Preparation and Characterization of TiO2 Nanoparticles / CNTs Composite Particles

2012 ◽  
Vol 268-270 ◽  
pp. 172-175
Author(s):  
Ming Qiu Wang ◽  
Jun Yan ◽  
Shi Guo Du ◽  
Bin Wang ◽  
Hao Qin
Keyword(s):  
Aqueous Solution ◽  
Surface Roughness ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Tetrabutyl Titanate ◽  
Composite Particles ◽  
Absorption Intensity ◽  
Main Material

By using tetrabutyl titanate as the main material, TiO2 nanoparticles / CNTs composite particles have been prepared in acidic abundant aqueous solution at low temperature without calcination. The microstructure of the composite particles, including surface morphology, phase composition and specific surface area was characterized by SEM, TEM, Raman, XPS and BET. The results reveal that TiO2 nanoparticles coated uniformly on CNTs surfaces were mainly anatase type. The surface roughness of CNTs was remarkably increased after coating. However, the specific surface area of composite particles decreased by 23.4 m2•g-1 than that of CNTs with uncoated TiO2. Photocatalytic activity of TiO2 nanoparticles / CNTs composite particles shows a significant increase of absorption intensity both in ultraviolet band and visible light band according to UV-vis spectra.

Characterization of Fluorinated Hβ Zeolite with NH4F

2010 ◽  
Vol 160-162 ◽  
pp. 524-528
Author(s):  
Zhen Tian ◽  
Nai Ci Bing
Keyword(s):  
Aqueous Solution ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Acid Sites ◽  
Total Acid ◽  
Hβ Zeolite ◽  
Surface Performance

Fluorination of the zeolite has been known as a useful method to modify its acidity and surface performance. In this paper, a set of zeolite Hβ were impregnated with aqueous solution of NH4F. The effects of NH4F impregnation on the structure and acidity of Hβ was investigated by XRD, BET measurements, NH3-TPD, and Py-IR. The change of specific surface area and pore volume of the fluorinated samples with NH4F can be attributed the reaction of NH4F with non-framework and framework aluminum. The fluorination increases the strength and changes the distribution of the acid sites; the fluorination also leads to the decrease of the total acid sites and the Brönsted acid sites due to the dealuminization of the samples and the substitution of the OH- by fluorine atoms.

scholarly journals Adsorption of Ammonium Nitrogen from Aqueous Solution on Chemically Activated Biochar Prepared from Sorghum Distillers Grain

2019 ◽  
Vol 9 (23) ◽  
pp. 5249 ◽  
Author(s):  
Derlin Hsu ◽  
Changyi Lu ◽  
Tairan Pang ◽  
Yuanpeng Wang ◽  
Guanhua Wang
Keyword(s):  
Aqueous Solution ◽  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Adsorption Process ◽  
Ammonium Nitrogen ◽  
Activated Biochar ◽  
Distillers Grain ◽  
Kinetics And Isotherms

Chemically activated biochars prepared from sorghum distillers grain using two base activators (NaOH and KOH) were investigated for their adsorption properties with respect to ammonium nitrogen from aqueous solution. Detailed characterizations, including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetry (TG), and specific surface area analyses, were carried out to offer a broad evaluation of the prepared biochars. The results showed that the NaOH- and KOH-activated biochars exhibited significantly enhanced adsorption capacity, by 2.93 and 4.74 times, respectively, in comparison with the pristine biochar. Although the NaOH-activated biochar possessed larger specific surface area (132.8 and 117.7 m2/g for the NaOH- and KOH-activated biochars, respectively), the KOH-activated biochar had higher adsorption capacity owing to its much higher content of functional groups. The adsorption kinetics and isotherms of the KOH-activated biochar at different temperatures were further studied. The biochar had a maximum adsorption capacity of 14.34 mg/g at 45 °C, which was satisfactory compared with other biochars prepared using different feedstocks. The adsorption process followed pseudo-second-order kinetics, and chemical adsorption was the rate-controlling step. The equilibrium data were consistent with the Freundlich isotherm, and the thermodynamic parameters suggested that the adsorption process was endothermic and spontaneous. Consequently, this work demonstrates that chemically activated biochar from sorghum distillers grain is effective for ammonium nitrogen removal.

