Studies on (SBA-15)-AgI Host-Guest Nanocomposite Materials

2015 ◽  
Vol 723 ◽  
pp. 481-484
Author(s):  
Xiao Dong Li
Keyword(s):  
Molecular Sieve ◽  
Solid Phase ◽  
Nitrogen Adsorption ◽  
Nanocomposite Materials ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
Radiation Process ◽  
Thermal Diffusion Method ◽  
New Type ◽  
Adsorption Desorption

SBA-15 molecular sieve owned the characteristic of uniform nanoscale channels, large pores, thick walls and high hydrothermal stability. It has the potential foreground as adsorption, separation, catalysis and new type host-guest nanocomposite materials. In this paper, SBA-15 molecular sieve was synthesized in acidic medium by hydrothermal method using triblock copolymers (EG20PG40EG20) as template, tetraethoxysilane as silica resource. Semiconductor material AgI was incorporated into the mesoporous channels of the SBA-15 molecular sieve by solid phase thermal diffusion method and the (SBA-15)-AgI nanocomposites materials were prepared. The products were characterized by means of powder X-ray diffraction, low-temperature nitrogen adsorption-desorption technique at 77 K and luminous properties were studied. The results showed that AgI went into the channels of the SBA-15, the materials (SBA-15)-AgI remained the highly ordered two-dimensional hexagonal. However, the crystalline was decreased to some degree, the pore volume, pore size and the surface area decreased to some extent compared to those of the SBA-15 molecular sieve. It was found by luminous studies that the energy band gap of the (SBA-15) -AgI composite material is very high and radiation process is very strong. The composite materials possess very good luminous performance and can be hopefully acted as luminous materials.

Synthesis and Characterization of Mesoporous Molecular Sieve Al-MCM-41 Using Kaolin as Raw Material

2013 ◽  
Vol 779-780 ◽  
pp. 201-204
Author(s):  
Miao Li ◽  
Hong Wang ◽  
Xian Qing Li ◽  
Jin Rong Liu
Keyword(s):  
Molecular Sieve ◽  
Nitrogen Adsorption ◽  
Mesoporous Molecular Sieve ◽  
Raw Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Adsorption Desorption ◽  
Calcined Kaolin ◽  
Mcm 41

Ordered hexagonally mesoporous molecular sieve Al-MCM-41 with Si/Al (atom) ratio=9 was prepared by hydrothermal synthesis using raw kaolin. X-ray diffraction (XRD), Nitrogen adsorption desorption, Transmission Electron Microscope (TEM) and Energy Dispersive X-ray Detector (EDX) were employed to characterise raw kaolin, calcined kaolin, as-synthesized and calcined Al-MCM-41. The results indicated that characteristic reflections of raw kaolin disappeared after calcination, both of as-synthesized and calcined Al-MCM-41 exhibited well ordered hexagonally mesoporous molecular sieve structure.

Synthesis and Characterization of the Catalysts 5 wt.% and 10 wt.% Co/SBA-15

2010 ◽  
Vol 660-661 ◽  
pp. 561-566
Author(s):  
L.A. Lima ◽  
B.V. Sousa ◽  
Meiry Glaúcia Freire Rodrigues
Keyword(s):  
Ethylene Oxide ◽  
Molecular Sieve ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Poly Ethylene Oxide ◽  
Desorption Isotherms ◽  
Poly Ethylene ◽  
Adsorption Desorption

Catalysts supported on SBA-15 were obtained by wet impregnation using aqueous solution of cobalt nitrate, where different contents of cobalt (5 wt% and 10 wt%) were prepared. The molecular sieve SBA-15 was synthesized using tetra ethyl ortho silicate (TEOS) as silicate source, and triblock copolymer, poly-(ethylene oxide)-poly (propylene oxide)-poly-(ethylene oxide) PEO-PPO-PEO as the organic structure directing agent. These materials were characterized by X-ray diffraction (XRD), X-ray energy dispersion spectrophotometer (EDX) and Nitrogen adsorption–desorption isotherms (BET). The results from the XRD showed that the molecular sieve mesoporous (SBA-15) was identified by X-ray diffraction, especially from the (210) and (300) peaks, which represent a typical spectrum for the SBA-15. Characterization of catalysts by Nitrogen adsorption–desorption isotherms (BET) made it possible to verify the the samples had been of type IV with hysteresis of corresponding the H2 type the porous materials.

