Synthesis and Catalytic Properties of CoFe2O4/Fe2O3 Nanosized Composite Material

2021 ◽  
Vol 316 ◽  
pp. 56-61
Author(s):  
N.P. Shabelskaya ◽  
M.A. Egorova ◽  
E.V. Vasilieva
Keyword(s):  
Hydrogen Peroxide ◽  
Composite Material ◽  
Catalytic Activity ◽  
Oxidative Degradation ◽  
Average Crystallite Size ◽  
X Ray ◽  
Cell Parameters ◽  
Reaction Rate Increase ◽  
Developed Surface ◽  
Degradation Reaction

The present research is devoted to the formation process of a nanoscale composite material with the composition of CoFe2O4/α-Fe2O3. The synthesized material has been studied by the following methods: x-ray phase analysis and scanning electron microscopy. The produced sample is analyzed to be a CoFe2O4 cabic spinel with a unit cell parameters of a = 0.8394 nm and α-Fe2O3. The average crystallite size of the resulting samples, determined by the Debye-Scherrer equation, is 4.8 nm for the cobalt (II) ferrite and 7.9 nm for α-Fe2O3. Reaction rate increase is determined by the incease in hydrogen peroxide amount in the solution. The synthesized composite material is found to exhibit increased catalytic activity in the oxidative degradation reaction of organic dye by hydrogen peroxide. The catalytic activity is established to be particularly high, when the process is occurring in acidic medium. The obtained samples have a highly developed surface and may be of interest as catalysts, adsorbents.

scholarly journals Expression, purification, crystallization and preliminary crystallographic analysis of human myotubularin-related protein 3

2014 ◽  
Vol 70 (9) ◽  
pp. 1240-1243
Author(s):  
Ji Young Son ◽  
Jee Un Lee ◽  
Ki-Young Yoo ◽  
Woori Shin ◽  
Dong-Won Im ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Catalytic Domain ◽  
Family Members ◽  
Large Family ◽  
Crystallographic Analysis ◽  
Related Protein ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Related Proteins

Myotubularin-related proteins are a large family of phosphatases that have the catalytic activity of dephosphorylating the phospholipid molecules phosphatidylinositol 3-phosphate and phosphatidylinositol 3,5-bisphosphate. Each of the 14 family members contains a phosphatase catalytic domain, which is inactive in six family members owing to amino-acid changes in a key motif for the activity. All of the members also bear PH-GRAM domains, which have low homologies between them and have roles that are not yet clear. Here, the cloning, expression, purification and crystallization of human myotubularin-related protein 3 encompassing the PH-GRAM and the phosphatase catalytic domain are reported. Preliminary X-ray crystallographic analysis shows that the crystals diffracted to 3.30 Å resolution at a synchrotron X-ray source. The crystals belonged to space groupC2, with unit-cell parametersa= 323.3,b= 263.3,c= 149.4 Å, β = 109.7°.

scholarly journals Synthesis and properties of composite material CoFe2O4/C

2020 ◽  
Vol 81 (4) ◽  
pp. 184-189
Author(s):  
N. P. Shabelskaya ◽  
M. A. Egorova ◽  
G. M. Chernysheva ◽  
A. N. Saliev ◽  
A. N. Yatsenko ◽  
...  
Keyword(s):  
Composite Material ◽  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Average Crystallite Size ◽  
Nitrogen Adsorption ◽  
Lattice Parameter ◽  
Transition Elements ◽  
Developed Surface

Scientific interest in the processes of forming the structure of magnetic spinels and composites based on them is due to the possibility of synthesis of materials with multifunctional properties. The process of formation of cobalt (II) nanocrystalline ferrite and CoFe2O4/C composite material is studied. The mechanism of formation of structure of materials including a stage of formation of hydroxides of transition elements, precursors on the basis of complex connections of cations of iron and cobalt with citric acid and their subsequent destruction at heating is offered. The synthesized materials were characterized by x-ray phase analysis, electron microscopy, low-temperature nitrogen adsorption, Debye-Scherrer methods. It is shown that cobalt (II) ferrite has a developed surface, the value of the surface area according to the BET method is 16 m2/g, the average size of the crystallites determined by the Debye-Scherrer equation is 4.0 nm. Activated carbon with a specific surface area of 685 m2/g was used to prepare the composite material. The resulting composite material has a surface area of 222 m2/g, the average crystallite size of 1.1 nm. Cobalt (II) ferrite, included in the composition of the composite material CoFe2O4/C, has a slightly higher value of the lattice parameter, compared with pure cobalt (II) ferrite, which is associated with a decrease in the degree of spinel inversion. The synthesized composite material was tested in the process of adsorption of copper (II) cations from an aqueous solution. It is shown that CoFe2O4/C exhibits an increased adsorption capacity for copper (II) cations in comparison with pure activated carbon, despite a decrease in the specific surface area. The result is explained by the involvement of cobalt (II) ferrite in the adsorption process. The obtained materials may be of interest as catalysts, adsorbents.

