scholarly journals Structural, Mineral and Elemental Composition Features of Iron-Rich Saponite Clay from Tashkiv Deposit (Ukraine)

2019 ◽  
Vol 3 (1) ◽  
pp. 10 ◽  
Author(s):  
Halyna Sokol ◽  
Myroslav Sprynskyy ◽  
Alla Ganzyuk ◽  
Victoria Raks ◽  
Bogusław Buszewski
Keyword(s):  
Electron Microscopy ◽  
Mineral Resources ◽  
Total Pore Volume ◽  
Nitrogen Adsorption ◽  
Structural Features ◽  
Narrow Slit ◽  
Porous System ◽  
Transmission Electron ◽  
A Charge ◽  
Adsorption Desorption

Low-temperature nitrogen adsorption–desorption isotherms, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, as well as infrared spectroscopy were used to characterize structural features of raw and acid-treated saponite from Tashkiv deposit of Ukraine. It was determined that raw saponite is predominantly composed of trioctahedral saponite with an admixture of dioctahedral nontronite and associated minerals such as quartz, hematite, and anatase. Raw saponite clay was characterized by a high content of iron (19.3%) and titanium (1.1%). Iron is present in the form of hematite particles, isomorphic replacements in octahedral and tetrahedral sheets of a clay structure, or as a charge-balancing cation in the interlayer space. Titanium is homogeneously dispersed as submicrometer anatase particles. The porous structure of both saponite forms consists of micro-meso porous system with narrow slit mesopores dominating. As a consequence of the acid treatment, the specific surface area increased from 47 to 189 m2 g−1, the total pore volume from 0.134 to 0.201 cm3 g−1, and the volume of the micropores increased sevenfold. Using the data of our research allowed us to utilize these mineral resources wisely and to process saponite more efficiently.

SYNTHESIS, CHARACTERIZATION AND THE APPLICABILITY OF β-CYCLODEXTRINS FUNCTIONALIZED MESOPOROUS SBA-15 MOLECULAR SIEVES

NANO ◽  
2013 ◽  
Vol 08 (05) ◽  
pp. 1350050
Author(s):  
MIN GUAN ◽  
HAI-PENG BI ◽  
ZUYUAN WANG ◽  
SHAOHUA BU ◽  
LING HUANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Molecular Sieves ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Capacities ◽  
Transmission Electron ◽  
Potential Applications ◽  
Adsorption Desorption

Mesoporous silicas SBA-15 are modified with β-Cyclodextrins (β-CD) by simple grafting method. β-CD functionalized SBA-15 was characterized by Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), nitrogen adsorption–desorption measurements, thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). Furthermore, the applicability of it is investigated through studying the adsorption properties of clenbuterol. It showed better adsorption capacities of clenbuterol than pure SBA-15. β-CD functionalized SBA-15 material has the potential applications in the treatment of clenbuterol contamination in food and environment science.

scholarly journals Oxidative Coupling of Methane over Mn2O3-Na2WO4/SiC Catalysts

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 363
Author(s):  
Jieun Kim ◽  
La-Hee Park ◽  
Jeong-Myeong Ha ◽  
Eun Duck Park
Keyword(s):  
Electron Microscopy ◽  
High Temperatures ◽  
Oxidative Coupling ◽  
Exothermic Reaction ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
Oxidative Coupling Of Methane ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Adsorption Desorption

