suffers from a low surface area and low ammonia production efficiency under UV light irradiation. To eliminate these barriers, we used a metal−organic framework (MOF), named as TMU-5 (with formula [Zn(OBA)(BPDH) 0.5 ] n •1.5DMF, where H 2 OBA = 4,4′-oxybis(benzoic acid) and BPDH = 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene), for the synthesis of the KNbO 3 @TMU-5 hybrid material. KNbO 3 @TMU-5 achieved a NH 3 production rate of 39.9 μmol•L −1 •h −1 •g −1 upon UV light irradiation, as compared to 20.5 μmol•L −1 *•h −1 •g −1 recorded for KNbO 3 under similar experimental conditions. Using different characterization techniques especially gas adsorption, cyclic voltammetry, X-ray photoelectron spectroscopy, photocurrent measurements, and Fourier transform infrared spectroscopy, it has been found that the higher photoactivity of KNbO 3 @TMU-5 in ammonia production is due to its higher surface area, higher electron−hole separation efficiency, and higher density of negative charges on Nb sites. This work shows that hybridization of conventional semiconductors (SCs) with photoactive MOFs can improve the photoactivity of the SC@MOF hybrid material in different reactions, especially kinetically complex reactions like photoconversion of nitrogen to ammonia. 49 However, there are only a few reports on this class of materials 50 for the photocatalytic reduction of N 2. In this regard, the only 51
Evaluation of the Performance of Concrete by Adding Silica Nanoparticles: A Method Deviation Tolerance Study
Inorganic Chemistry, 2022
The orthorhombic phase of KNbO 3 perovskite has been applied for nitrogen (N 2) photoreduction to... more The orthorhombic phase of KNbO 3 perovskite has been applied for nitrogen (N 2) photoreduction to ammonia (NH 3). However, this material suffers from a low surface area and low ammonia production efficiency under UV light irradiation. To eliminate these barriers, we used a metal−organic framework (MOF), named as TMU-5 (with formula [Zn(OBA)(BPDH) 0.5 ] n •1.5DMF, where H 2 OBA = 4,4′-oxybis(benzoic acid) and BPDH = 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene), for the synthesis of the KNbO 3 @TMU-5 hybrid material. KNbO 3 @TMU-5 achieved a NH 3 production rate of 39.9 μmol•L −1 •h −1 •g −1 upon UV light irradiation, as compared to 20.5 μmol•L −1 *•h −1 •g −1 recorded for KNbO 3 under similar experimental conditions. Using different characterization techniques especially gas adsorption, cyclic voltammetry, X-ray photoelectron spectroscopy, photocurrent measurements, and Fourier transform infrared spectroscopy, it has been found that the higher photoactivity of KNbO 3 @TMU-5 in ammonia production is due to its higher surface area, higher electron−hole separation efficiency, and higher density of negative charges on Nb sites. This work shows that hybridization of conventional semiconductors (SCs) with photoactive MOFs can improve the photoactivity of the SC@MOF hybrid material in different reactions, especially kinetically complex reactions like photoconversion of nitrogen to ammonia. 49 However, there are only a few reports on this class of materials 50 for the photocatalytic reduction of N 2. In this regard, the only 51
Investigation of 12-tungestophosphoric acid immobilized on zirconium modified SBA as catalyst for esterification of glycerol
Journal of Nanomedicine & Nanotechnology, Nov 30, 2017
S transduction of bio-molecular binding events on chip carries profound implications to the outco... more S transduction of bio-molecular binding events on chip carries profound implications to the outcome of a range of biological sensors. This includes biosensors that address both research as well as diagnostic questions of clinical relevance, e.g., profiling of biomarkers, protein expression analysis, drug or toxicity screening and drug-efficacy monitoring. Nanostructured biosensors constitute a promising advance in this direction owing to their ability in catering to better sensitivity, response times and miniaturization. Plasmonic sensors are particularly interesting among nano-biosensors as they exploit light matter interactions in the nanoscale to transduce bio-recognition events with high sensitivity and miniaturized measurement footprints. Examples of plasmonic sensors include localized surface plasmon resonance spectroscopy (LSPR), surface enhanced Raman spectroscopy (SERS) and metal-enhanced fluorescence (MEF). The performance of the plasmonic sensors critically relies on ability to engineer nanoscale geometric attributes at length scales that typically overlap with the size of small proteins. Such geometries invariably introduce constraints on the molecular binding response, thus altering the interaction outcomes, viz. density and kinetics of adsorption, molecular orientations, in a manner that would impact the resulting optical response. A careful engineering of the nanoscale geometries can simultaneously take advantage of EM field enhancements together with molecular interaction within nanoscale geometries. To this end, this project aims at an engineered nanoscale interface with geometry tailored to simultaneously favor molecular adsorption and plasmonic enhancements for application to plasmonic sensors based on surface-enhanced Raman and fluorescence spectroscopies.