scholarly journals OBTAINING AND PHYSICO-CHEMICAL PROPERTIES OF MATERIALS BASED ON EXPANDED VERMICULITES OF VARIOUS COMPOSITIONS

2018 ◽  
Vol 61 (6) ◽  
pp. 76
Author(s):  
Alexander V. Kalashnik ◽  
Sergey G. Ionov
Keyword(s):  
Hydrogen Peroxide ◽  
Chemical Properties ◽  
Decomposition Reaction ◽  
Chemical Compositions ◽  
Thermal Treatments ◽  
X Ray ◽  
Expanded Vermiculite ◽  
Physico Chemical ◽  
Developed Surface ◽  
Properties Of Materials

Optimal conditions for chemical and thermal treatments of natural vermiculites from various deposits were determined. The aim of obtaining expanded vermiculites with a minimum bulk density was pursued. Optimum temperature for producing thermal expanded vermiculites was 700 °C. According to scanning electron microscopy chemical expanded vermiculite has more developed surface in comparison with thermal expanded vermiculite. Chemical composition of natural vermiculites of various deposits and expanded vermiculites based on them was defined by X-ray fluorescence. It was shown that the vermiculite of the Tatar deposit contains a large amount of iron distributed over the surface. As a result, the vermiculite from Tatarstan can not be modified by hydrogen peroxide because of the active decomposition reaction of hydrogen peroxide on the surface of vermiculite. It was established that the chemical compositions of natural vermiculites as well as expanded vermiculites based on them do not differ. According to Mössbauer spectroscopy the ratio Fe(II)/Fe(III) in natural vermiculate was 1:4 and in thermal expanded vermiculite was 1:8. It should be noted that chemical expanded vermiculate contains only Fe(III). According to X-ray phase analysis the phase composition of natural vermiculite changes at 350 °C. It was defined that natural vermiculite and thermal expanded vermiculite after adsorption of moisture from the air have the same position of the X-ray maximum. When natural vermiculite was heated two areas of water loss were observed by the thermogravimetric analysis. The anisotropy of tensile strength for samples of the same density taken along and across the rolling axis of vermiculite foil obtained by pressing expanded vermiculite without a binder was described. The thermal conductivity coefficient of vermiculite foil was determined. This makes it possible to use the material as heat shield and fire protector.Forcitation:Kalashnik A.V., Ionov S.G. Obtaining and physico-chemical properties of materials based on expanded vermiculites of various compositions. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 6. P. 76-82

scholarly journals Obtaining a composite material based on cobalt (II) ferrite for purification of aqueous solutions

2019 ◽  
Vol 140 ◽  
pp. 02002
Author(s):  
Nina Shabelskaya ◽  
Marina Egorova ◽  
Galina Chernysheva ◽  
Vladimir Semchenko
Keyword(s):  
Composite Material ◽  
Aqueous Solutions ◽  
Crystallite Size ◽  
Surface Area ◽  
High Surface ◽  
Average Crystallite Size ◽  
Oxide Systems ◽  
Industrial Enterprises ◽  
Developed Surface ◽  
Bet Method

In modern society, the detrimental effect of industrial production on the environment is intensifying. Contaminated wastewaters of industrial enterprises deteriorate the environmental situation and violate the ecosystem stability. One of efficient methods of dealing with harmful impurities in wastewater is to remove them using adsorption active materials. Oxide systems of ferrites of transition elements are one example of materials with multifunctional properties. The possibility of synthesizing nanoscale cobalt (II) ferrite and a composite material based on it with the CoFe2O4/C composition was studied. The obtained materials were studied using X-ray phase analysis, electron microscopy (SEM), and the BET method of low-temperature nitrogen adsorption. It was established that cobalt (II) ferrite has a developed surface (the surface area measured by the BET method is 16 m2/g, the average crystallite size obtained by the Debye-Scherrer method is 4.0 nm). The mechanism of CoFe2O4 structure formation is considered. The composite material CoFe2O4/C is characterized by a high surface area (222 m2/g, average crystallite size of 1.1 nm) and exhibits increased adsorption ability with respect to copper (II) cations from aqueous solutions. The obtained results are of interest as materials for purification of aqueous solutions.