Preparation and Luminescence of Host-Guest (SBA-15)-(Arsenano-III) Nanocomposite Materials

2013 ◽  
Vol 785-786 ◽  
pp. 537-541
Author(s):  
Xiao Dong Li
Keyword(s):  
Low Temperature ◽  
Absorption Spectra ◽  
Molecular Sieves ◽  
Diffuse Reflectance ◽  
Nitrogen Adsorption ◽  
Nanocomposite Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Prepared Composite ◽  
Adsorption Desorption

The nanosized channels of SBA-15 molecular sieves were used as template and arsenano-III (ASA-III) was trapped inside the SBA-15 molecular sieves by means of liquid grafting method. The prepared nanocomposite materials were characterized by the powder X-ray diffraction, low temperature nitrogen adsorption-desorption and solid diffuse reflectance absorption spectra. The powder X-ray diffraction indicated the structure of the (SBA-15)-(ASA-III) still remains two-dimensional hexagonal mesostructrure. The low temperature nitrogen adsorption-desorption research showed that the ASA-III was present on the inner surface and partially occupied the channels of the molecular sieve. The UV-Vis solid state diffuse reflectance absorption spectra of the prepared composite materials showed the steroconfinmment effect of the host SBA-15 channels on the guest ASA-III and the guest was in the channels of the SBA-15 host. Luminous spectra showed that the prepared (SBA-15)-(ASA-III) nanocomposite materials have the investigating optical properties.

Preparation and Characterization of MCM-41 Mesoporous Silica Functionalized with Sulfonic Acid Groups

2013 ◽  
Vol 781-784 ◽  
pp. 215-218
Author(s):  
Xue Ding ◽  
Xi Chang Yu ◽  
Hai Xia Sun
Keyword(s):  
Molecular Sieve ◽  
Sulfonic Acid ◽  
Nitrogen Adsorption ◽  
Mesoporous Molecular Sieve ◽  
X Ray Diffraction ◽  
Sh Group ◽  
Temperature Programmed ◽  
Adsorption Desorption ◽  
Sulfonic Acid Groups ◽  
Mcm 41

Mesoporous molecular sieve MCM-41 was modified by using 3-mercaptopropyltriethoxysilane as a coupling agent and MCM-41 functionalized with sulfonic acid groups was prepared. The prepared product was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption technique and temperature programmed desorption. The results showed that during the process of modification the frameworks of the molecular sieve were not destroyed, the channel has ordered property. SH group was successfully grafted to the surface of channels of the molecular sieve. The acid amount on the mesoporous material functionalized with sulfonic acid groups reached 0.755mmol/g, showing a potential application foreground as a catalyst.

Application of raw and modified Uruguayan clays to phosphate adsorption for water remediation

MRS Advances ◽  
2018 ◽  
Vol 3 (61) ◽  
pp. 3543-3549
Author(s):  
Pablo González ◽  
Andrea C. De Los Santos ◽  
Jorge R. Castiglioni ◽  
María A. De León
Keyword(s):  
Nitrogen Adsorption ◽  
Pillared Clay ◽  
Water Remediation ◽  
Phosphate Adsorption ◽  
X Ray Diffraction ◽  
Order Model ◽  
Freundlich Model ◽  
X Ray ◽  
First Order ◽  
Adsorption Desorption

ABSTRACTA raw clay from Uruguay was modified with aluminium to obtain an aluminium pillared clay (Al-PILC). The solids were characterized by scanning electron microscopy, X-ray diffraction and nitrogen adsorption-desorption isotherms. The Al-PILC retained the typical laminar structure of montmorillonite. The specific surface area and the microporous volume of the Al-PILC, 235 m2 g-1 and 0.096 cm3 g-1, respectively, were much higher than those of the clay. The phosphate adsorption capacity of the Al-PILC was higher than those of the clay. The phosphate adsorption kinetic followed the pseudo-first-order model for both, the clay and the Al-PILC, and the phosphate adsorption isotherm for the Al-PILC fit the Freundlich model.

