Hard-Templating Synthesis of Mesopours La1-xSrxMnO3+σ Perovskite and Catalysis Activity in CO Oxidation

2011 ◽  
Vol 306-307 ◽  
pp. 1342-1349 ◽  
Author(s):  
Xue Hui Huang ◽  
Ming Li
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
Surface Area ◽  
Sol Gel ◽  
Oxidation Of Co ◽  
X Ray ◽  
Adsorption Desorption ◽  
Templating Synthesis ◽  
Scanning Electron ◽  
Hard Templating

La1-xSrxMnO3+σperovskite/ySBA-15(x=0, 0.1, 0.2, 0.3、y=0, 1, 2, 3) catalyzers were prepared by two different methods, which are the hard-templating and sol-gel methods. The catalysts were characterized by Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy(SEM), energy-dispersive spectroscopy(EDS), X-ray fluorescence spectroscopy(XRD) and N2adsorption/desorption(BET). Their catalytic activity in the oxidation of CO was evaluated. BET and SEM results showed that the repeated template samples had higher surface area(143.7m2/g) and smaller particle size(18nm). The catalytic activity for CO reached the highest value when x=0.2 and y=2. The repeated template samples had higher activity than the sol-gel samples due to the higher surface area.

scholarly journals Combining Soft- and Hard-Templating Approaches in MWW-Type Zeolites

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3335
Author(s):  
Anderson Joel Schwanke ◽  
Jaíne Fernandes Gomes ◽  
Katia Bernardo-Gusmão ◽  
Sibele Pergher
Keyword(s):  
Electron Microscopy ◽  
X Ray Diffraction ◽  
N2 Adsorption ◽  
X Ray ◽  
Carbon Particles ◽  
Soft Templating ◽  
Small Crystallite ◽  
Scanning Electron ◽  
Soft Templates ◽  
Hard Templating

A combination of hard-templating (HT) and soft-templating (ST) approaches was studied to obtain MWW-type materials with intermediate physicochemical properties. The HT methodology involved the introduction of carbon particles as hard templates during gel synthesis to obtain a layered zeolitic precursor (LZP) with particles possessing a microspherical morphology. The LZP obtained was treated with surfactants as soft templates to expand the layers of the LZP, followed by a pillaring procedure. The materials were characterized by X-ray diffraction, transmission and scanning electron microscopy, elemental analysis and N2 adsorption. The results demonstrate that the obtained material possesses intermediate properties from both approaches, with interparticle mesopores/macropores and pore sizes between 18 and 46 Å. However, the ST procedure causes a partial disruption of some microspheres, forming small crystallite aggregates, and results in a decrease in the number of interparticle mesopores/macropores previously formed by the HT method.

scholarly journals Structural and optical properties of SnO2–Al2O3 nanocomposite synthesized via sol-gel route

2015 ◽  
Vol 33 (4) ◽  
pp. 714-718 ◽  
Author(s):  
Neeraj K. Mishra ◽  
Chaitnaya Kumar ◽  
Amit Kumar ◽  
Manish Kumar ◽  
Pratibha Chaudhary ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Properties ◽  
Sol Gel ◽  
Physical Interaction ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
X Ray ◽  
Sensing Applications ◽  
Scanning Electron

AbstractA nanocomposite of 0.5SnO2–0.5Al2O3 has been synthesized using a sol-gel route. Structural and optical properties of the nanocomposite have been discussed in detail. Powder X-ray diffraction and scanning electron microscopy with energy-dispersive X-ray diffraction spectroscopy confirm the phase purity and the particle size of the 0.5SnO2–0.5Al2O3 nanocomposite (13 to 15 nm). The scanning electron microscopy also confirms the porosity in the sample, useful in sensing applications. The FT-IR analysis confirms the presence of physical interaction between SnO2 and Al2O3 due to the slight shifting and broadening of characteristic bands. The UV-Vis analysis confirms the semiconducting nature because of direct transition of electrons into the 0.5SnO2–0.5Al2O3 nanocomposites.