scholarly journals Zeolite-X Encapsulated Ni(II) and Co(II) Complexes with 2,6-Pyridine Dicarboxylic Acid as Catalysts for Oxidative Degradation of Atenolol in an Aqueous Solution

2021 ◽  
Author(s):  
Fatemeh Hassani ◽  
Mahboubeh A. Sharif ◽  
Masoumeh Tabatabaee ◽  
Mahboobeh Mahmoodi
Keyword(s):  
Catalytic Activity ◽  
Dicarboxylic Acid ◽  
Dipicolinic Acid ◽  
Oxidative Degradation ◽  
Optimal Conditions ◽  
Zeolite X ◽  
Pyridine Dicarboxylic Acid ◽  
Catalyst Temperature ◽  
Ft Ir ◽  
Degradation Reaction

Abstract Complexes of Co (II) and Ni (II) with dipicolinic acid, 2,6-pyridine dicarboxylic acid (PydcH2) have been synthesized in the NaX (zeolite-X) nanopores. The formation of zeolite X encapsulated Co(II) and Ni(II) complexes ([M(pydcH)2]-NaX, where M = Co(II) and Ni(II]) were confirmed using spectroscopic methods of FT-IR, elemental analysis, XRD, FE-SEM, and TEM. It was affirmed that the encapsulation of complexes in NaX pores was performed without changes in the structure and shape of the zeolite. The oxidative degradation reaction of atenolol with hydrogen peroxide as an oxidant was performed in the presence of synthesized [M(pydcH)2]-NaX nanocomposites to study their catalytic activity. Therefore, oxidation of atenolol was performed under different conditions of catalyst, temperature, and time. Under optimal conditions, catalysts [Co(pydcH)2]-NaX and [Ni(pydcH)2]-NaX showed 82.3% and 71.1% activity of atenolol oxidation, respectively. These catalysts were stable after recovery and were used three more times. The results showed that these catalysts were reusable and had a reduction in the catalytic activity of less than ten percent.

scholarly journals High Catalytic Activity of Heterometallic (Fe6Na7 and Fe6Na6) Cage Silsesquioxanes in Oxidations with Peroxides

2017 ◽  
Author(s):  
Alexey I. Yalymov ◽  
Alexey N. Bilyachenko ◽  
Mikhail M. Levitsky ◽  
Alexander A. Korlyukov ◽  
Victor N. Khrustalev ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Hydroxyl Radicals ◽  
Acetonitrile Solution ◽  
High Catalytic Activity ◽  
X Ray ◽  
Complex Ii ◽  
Alkyl Hydroperoxides ◽  
Catalytically Active ◽  
Very High

Two types of heterometallic (Fe(III),Na) silsesquioxanes [Ph5Si5O10]2[Ph10Si10O21]Fe6(O2‒)2Na7(H3O+)(MeOH)2(MeCN)4.5.1.25(MeCN), I, and [Ph5Si5O10]2[Ph4Si4O8]2Fe6Na6(O2‒)3(MeCN)8.5(H2O)8.44, II, were obtained and characterized. X-Ray studies established distinctive structures of both products, with pair of Fe(III)-O-based triangles surrounded by siloxanolate ligands, giving fascinating cage architectures. Complex II proved to be catalytically active in the formation of amides from alcohols and amines, thus becoming a rare example of metallasilsesquioxanes performing homogeneous catalysis. Benzene, cyclohexane and other alkanes, as well as alcohols, can be oxidized in acetonitrile solution to phenol, the corresponding alkyl hydroperoxides and ketones, respectively, by hydrogen peroxide in air in the presence of catalytic amounts of complex II and trifluoroacetic acid. Thus, the cyclohexane oxidation at 20 °C gave oxygenates in very high for alkanes yield (48% based on alkane). The kinetic behaviour of the system indicates that the mechanism includes the formation of hydroxyl radicals generated from hydrogen peroxide in its interaction with diiron species. The latter are formed via monomerization of starting hexairon complex with further dimerization of the monomers.