scholarly journals Highly Porous Carbon Materials Filled with Nickel Hydroxide Nanoparticles; Synthesis, Study, Application in Electrochemistry

2015 ◽  
Vol 17 (3) ◽  
pp. 187 ◽  
Author(s):  
Yu.A. Zakharov ◽  
A.N. Voropay ◽  
N.M. Fedorova ◽  
V.M. Pugachev ◽  
A.V. Puzynin ◽  
...  
Keyword(s):  
Porous Carbon ◽  
Nickel Hydroxide ◽  
Nitrogen Adsorption ◽  
Porous Carbon Material ◽  
X Ray Diffraction ◽  
Scanning Rate ◽  
Electrode Cell ◽  
Adsorption Desorption ◽  
Electrode Characteristics ◽  
Study Application

<p>Nickel hydroxide was deposited on the surface of the porous carbon to obtain a cathode material for supercapacitors. This work is the first part of the study of Ni(OH)<sub>2</sub>/С composite, which considers the conditions of its synthesis using two types of porous carbon matrices with a highly developed specific surface area (1000–3000 m<sup>2</sup>/g) and two types of precursors (NiCl<sub>2</sub>*6H<sub>2</sub>O and Ni(N<sub>3</sub>)<sub>2</sub>). The morphology of the systems, in particular the shape and size characteristics of the hydroxide filler particles, was examined using the scanning electron microscopy, X-ray diffraction, and nitrogen adsorption-desorption at 77 K. The measurements of capacity of the Ni(OH)<sub>2</sub>/С-electrodes were made in 6 M KOH using an asymmetric two-electrode cell (a porous carbon material with known electrode characteristics was employed as the counter electrode). The capacity was shown to decrease by 22–56% with increasing the scanning rate from 10 to 80 mV/s. A maximum capacity of the composite was obtained at a scanning rate of 10 mV/s was 346 F/g.</p>

Structural and surface aspects of thermally treated copper aluminium mixed hydroxides

1991 ◽  
Vol 69 (10) ◽  
pp. 1511-1515 ◽  
Author(s):  
Awad I. Ahmed ◽  
S. E. Samra ◽  
S. A. El-Hakam
Keyword(s):  
Pore Structure ◽  
Copper Content ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Phase Changes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Areas ◽  
Structure Surface ◽  
Adsorption Desorption

CuO–Al2O3 catalysts containing various amounts of copper oxide have been prepared by precipitation. The phase changes were studied by X-ray diffraction. The results obtained revealed that the thermal treatment of solid CuO–Al2O3 at 700 °C produced only crystalline CuO. Heating to 900 °C led to the formation of copper alumina spinel together with unreacted CuO and γ-Al2O3. The spinel content was found to increase with increasing copper content. Nitrogen adsorption–desorption isotherms on the calcined samples have been measured. Surface areas have been calculated and the pore structure analysed. The textural properties of the system were found to depend on both the copper content and the calcination temperature. Key words: CuO, Al2O3 catalysts, structure, surface area, pore structure.

Deciphering the Adsorption Behavior of Volatile Organic Compounds with Electrospun Polyacrylonitrile/Molecular Sieve Nanocomposites

2019 ◽  
Vol 19 (11) ◽  
pp. 7315-7319 ◽  
Author(s):  
Yi-Xin Wang ◽  
Hong Tao ◽  
Min-Nan Chen ◽  
Ling-Shao ◽  
Guang-Feng Shang ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Adsorption Capacity ◽  
Organic Compounds ◽  
Molecular Sieve ◽  
Fiber Surface ◽  
Polyacrylonitrile Fiber ◽  
Volatile Organic ◽  
New Type ◽  
Short Time ◽  
Adsorption Desorption