Journal of Preventive Medicine, 2020
Introduction: Bisphenol A (BPA) is one of the pollutants of water resources that disrupts the end... more Introduction: Bisphenol A (BPA) is one of the pollutants of water resources that disrupts the endocrine glands and is resistant to biodegradation. This study aimed to evaluate the performance of photocatalytic process using Fe2O3/ZnO in the presence of visible light for degradation of BPA in contaminated water. Methods: A descriptive-analytical study in batch mode was performed on synthetic contaminated water samples made in the laboratory. In this study Fe2O3/ZnO catalyst was used to decompose BPA in the presence of visible light. Moreover, the effect of some parameters such as solution pH, catalyst dose, BPA concentration, and radical scavengers on removal efficiency was investigated. The catalyst's decomposition kinetics and surface properties were also determined using XRD, SEM, DRS, EDX, and BET techniques. Results: BET analysis showed that the Fe2O3/ZnO catalyst's surface area was 15.86 m 2 /g, and the band-gap was 2.7 eV. The highest BPA removal efficiency was obtained at neutral pH, which, considering the interpretation of pKa of BPA and pHpzc of catalyst, seems reasonable. Moreover, with increasing the catalyst dose to 0.04 g/L, BPA removal efficiency increased, and this catalyst dose was selected as the optimum dose. The removal efficiency of BPA was decreased with increasing the initial concentration of BPA. The photodegradation of BPA fits pseudo-first-order degradation kinetics, and by increasing the initial concentration of BPA from 10 to 100 mg/L, the kobs decreased from 0.012 min-1 to 0.0022 min-1. Radical scavenger tests showed that hydroxyl radical (HO •) and generated holes (h +) play the main role in the degradation of BPA. Conclusion: Considering the high photocatalytic performance of the Fe2O3/ZnO in the presence of visible light, it is recommended for the decomposition of persistant organic compounds in contaminated water.
Nanostructures of magnesium oxide is one of the most attractive materials which have shown variou... more Nanostructures of magnesium oxide is one of the most attractive materials which have shown various applications in many aspects of industries. So, finding a controllable and inexpensive technique to produce desirable nanostructures of MgO is valuable. In this work, magnesium oxide (MgO) with different morphologies was successfully prepared via a simple solid-state method. The molar ratio of sodium hydroxide to magnesium salt precursor was obtained 1 to 8. Furthermore, the effect of different magnesium precursors (magnesium chloride and magnesium acetate) on the morphology of MgO was investigated. It was shown that adding halide salts (NaX) to the solid-state reaction media, in spite of the noteworthy influence on the product morphology, facilitate the formation of MgO phase from Mg(OH)2. The synthesized magnesium oxide particles were characterized by Fourier transform infrared (FTIR) spectrometer, scanning electron microscope (SEM) and X-ray diffraction (XRD). Synthesized magnesium ...