scholarly journals Sol-Gel Synthesized MagneticMnFe2O4Spinel Ferrite Nanoparticles as Novel Catalyst for Oxidative Degradation of Methyl Orange

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Linfeng Zhang ◽  
Yuanxin Wu
Keyword(s):  
Catalytic Activity ◽  
Methyl Orange ◽  
Surface Area ◽  
Spinel Ferrite ◽  
Sol Gel ◽  
Oxidative Degradation ◽  
Ferrite Nanoparticles ◽  
Magnetic Response ◽  
X Ray ◽  
Degradation Of Methyl Orange

The MnFe2O4spinel ferrite nanoparticles with sensitive magnetic response properties and high specific surface area were prepared from metal nitrates by the sol-gel process as catalysts for oxidative degradation of methyl orange (MO). The nanoparticles were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), BET surface area analysis, H2-Temperature programmed reduction (H2-TPR), X-ray photoelectron spectra (XPS), and vibration sample magnetometer (VSM). The catalytic activity experimental results showed that the MnFe2O4spinel ferrite nanoparticles possess very high MO degradation activity. It is expected that this kind of MnFe2O4spinel ferrite nanoparticles has a potential application in water treatment fields due to its sensitive magnetic response properties and high catalytic activity.

The Synthesis of Copper(II) Salicylaldiminato Complexes and their Catalytic Activity in the Hydroxylation of Phenol

2007 ◽  
Vol 62 (3) ◽  
pp. 331-338 ◽  
Author(s):  
Juanita L. van Wyk ◽  
Selwyn Mapolie ◽  
Anders Lennartson ◽  
Mikael Håkansson ◽  
Susan Jagner
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Copper Complexes ◽  
Aqueous Media ◽  
Copper Acetate ◽  
The Other ◽  
Hydroxylation Of Phenol ◽  
X Ray ◽  
Ft Ir ◽  
Ph Range

The synthesis of copper(II) salicylaldiminato complexes and their application in the catalytic hydroxylation of phenol is reported. Tetracoordinated copper complexes (Cu(Ln)2) were obtained by reacting the N-phenylsalicylaldimine ligands (HL1 -HL7) with copper acetate in a 2 : 1 mole ratio. The reaction of N-(2,6-diisopropyl)phenyl-3,5-di-tert-butylsalicylaldimine (HL7) with copper acetate in a 1 : 1 mole ratio afforded a dinuclear complex, which was not obtained with the other ligand systems. All complexes were characterized using FT-IR and elemental analysis. X-Ray crystal structures of complexes 2, 5 and 8 have also been obtained. The catalytic activity of these complexes was evaluated in the hydroxylation of phenol using oxygen and hydrogen peroxide as co-oxidants in aqueous media in the pH range 3 - 6. All complexes studied were found to be active for the hydroxylation process over the pH range studied with higher selectivity for catechol formation.

Kinetics Study on the Oxidative Degradation of Cellotriose and Cellotetraose by Hydrogen Peroxide

2012 ◽  
Vol 550-553 ◽  
pp. 2638-2643
Author(s):  
Hong Peng
Keyword(s):  
Hydrogen Peroxide ◽  
Degradation Products ◽  
Chemical Reactivity ◽  
Oxidative Degradation ◽  
Reaction Rates ◽  
Degree Of Polymerization ◽  
Nmr Techniques ◽  
Degradation Reaction ◽  
Higher Temperature ◽  
Main Components

Cellulose is one of the main components of renewable lignocellulosic biomass. Functional cellooligosaccharides obtained from the hydrolysate of cellulose could be used as model compounds to study the chemical reactivity of cellulose. HPLC, 1H NMR and 13C NMR techniques were used to analyze the degradation products of cellotriose and cellotetraose oxided by hydrogen peroxide. Results demonstrated that the main degradation products were oligosaccharides with lower degree of polymerization (DP), glucose, and other products including polyhydroxy acid and ketone. The degradation rate declined with the increment of DP. The degradation of cellotriose and cellotetraose at 60 °C followed a pseudo-first-order rate law, the degradation reaction rates were k3=0.25 h-1 and k4=0.15 h-1. Cellooligosaccharides could be degraded completely at higher temperature and for longer reaction time. Degradation products were also degraded at higher temperature and for longer time. The concentration of degradation products went up with the increase of substrate concentration.

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