Preparation and Characterization of the Typical Pt-NSR Catalyst

2011 ◽  
Vol 412 ◽  
pp. 365-369
Author(s):  
Yuan Feng Huang ◽  
Wei Jun Zhang ◽  
Li Shen ◽  
Jin Hu ◽  
Zhuo Heng Li ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Performance Testing ◽  
High Specific Surface Area ◽  
Impregnation Method ◽  
Temperature Programmed Reduction ◽  
Temperature Programmed ◽  
Co Precipitation

A series of Ba-Al-O NSR supports and Pt/Ba-Al-O NSR catalysts are prepared by co-precipitation and impregnation method in this work. The catalyst and the support are characterized by XRD, SEM, SBET performance testing. The structure and texture of the supports is observed and discussed. The results of SBET indicate that the supports possess relative high specific surface area (94~110 m2/g). Temperature programmed reduction is characterized by means of H2-TPR.

Mineralogical study of clays from Dobrodo, Serbia, for use in ceramics

Clay Minerals ◽  
2019 ◽  
Vol 54 (4) ◽  
pp. 369-377 ◽  
Author(s):  
Maja Milošević ◽  
Predrag Dabić ◽  
Sabina Kovač ◽  
Lazar Kaluđerović ◽  
Mihovil Logar
Keyword(s):  
Specific Surface ◽  
Cation Exchange ◽  
Surface Area ◽  
Specific Surface Area ◽  
Cation Exchange Capacity ◽  
Mineralogical Composition ◽  
Exchange Capacity ◽  
Mineralogical Characterization ◽  
Mineralogical Study

AbstractThis study focuses on the mineralogical characterization of four raw clay samples from Dobrodo deposit, Serbia. Several analytical methods were applied to determine the chemical and mineralogical composition, morphology and physical properties (colour, plasticity, specific surface area, particle size and cation-exchange capacity) of the clay samples. Kaolinite, smectite and illite are the predominant phases in all of the samples studied that contain between 60.2 and 87.1 wt.% of clay. Quartz, feldspars, paragonite and Ti- and Fe-bearing phases were also identified. The relatively high SiO2/Al2O3 mass ratio indicates abundant quartz. The cation-exchange capacity of the samples varied between low and moderately charged clay minerals (12–52 mmol 100 g–1) with specific surface area values ranging from 94 to 410 m2 g–1. The plasticity index values (11–23%) suggest low to moderate plasticity. Preliminary results show that most of the raw clay from Dobrodo deposit might be suitable for use in ceramic applications.

Fabrication and Characterization of Cu Doped CeO2 by Hydrothermal Process for Antimicrobial Activity

2019 ◽  
Vol 391 ◽  
pp. 114-119 ◽  
Author(s):  
Yeon Bin Choi ◽  
Jeong Hun Son ◽  
Dong Sik Bae
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Hydrothermal Process ◽  
Antibacterial Properties ◽  
Reaction Times ◽  
X Ray Diffraction ◽  
Spherical Type ◽  
Average Size

Cu doped CeO2 nanopowder was synthesized by hydrothermal process at 180°C for 2~10h. The average size and distribution of the synthesized Cu doped CeO2 nanopowder was controlled by reaction times. The crystallinity of the synthesized Cu doped CeO2 nanoparticles was investigated by X-ray diffraction (XRD). The morphology of the synthesized Cu doped CeO2 nanoparticles was observed by FE-SEM. The specific surface area of the synthesized Cu doped CeO2 nanoparticles was measured by BET. The crystal size of the synthesized Cu doped CeO2 nanoparticles decreased with decreasing reaction times. The average size of the synthesized Cu doped CeO2 nanoparticles was below 10nm and narrow, respectively. The shape of the synthesized Cu doped CeO2 nanoparticles was spherical type. The specific surface area of the synthesized Cu doped CeO2 nanoparticles increased with decreasing reaction times. Antibacterial properties of Cu doped CeO2 were analyzed by MIC method. The synthesized Cu doped CeO2 nanopowders showed antibacterial properties against E.coli and B.sub bacteria.