Preparation of Borosilicate Xerogel and Research on its Mineralization

2012 ◽  
Vol 476-478 ◽  
pp. 2059-2062
Author(s):  
Chen Wang ◽  
Ya Dong Li ◽  
Gu Qiao Ding
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Ph Value ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compositional Changes ◽  
Scanning Electron

Tributyl borate was first adopted for the introduction of boron in the preparation of bioactive borosilicate xerogel by sol-gel method. The xerogel reacted continuously in 0.25M K2HPO4 solution with a starting pH value of 7.0 at 37 °C for 1day. The structural, morphologies and compositional changes resulting from the conversion were characterized using X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. The results indicated that speed of formation of HA was cut way back on the time with the addition of boron and the induction period for the HA nucleation on the surface of the borosilicate xerogel was short than 1 days. The conversion mechanism of the borosilicate xerogels to hydroxyapaptite was also discussed.

Synthesis of Nanosized HMS Mesoporous Molecular Sieve in an Ionic Liquid-Water Mixture

2011 ◽  
Vol 236-238 ◽  
pp. 2110-2113
Author(s):  
Hong Liu ◽  
Meng Yang Wang ◽  
Wei Ran Cao
Keyword(s):  
Electron Microscopy ◽  
Ionic Liquid ◽  
Sol Gel ◽  
Mesoporous Molecular Sieve ◽  
Nano Particles ◽  
Water Mixture ◽  
X Ray ◽  
Transmission Electron ◽  
Adsorption Desorption ◽  
Synthesized Materials

The hexagonal mesoporous silica (HMS) nano-particles were prepared in mixture of 1-butyl-3-methyl-imidazolium tetrafluoroborate (BMIM+BF4-) ionic liquid and water by a sol-gel method. The structure and morphology of obtained materials were characterized by X-ray powder diffraction (XRD), N2adsorption-desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and dynamic light scattering (DLS). The influence of the amount of BMIM+BF4-was investigated. It was shown that the synthesized materials have discrete and uniform spherical morphology with the size in the range of 68-177 nm (obtained from DLS measurements), and the particle size of HMS can be controlled by varying the amount of BMIM+BF4-.

scholarly journals Synthesis of Brushite from Phophogypsum Industrial Waste

2021 ◽  
Vol 12 (5) ◽  
pp. 6580-6588
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Industrial Waste ◽  
Sol Gel ◽  
Dicalcium Phosphate Dihydrate ◽  
X Ray Diffraction ◽  
Characterization Methods ◽  
X Ray ◽  
Phosphate Dihydrate ◽  
Scanning Electron

Dicalcium phosphate dihydrate (DCPD) nanoparticles, also known as brushite, are considered an important bioceramic compound. In this study, brushite was prepared from Moroccan phosphogypsum (PG) using a new sol-gel method. A two-step technique undergoes the synthesis of brushite, the preparation of anhydrite from PG followed by adding phosphoric acid in the presence of sodium hydroxide. The morphology, the chemical composition, and the crystallites size were obtained using Scanning Electron Microscopy (SEM-EDAX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR), respectively. According to the Debye-Scherrer equation, these characterization methods indicated that the synthesized brushite was highly pure according to the Ca/P ratio of 1.14 and an average crystallites size estimated at 66 nm. These results proved that the brushite was successfully synthesized from Moroccan phosphogypsum.

scholarly journals Facile Preparation of g-C3N4-WO3 Composite Gas Sensing Materials with Enhanced Gas Sensing Selectivity to Acetone

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Xiangfeng Chu ◽  
Junsong Liu ◽  
Shiming Liang ◽  
Linshan Bai ◽  
Yongping Dong ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Gas Sensing ◽  
Hydrothermal Processing ◽  
Optimum Temperature ◽  
X Ray ◽  
Gas Sensing Properties ◽  
Facile Preparation ◽  
Adsorption Desorption ◽  
Scanning Electron

In this paper, g-C3N4-WO3 composite materials were prepared by hydrothermal processing. The composites were characterized by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and N2 adsorption-desorption, respectively. The gas sensing properties of the composites were investigated. The results indicated that the addition of appropriate amount of g-C3N4 to WO3 could improve the response and selectivity to acetone. The sensor based on 2 wt% g-C3N4-WO3 composite showed the best gas sensing performances. When operating at optimum temperature of 310°C, the responses to 1000 ppm and 0.5 ppm acetone were 58.2 and 1.6, respectively, and the ratio of the S1000 ppm acetone to S1000 ppm ethanol reached 3.7.