Synthesis, Crystal Structure, and DFT Insight of a New Trigonal Bipyramidal Zinc(II) Complex
Journal of Structural Chemistry, 2021
Bithiazole is considered as a domain of bleomycin which is countered as a chemotherapeutic drug t... more Bithiazole is considered as a domain of bleomycin which is countered as a chemotherapeutic drug to treat many types of cancer. Hence, the trend towards the design of model compounds containing the bithiazole moiety is increased recently. In this regard, the 2,2′-diamino-5,5′-dimethyl-4,4′-bithiazole organic ligand (L) is synthesized via a condensation reaction of 3,4-diaminobenzophenone with 2,3-butanedione monoxime. Moreover, its zinc(II) complex [Zn(L)3](NO3)2CH3OH (ZnL3) is synthesized and subsequently characterized by various analytical techniques, including Infrared spectroscopy, proton nuclear magnetic resonance, carbon nuclear magnetic resonance, thermal gravimetric-differential thermal analysis, and single crystal X-ray diffraction. Based on single crystal X-ray data, the ZnL3 complex belongs to the triclinic system with the space group P-1. In ZnL3, one of L ligands acts as a monodentate ligand to form the five-coordinated Zn(II) complex, giving a distorted trigonal bipyramidal geometry around the metal atom. Finally, UV-Vis and fluorescence spectroscopy is used to investigate the photophysical properties of the material explained via density functional theory.
Separation and Purification Technology, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Applied Organometallic Chemistry, 2017
A novel light-active magnetic Pd complex as a photocatalyst was prepared through bonding organome... more A novel light-active magnetic Pd complex as a photocatalyst was prepared through bonding organometallics to mesoporous silica channels formed on the surface of silica-coated iron oxide nanoparticles. The nanocomposite (denoted as Fe 3 O 4 @SiO 2 @m-SiO 2 @PDA-Pd(0); PDA = 1,10-phenanthroline-2,9-dicarbaldehyde) is more efficient and has higher photocatalytic capability in the degradation of 2,4dichlorophenol under visible light irradiation compared with virgin Pd complex (PDA-Pd). This noteworthy photodegradation activity can be due to the high dispersion of Pd nanoparticles. High yield, low reaction time and non-toxicity of the catalyst are the main merits of this protocol. Also magnetic separation is an environmentally friendly alternative method for the separation and recovery of the catalyst, since it minimizes the use of solvents and auxiliary materials, reduces operation time and minimizes catalyst loss by preventing mass loss and oxidation. The produced Pd catalyst was characterised using various techniques. Furthermore, transmission electron microscopy characterization was used for determining the structural properties of the Pd nanocatalyst. KEYWORDS 2,4-dichlorophenol, magnetic Pd photocatalyst, visible light irradiation 1 | INTRODUCTION Chlorophenols, which are widely used for producing various compounds in the chemical industry, are considered as harmful organic pollutants in water because of their toxicity and harmful effects on the human nervous system. [1] Hence, many studies have been conducted to investigate how to degrade and remove these harmful pollutants from wastewater. The stable C─Cl bond, which makes them harmful, is also responsible for their persistence and formation of highly toxic by-products during their degradation via advanced oxidation processes. [2] So, heterogeneous photocatalysis systems which can completely mineralize chlorinated phenols in the presence of solar radiation as source of energy and air as oxidant have received much interest. [3-5]
Journal of Materials Science, 2020
Keggin-type heteropoly acids are known as active catalysts for oxidative desulfurization of refra... more Keggin-type heteropoly acids are known as active catalysts for oxidative desulfurization of refractory sulfur compounds from fuels. In this work, cesium salts of phosphotungstic acid (HPW) were synthesized based on three different methods: co-precipitation, reversed emulsion, and reversed microemulsion. For reversed microemulsion procedure, the effect of adding order of cesium ion or phosphotungstic acid in the micelle aggregation of sodium dodecyl sulfate (SDS) surfactant was investigated to synthesize different particle sizes of heterogeneous HPW. Obtained products were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and N 2 physical adsorption-desorption techniques. It was observed that all materials obtained via reversed microemulsion method are in organic-inorganic hybrid form which origin from the attachment of SDS to cesium salts of HPW. Oxidative desulfurization of dibenzothiophene from hexane was performed to investigate the activity of the prepared catalysts. The best catalytic activity was achieved by the new organicinorganic hybrid materials obtained via the reversed microemulsion method.