scholarly journals Measuring specific surface area of snow by near-infrared photography

2006 ◽  
Vol 52 (179) ◽  
pp. 558-564 ◽  
Author(s):  
Margret Matzl ◽  
Martin Schneebeli
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Near Infrared ◽  
Two Dimensions ◽  
Chemical Models ◽  
Snow Stratigraphy ◽  
Physical And Chemical

AbstractThe specific surface area (SSA) is considered an essential microstructural parameter for the characterization of snow. Photography in the near-infrared (NIR) spectrum is sensitive to the SSA. We calculated the snow reflectance from calibrated NIR images of snow-pit walls and measured the SSA of samples obtained at the same locations. This new method is used to map the snow stratigraphy. The correlation between reflectance and SSA was found to be 90%. Calibrated NIR photography allows quantitative determination of SSA and its spatial variation in a snow profile in two dimensions within an uncertainty of 15%. In an image covering 0.5–1.0 m2, even layers of 1mm thickness can be documented and measured. Spatial maps of SSA are an important tool in initializing and validating physical and chemical models of the snowpack.

Characterization of halloysite (North East Rif, Morocco): evaluation of its suitability for the ceramics industry

Clay Minerals ◽  
2018 ◽  
Vol 53 (1) ◽  
pp. 65-78 ◽  
Author(s):  
Abdelilah El Haddar ◽  
Elkhadir Gharibi ◽  
Ali Azdimousa ◽  
Nathalie Fagel ◽  
Iz-Eddine El Amrani El Hassani ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Fine Particles ◽  
High Plasticity ◽  
North East ◽  
Physico Chemical ◽  
Ceramics Industry ◽  
Tubular Crystals

ABSTRACTA halloysite clay from Nador (NE Morocco) was studied to evaluate its suitability in the ceramics industry. A cross-section involving all the Messinian facies was performed in the Melilla Neogene basin, at the foot of the Gourougou volcano, to establish the origin of the halloysite and estimate its reserves. White layers of halloysite and red clays rich in smectite occurring in contact with basal-reef limestone were characterized by mineralogical (XRD, IR), textural (SEM) and physico-chemical analyses (grain-size, Atterberg limits, DTA/TG, XRF and specific surface area). Ceramic properties were evaluated for halloysite fired from 500 to 1100°C to evaluate technical processing for ceramic production.The halloysite clay consists of fine particles with a high plasticity and a large specific surface area. The XRD investigation revealed the presence of 7 Å non-hydrated halloysite along with gibbsite, alunite, K-feldspar and traces of smectite and illite.The presence of halloysite was confirmed from the characteristic IR bands at 3695 and 3618 cm−1and the predominance of tubular crystals observed in the SEM. The chemical analysis revealed high contents linked to the presence of Al-rich phases (gibbsite and alunite). DTA/TG and XRD results of fired clay samples proved the dehydroxylation of halloysite and a rearrangement of metakaolinite to form mullite and spinel at 975°C.The Moroccan halloysite might be suitable for refractory ceramic applications. However, addition of quartz sand might be necessary to avoid crack development during firing and to reduce the plasticity of raw halloysite and minimize shrinkage during sintering.

Preparation and Characterization of Porous Yttrium Oxide Powders with High Specific Surface Area

2006 ◽  
Vol 24 (1) ◽  
pp. 34-38 ◽  
Author(s):  
Yongxiu Li ◽  
Xiaoyun Lin ◽  
Yizheng Wang ◽  
Junming Luo ◽  
Weili Sun
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Yttrium Oxide ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
Oxide Powders
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