Characterization of Titanium Dioxide Nanopowder Synthesized by Sol Gel Grinding Method

2012 ◽  
Vol 626 ◽  
pp. 425-429 ◽  
Author(s):  
N.N. Hafizah ◽  
Mohamed Zahidi Musa ◽  
Mohamad Hafiz Mamat ◽  
M. Rusop
Keyword(s):  
Electron Microscopy ◽  
Anatase Phase ◽  
Sol Gel ◽  
Precursor Concentration ◽  
X Ray Diffraction ◽  
X Ray ◽  
Grinding Method ◽  
Fesem Micrographs ◽  
Scanning Electron

In this study, TiO2nanopowder was synthesized via a sol-gel grinding method. The effects of TiO2precursor concentration of TiO2nanopowder were investigated. The TiO2nanopowder obtained were characterized using X-ray diffraction (XRD), Raman spectroscopy and field emission scanning electron microscopy (FESEM) for their structural properties. From the calculation of the crystallite size in XRD, the size of the nanoparticles obtained is 49.55 nm at the highest TiO2precursor concentration. In contrast, at the lower concentration of 0.4 molar give the cryatallite size of 12.84 nm. Further, XRD and Raman spectrum results confirmed the TiO2nanopowder obtain composed of only anatase phase. The FESEM micrographs of TiO2nanopowder also were discussed in this paper.

VISIBLE LIGHT ACTIVE Cu2+/TiO2 NANOCATALYST FOR DEGRADATION OF DICHLORVOS

2012 ◽  
Vol 11 (05) ◽  
pp. 1250030 ◽  
Author(s):  
TESHOME ABDO SEGNE ◽  
SIVA RAO TIRUKKOVALLURI ◽  
SUBRAHMANYAM CHALLAPALLI
Keyword(s):  
Catalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Light Illumination ◽  
X Ray ◽  
Photo Catalytic Activity ◽  
Visible Light Active ◽  
Adsorption Desorption

The advantage of doping of TiO2 with copper has been utilized for enhanced degradation of pesticide under visible light irradiation. The sol–gel method has been undertaken for the synthesis of copper-doped TiO2 by varying the dopant loadings from 0.25 wt.% to 1.0 wt.% of Cu2+ . The doped samples were characterized by UV-Visible Diffuse Reflectance Spectroscopy (DRS), N2 adsorption–desorption (BET), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), and Energy Dispersive Spectrometry (EDS). The photocatalytic activity of the catalyst was tested by degradation of dichlorvos under visible light illumination. The results found that 0.75 wt.% of Cu2+ doped nanocatalysts have better photo catalytic activity than the rest of percentages doped, undoped TiO2 and Degussa P25. The reduction of band gap was estimated and the influence of the process parameters on photo catalytic activity of the catalyst has been explained.

Synthesis and Thermal Stability of Nontransformable Tetragonal (ZrO2)0.96(REO1.5)0.04 (Re=Sc3+, Y3+) Nanocrystals

2013 ◽  
Vol 334-335 ◽  
pp. 60-64 ◽  
Author(s):  
Mohammad Reza Loghman-Estark ◽  
Reza Shoja Razavi ◽  
Hossein Edris
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Sol Gel ◽  
Average Diameter ◽  
X Ray ◽  
Transmission Electron ◽  
20 Nm ◽  
Thermal Stability Of ◽  
Scanning Electron

Scandia, yttria doped zirconia ((ZrO2)0.96(REO1.5)0.04(RE=Sc3+, Y3+)) nanoparticles were prepared by the modified sol-gel method. The microstructure of the products was characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. Thermal stabillity of SYSZ nanocrystals were also investigated. The SYSZ nanocrystals synthesized with EGM:Zr+4mole ratio 4:1, calcined at 700°C, have average diameter of ~20 nm.

Biomorphic SiC Prepared from Carbonized Millet by Sol-Gel and Carbothermal Reduction Processing

2010 ◽  
Vol 152-153 ◽  
pp. 1683-1686
Author(s):  
Qing Wang ◽  
Ya Hui Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silicon Carbide ◽  
Phase Composition ◽  
Carbothermal Reduction ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbon Template ◽  
Scanning Electron

Biomorphic silicon carbide (bioSiC) was prepared by high temperature pyrolysis and sol-gel and carbothermal reduction processing at 1600 oC. The morphology and microstructure of carbon-silica composites and purified bioSiC samples were characterized by scanning electron microscopy. The phase composition of the resulting sample was analyzed by X-ray diffraction. The results suggest that the bioSiC mainly consists of cubic ß-SiC, and principally replicates the shape and microstructure of the carbon template.

Sign in / Sign up

Export Citation Format

Share Document