The oxidative coupling of methane (OCM) is operated at high temperatures and is a highly exothermic reaction; thus, hotspots form on the catalyst surface during reaction unless the produced heat is removed. It is crucial to control the heat formed because surface hotspots can degrade catalytic performance. Herein, we report the preparation of Mn2O3-Na2WO4/SiC catalysts using SiC, which has high thermal conductivity and good stability at high temperatures, and the catalyst was applied to the OCM. Two Mn2O3-Na2WO4/SiC catalysts were prepared by wet-impregnation on SiC supports having different particle sizes. For comparison, the Mn2O3-Na2WO4/SiO2 catalyst was also prepared by the same method. The catalysts were analyzed by nitrogen adsorption–desorption, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The transformation of SiC into α-cristobalite was observed for the Mn2O3-Na2WO4/SiC catalysts. Because SiC was completely converted into α-cristobalite for the nano-sized SiC-supported Mn2O3-Na2WO4 catalyst, the catalytic performance for the OCM reaction of Mn2O3-Na2WO4/n-SiC was similar to that of Mn2O3-Na2WO4/SiO2. However, only the surface layer of SiC was transformed into α-cristobalite for the micro-sized SiC (m-SiC) in Mn2O3-Na2WO4/m-SiC, resulting in a SiC@α-cristobalite core–shell structure. The Mn2O3-Na2WO4/m-SiC showed higher methane conversion and C2+ yield at 800 and 850 °C than Mn2O3-Na2WO4/SiO2.

scholarly journals SYNTHESIS AND ELECTROCHEMICAL PROPERTIES OF MESOPOROUS CARBON SUPPORTED WELL–DISPERSED COBALT OXIDES NANOPARTICLES

2018 ◽  
Vol 55 (1B) ◽  
pp. 230
Author(s):  
Nguyen Van Tu
Keyword(s):  
Electron Microscopy ◽  
Cobalt Oxide ◽  
Mesoporous Carbon ◽  
Good Control ◽  
Nitrogen Adsorption ◽  
Mesoporous Structure ◽  
Oxide Nanoparticles ◽  
Cobalt Oxide Nanoparticles ◽  
Transmission Electron ◽  
Adsorption Desorption

In this article, well–dispersed cobalt oxide nanoparticles supported on mesoporous carbon (CMK–3) have been successfully synthesized. The composites were characterized by field emission scanning electron microscopy, transmission electron microscopy, X–ray diffraction and nitrogen adsorption–desorption analysis. The results have confirmed that, at a cobalt loading of 15 wt%, the composites have not only retained mesoporous structure of the support but also shown a good control of dispersed cobalt oxide nanoparticles with size of ~4 nm. The electrochemical property tests for the synthesized samples have shown significant improvement compared to the blank carbon (CMK–3) without cobalt oxide incorporation.

The Photocatalysis Properties of Heterostructured WO3-TiO2 Composite Prepared by Waste WC-TiC Hardmetal

2013 ◽  
Vol 873 ◽  
pp. 603-611
Author(s):  
Yi Long Yang ◽  
Jin Shu Wang ◽  
Yong Li Li ◽  
Jun Shu Wu ◽  
Hong Yi Li
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Critical Role ◽  
Nitrogen Adsorption ◽  
Light Illumination ◽  
Hydrothermal Route ◽  
Transmission Electron ◽  
Facile Hydrothermal Route ◽  
Vis Spectroscopy ◽  
Adsorption Desorption

We reported a facile hydrothermal route for the preparation of WO3TiO2 composite nanoparticles (TWCNs) using waste WC-TiC hardmetal in the presence of hydrofluoric acid (HF). Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and nitrogen adsorption/desorption analysis were employed for structural and composition analyses of the TWCNs. Our results suggested that HF was not only strongly involved in the growth of WO3, but also played a critical role in the etching effect for TWCN product. The photocatalytic activity of TWCNs was investigated by UV-vis spectroscopy. Dye molecules could be rapidly decomposed with TWCNs photocatalyst under visible light illumination. The enhanced photocatalytic activity is attributed to well matched band edge positions of WO3 and TiO2, and the large specific surface area of TWCNs in view of the incorporation of mesopores. The results presented here are expected to make a contribution toward the development of recycling waste resource delicately for photocatalytic water purification.

scholarly journals Photocatalytic properties of Ru-doped titania prepared by homogeneous hydrolysis

2009 ◽  
Vol 7 (2) ◽  
pp. 259-266 ◽  
Author(s):  
Vendula Houšková ◽  
Václav Štengl ◽  
Snejana Bakardjieva ◽  
Nataliya Murafa ◽  
Václav Tyrpekl
Keyword(s):  
Electron Microscopy ◽  
Ruthenium Oxide ◽  
Nitrogen Adsorption ◽  
Photocatalytic Decomposition ◽  
X Ray Diffraction ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Doped Titania ◽  
Adsorption Desorption ◽  
Hydrolysis Of