Catalysis Communications, 2018
Zirconium-modified mesoporous silica (Zr-S) was synthesized as a new promising catalyst for the a... more Zirconium-modified mesoporous silica (Zr-S) was synthesized as a new promising catalyst for the acetylation reaction of glycerol. In the presence of Zr-S catalyst, the selectivity to desired products (TAG and DAG) reached 91%, with a complete conversion of glycerol. Moreover, 12tungstophosphoric acid (H 3 PW 12 O 40) was immobilized onto Zr-S surface, and the effect of acid strength of catalysts on this reaction was investigated by NH 3-temperature programmed desorption (NH 3-TPD) technique. Synthesized materials were characterized by various analytical techniques: X-ray powder diffraction, scanning electron microscopy, N 2 adsorption-desorption, and inductively coupled plasma spectroscopy.
Catalytic performance of vanadium-substituted molybdophosphoric acid supported on zirconium modified mesoporous silica in oxidative desulfurization
Chemical Engineering Research and Design, 2015
ABSTRACT
Cesium salts of tungsten-substituted molybdophosphoric acid immobilized onto platelet mesoporous silica: Efficient catalysts for oxidative desulfurization of dibenzothiophene
Chemical Engineering Journal, 2014
Inorganic chemistry, Jan 2, 2018
Polyoxometalates (POMs) and in particularly Keggin heteropolytungstates are much studied and comm... more Polyoxometalates (POMs) and in particularly Keggin heteropolytungstates are much studied and commercially important catalysts for dioxygen-based oxidation processes. The rate-limiting step in many POM-catalyzed O-based oxidations is reoxidation of the reduced POM by O. We report here that this reoxidation process, as represented by the one-electron-reduced Keggin complexes POM(α-PWOand α-SiVWO) reacting with O, is efficiently catalyzed by a combination of copper and iron complexes. The reaction kinetics and mechanism have been comprehensively studied in sulfate and phosphate buffer at pH 1.8. The catalytic pathway includes a reversible reaction between Cu(II) and Fe(II), followed by a fast oxidation of POMby Fe(III) and Cu(I) by Oto regenerate Fe(II) and Cu(II). The proposed reaction mechanism quantitatively describes the experimental kinetic curves over a wide range of experimental conditions. Since the oxidized forms, α-PWOand α-SiVWO, are far better oxidants of organic substrates...
Nanochemistry Research, 2018
Nanostructures of magnesium oxide is one of the most attractive materials which have shown variou... more Nanostructures of magnesium oxide is one of the most attractive materials which have shown various applications in many aspects of industries. So, finding a controllable and inexpensive technique to produce desirable nanostructures of MgO is valuable. In this work, magnesium oxide (MgO) with different morphologies was successfully prepared via a simple solid-state method. The molar ratio of sodium hydroxide to magnesium salt precursor was obtained 1 to 8. Furthermore, the effect of different magnesium precursors (magnesium chloride and magnesium acetate) on the morphology of MgO was investigated. It was shown that adding halide salts (NaX) to the solid-state reaction media, in spite of the noteworthy influence on the product morphology, facilitate the formation of MgO phase from Mg(OH)<sub>2.</sub> The synthesized magnesium oxide particles were characterized by Fourier transform infrared (FTIR) spectrometer, scanning electron microscope (SEM) and X-ray diffraction (XRD). Synthesized magnesium oxide particles were used to remove congored dye from waste water.
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Papers by Masoumeh Chamack