In this study, a new type of molecular sieve/polyacrylonitrile fiber (M-PAN) was prepared by electrospinning to adsorb atmospheric volatile organic compounds (VOCs). The suitable content of molecular sieve in nanocomposites was also determined for achieving maximum VOCs adsorption capacity. SEM, TEM and N2 adsorption/desorption analyzer were performed for characterization of the surface morphology, structural properties, surface area and pore size. A part of molecular sieve is exposed on the fiber surface where VOCs can be adsorbed efficiently in a short time. Acetone was used as a challenge pollutant to evaluate the adsorption of VOCs at different recycling times and types of electrospinning nanofibers. The adsorption capacity of 6M-PAN (60% weight of molecular sieve) nanofiber reached 58.2 μg g−1 and the reused nanofibers nearly had the same adsorption capacity as the newly prepared nanofibers after several times of recirculation.

scholarly journals Bulk Versus Surface Modification of Alumina with Mn and Ce Based Oxides for CH4 Catalytic Combustion

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1771 ◽  
Author(s):  
Stefan Neatu ◽  
Mihaela M. Trandafir ◽  
Adelina Stănoiu ◽  
Ovidiu G. Florea ◽  
Cristian E. Simion ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Combustion ◽  
Mixed Oxides ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Programmed ◽  
Catalytic Combustion Of Methane ◽  
Adsorption Desorption

This study presents the synthesis and characterization of lanthanum-modified alumina supported cerium–manganese mixed oxides, which were prepared by three different methods (coprecipitation, impregnation and citrate-based sol-gel method) followed by calcination at 500 °C. The physicochemical properties of the synthesized materials were investigated by various characterization techniques, namely: nitrogen adsorption-desorption isotherms, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and H2–temperature programmed reduction (TPR). This experimental study demonstrated that the role of the catalytic surface is much more important than the bulk one. Indeed, the incipient impregnation of CeO2–MnOx catalyst, supported on an optimized amount of 4 wt.% La2O3–Al2O3, provided the best results of the catalytic combustion of methane on our catalytic micro-convertors. This is mainly due to: (i) the highest pore size dimensions according to the Brunauer-Emmett-Teller (BET) investigations, (ii) the highest amount of Mn4+ or/and Ce4+ on the surface as revealed by XPS, (iii) the presence of a mixed phase (Ce2MnO6) as shown by X-ray diffraction; and (iv) a higher reducibility of Mn4+ or/and Ce4+ species as displayed by H2–TPR and therefore more reactive oxygen species.

Preparation of Porous Carbon and its Composite Materials via the Reaction under Autogenic Pressure at Elevated Temperature (RAPET)

2018 ◽  
Vol 921 ◽  
pp. 60-64
Author(s):  
Ke Xun Li ◽  
Jiang Jiang Ma ◽  
Jie Zhang ◽  
Kun Jia ◽  
Bi Cheng Zhou ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Composite Materials ◽  
Porous Carbon ◽  
Nitrogen Adsorption ◽  
Inorganic Materials ◽  
Bet Surface Area ◽  
Tetrabutyl Titanate ◽  
X Ray Diffraction ◽  
Discharge Performance ◽  
Adsorption Desorption

In this paper, we reported on the preparation of porous materials via a reaction under Autogenic Pressure at Elevated Temperature (RAPET) at 700°Cusing natural product and alkoxides as precursors. The RAPET is a new simple efficient method to prepare inorganic materials. The porous carbon and its composite materials were prepared via the method of RAPET using natural products such as sweet potato, coriander, the absorbent cotton and viscose fiber doped by tetrabutyl titanate (TBOT) and tetraethoxysilane (TEOS). The reaction temperature of RAPET was 700°C. The carbon and its composites were studied with scanning electron microscopy (SEM), X-ray diffraction (XRD) and nitrogen adsorption-desorption measurements. The BET surface area of the materials are different from 4m2/g to 405m2/g. The XRD investigation indicates that the phases of the TiO2 in the carbon/TiO2 composites are anatase. The materials show a certain charge-discharge performance.

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