AbstractNanocrystalline titania particles doped with ruthenium oxide have been prepared by the homogenous hydrolysis of TiOSO4 in aqueous solutions in the presence of urea. The synthesized particles were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), High Resolution Transmission Electron Microscopy (HRTEM), Selected Area Electron Diffraction (SAED) and Nitrogen adsorption-desorption was used for surface area (BET) and porosity determination (BJH). The photocatalytic activity of the Ru-doped titania samples were determined by photocatalytic decomposition of Orange II dye in an aqueous slurry during irradiation at 365 nm and 400 nm wavelengths.

scholarly journals Sonochemical Synthesis, Characterization, and Photocatalytic Activity of N-Doped TiO2Nanocrystals with Mesoporous Structure

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Tiekun Jia ◽  
Fang Fu ◽  
Junwei Zhao ◽  
Jian Chen ◽  
Xiaofeng Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Region ◽  
Nitrogen Adsorption ◽  
Mesoporous Structure ◽  
Diffuse Reflection Spectroscopy ◽  
X Ray ◽  
Transmission Electron ◽  
Average Size ◽  
Adsorption Desorption

N-Doped TiO2nanocrystals were synthesized via a simple sonochemical route, using titanium tetrachloride, aqueous ammonia, and urea as starting materials. The as-synthesized samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) equipped with an energy dispersion X-ray spectrometer (EDS), transmission electron microscopy (TEM), UV-vis diffuse reflection spectroscopy, Raman spectroscopy, and nitrogen adsorption-desorption isotherms. The results of TEM and nitrogen adsorption-desorption showed that the average size and specific surface area of the as-synthesized nanocrystals are 10 nm and 107.2 m2/g, respectively. Raman spectral characterization combined with the results of XRD and EDS revealed that N dopant ions were successfully doped into TiO2. Compared with pure TiO2, the adsorption band edge of N-doped TiO2samples exhibited an obvious red shift to visible region. The photocatalytic activities were evaluated by the degradation of Rhodamine B (RhB) under visible light, and the results showed that the N-doped TiO2sample synthesized by an optimal amount of urea exhibited excellent photocatalytic activity due to its special mesoporous structure and the incorporation of nitrogen dopant ions.

Heterogenization of manganese porphyrin via hydrogen bond in zeolite imidazolate framework-8 matrix, a host–guest interaction, as catalytic system for olefin epoxidation

2018 ◽  
Vol 22 (11) ◽  
pp. 972-980 ◽  
Author(s):  
Mojtaba Bagherzadeh ◽  
Elnaz Mesbahi
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Bond ◽  
Catalytic System ◽  
Nitrogen Adsorption ◽  
Olefin Epoxidation ◽  
Manganese Porphyrin ◽  
Transmission Electron ◽  
Classical Hydrogen Bond ◽  
Ft Ir ◽  
Adsorption Desorption

A heterogenized meso-tetrakis(2,3-dihydroxyphenyl)porphyrinatomanganese(III) acetate at zeolite imidazolate framework-8 (T(2,3-OHP)PorMn@ZIF-8) is investigated for the catalytic olefin epoxidation reactions at room temperature. Heterogenization is accomplished through a non-classical hydrogen bond proposed between T(2,3-OHP)PorMn bearing O–H groups and C–H of the 2-methylimidazolate linkers in the ZIF-8 structure. The aforementioned compound is characterized by X-ray powder diffraction (XRD), atomic absorption spectroscopy (AAS), nitrogen adsorption−desorption, FT-IR spectroscopy, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The catalytic system with rather high potential of reusability is proposed as a fairly efficient epoxidation catalyst compared to reports in homogeneous media.

Synthesis of Flower-Like Mesoporous γ-AlOOH and γ-Al2O3 Nanoarchitectures via an Ionic Liquid-Assisted Hydrothermal Route

NANO ◽  
2019 ◽  
Vol 14 (04) ◽  
pp. 1950046
Author(s):  
Tong Il Kim ◽  
Hak Sung Yun ◽  
Yung Jon ◽  
Gwang Bok Han ◽  
Sung Il Chae ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Ionic Liquid ◽  
Hydrothermal Reaction ◽  
Hydrothermal Process ◽  
Reaction System ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Transmission Electron ◽  
Adsorption Desorption

In this work, flower-like [Formula: see text]-AlOOH and [Formula: see text]-Al2O3 nanoarchitectures with excellent surface and mesoporous properties were successfully synthesized in ionic liquid-assisted hydrothermal reaction system. The as-prepared suprastructures were characterized by several techniques, such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen adsorption/desorption measurement. The formation mechanism of flower-like [Formula: see text]-AlOOH mesoporous crystallites by ionic liquid-assisted hydrothermal process was proposed and discussed. Flower-like [Formula: see text]-Al2O3 nanostructures were obtained by calcining the as-prepared [Formula: see text]-AlOOH at 600∘C for 2[Formula: see text]h, preserving the same morphology.

Synthesis and Characterization of Magnetic Nanocomposite Fe3O4@nSiO2@mSiO2 with Dual Shells Containing Non-Porous Silica and Mesoporous Silica Structure

2014 ◽  
Vol 926-930 ◽  
pp. 308-311
Author(s):  
Qian Yu ◽  
Jing Jing Sang ◽  
Ai Ping Fu ◽  
Hong Liang Li
Keyword(s):  
Electron Microscopy ◽  
Mesoporous Silica ◽  
Magnetic Measurements ◽  
Sol Gel ◽  
Porous Silica ◽  
Nitrogen Adsorption ◽  
Magnetic Core ◽  
Magnetic Nanocomposites ◽  
Transmission Electron ◽  
Adsorption Desorption

Magnetic nanocomposites of Fe3O4@nSiO2@mSiO2 were synthesized by a two-step template method. Firstly, Fe3O4 magnetic core encapsulated clusters of SiO2 nanoparticles (Fe3O4@nSiO2, non-porous SiO2) was prepared by a spray drying method. Then the core-shell spheres of Fe3O4@nSiO2 were coated further with an m-SiO2 layer (mesoporous silica) by a sol-gel process using CTAB as a template. The resultant samples were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Nitrogen adsorption-desorption and Magnetic measurements. The acquired magnetic nanocomposites possess abundant mesopores, thus extends their potential application in biomedical and wastewater treatment due to their magnetic separation ability upon an external magnetic field.

Synthesis of Nano-Structured Ni-Co-Al Hydrotalcites and Derived Mixed Oxides

2012 ◽  
Vol 626 ◽  
pp. 173-177 ◽  
Author(s):  
M. Abdus Salam ◽  
Ye Lwin ◽  
Suriati Sufian
Keyword(s):  
Electron Microscopy ◽  
Mixed Oxides ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Pore Networks ◽  
Nickel Cobalt ◽  
Transmission Electron ◽  
Adsorption Desorption ◽  
Synthesized Materials ◽  
Fft Analysis

nanostructured hydrotalcite-like compounds that contain nickel, cobalt and aluminum have been synthesized by conventional coprecipitation method without using any surfactants or templating agents. The structure and morphology of the coprecipitated nanohydrotalcites and its derived mixed oxides were characterized by powder X-ray diffraction (XRD), Fourier-transformed Infrared (FTIR) spectroscopy, field-emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), and nitrogen adsorption-desorption techniques. The results show that the synthesized materials exhibited micro-meso-pore networks. The cobalt-rich calcined hydrotalcites are generally amorphous, having a coral-like morphology whereas nickel-rich hydrotalcites show hexagonal plate-like morphology. The presence of nickel in mixed oxides catalyzed the reduction of Co-Al-O spinels. The Fast Fourier Transform (FFT) analysis of HRTEM revealed the inter planner distances of the crystal of hydrotalcite.

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