HRTEM Study of nano-TiO2 Powder

2008 ◽  
Vol 59 (4) ◽  
Author(s):  
Ionela Carazeanu Popovici ◽  
Mihai Girtu ◽  
Elisabeta Chirila ◽  
Victor Ciupina ◽  
Gabriel Prodan
Keyword(s):  
Electron Microscopy ◽  
Anatase Phase ◽  
Thermal Hydrolysis ◽  
Tio2 Powder ◽  
X Ray Diffraction ◽  
Nano Tio2 ◽  
X Ray ◽  
Transmission Electron ◽  
Hydrolysis Of ◽  
Photovoltaic Material

Titanium dioxide (TiO2) has been one of the most attractive photo electrochemical and photovoltaic material during the last decades due to its scientific and technological importance. The TiO2 powder was synthesized by thermal hydrolysis of TiCl4. The crystalline structures and morphologies of the powder have been characterized by high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). The crystals dimensions varied from 15 nm to 23 nm and it have been established that the studied nanopowder is stable in the anatase phase.

Shape-Controlled Synthesis of Gadolinium Oxide Nanostructure via Facile Process

2012 ◽  
Vol 182-183 ◽  
pp. 265-269
Author(s):  
Qing Zhang ◽  
Pei Wen Hao ◽  
Xin Qu ◽  
Chun Wang ◽  
Rui Xia Li
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Process ◽  
X Ray Diffraction ◽  
Hydrothermal Temperature ◽  
X Ray ◽  
Transmission Electron ◽  
Heating Treatment ◽  
Shape Controlled ◽  
Low Dimensional ◽  
Hydrolysis Of

A facile method to selectively synthesize nano-scaled Gd2O3 with different morphology such as nanosheres and nanorods has been developed in our report. The precursors GdOHCO3 can be prepared by a two-step hydrothermal process via homogeneous generation of hydroxide ions through the hydrolysis of urea, and the formation of different morphology structures were obtained under different reaction temperatures. After further heating treatment, a transformation from GdOHCO3 to cubic Gd2O3 takes place. The morphology and size of nano Gd2O3 strongly depend on that of the precursors GdOHCO3. The X-ray diffraction, transmission electron microscopy and scanning electron microscopy were employed to characterize the as-obtained low-dimensional nanostructures. And the effects of hydrothermal temperature, solvent and urea concentration on the morphologies of the products were also studied.

Authigenic palygorskite in Miocene sediments in Linxia basin, Gansu, northwestern China

Clay Minerals ◽  
2007 ◽  
Vol 42 (1) ◽  
pp. 45-58 ◽  
Author(s):  
H. L. Hong ◽  
N. Yu ◽  
P. Xiao ◽  
Y. H. Zhu ◽  
K. X. Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Clay Mineral ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineral Particles ◽  
Transmission Electron ◽  
Mineralogical Characteristics ◽  
Linxia Basin ◽  
Hydrolysis Of ◽  
Scanning Electron

AbstractThe mineralogical characteristics of authigenic palygorskite occurring with chlorite and illite in Miocene sediments in Linxia basin were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM). The XRD results suggest that the mineral composition of the sediments includes mainly quartz, chlorite, illite, calcite, plagioclase, orthoclase, minor palygorskite and small amounts of gypsum and ankerite. Two kinds of palygorskite were observed in the sediments, relatively straight fibrous particles found in matted, felted masses associated with platy chlorite and silky aggregates found in the void spaces. The former probably replaces chlorite grains, growing from the edges or the fissures of chlorite particles. Chlorite grains exhibit bay-shaped or rounded edges, with ambiguous felted boundaries between chlorite particles, indicative of an intensive dissolution process and the growth of palygorskite at the expense of chlorite. Palygorskite is also observed as inclusions within calcite, sprouting from or coating calcite surfaces, suggesting that palygorskite crystallized from solution. The textural relations of palygorskite and the occurrence of ankerite and the characteristically Fe-bearing palygorskite in the sediments suggest the destruction and hydrolysis of chlorite. The ankerite seems to be preferentially present in the void spaces, closely associated with chlorite and illite; fibrous palygorskite crystallizes at the edges of these clay mineral particles and the platy clay mineral particles are gradually replaced by fibrous palygorskite crystals, suggesting that alteration of chlorite to palygorskite involves an interaction with water during the diagenetic process.

Facile Enrichment and Photocatalytical Degradation of Low Concentration MB in Aqueous Solution

2011 ◽  
Vol 110-116 ◽  
pp. 2308-2315
Author(s):  
Liu Xue Zhang ◽  
Xiu Lian Wang
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Fine Particles ◽  
X Ray Diffraction ◽  
High Concentration ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Low Concentrations ◽  
Hydrolysis Of

Fine particles of photoactive anatase-type TiO2, prepared by hydrolysis of tetrabutyl orthotitanate and crystallized under microwave (MV) irradiation, were loaded on adsorbent support attapulgite (ATP). The prepared hybrids TiO2-ATP were characterized with transmission electron microscopy (TEM), selected-area electron diffraction (SAED), and X-ray diffraction (XRD) and photoactivity properties were evaluated separately. The substrates of target were adsorbed on the adsorbent support, and then a high concentration environments of the substrate was formed around the loaded TiO2, resulting in an increase in the photodestruction rate. One of the most interesting features of the resulting catalysts with low titania contain (<30%) is their fast decantability in comparison with that of TiO2. This way one of the most important drawbacks of photocatalysis, the catalysts separation from the solution, was overcome by simple sedimentation and decantation. The low concentrations MB may be removed through enrichment and photodegradation using the prepared TiO2-ATP photocatalyst.

Enhanced photodegradation activity of electrospun porous TiO2 fibers

2019 ◽  
Vol 12 (06) ◽  
pp. 1941002 ◽  
Author(s):  
Peng Zhao ◽  
Peipei Huo ◽  
Xinxu Han ◽  
Bo Liu
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Anatase Phase ◽  
Mesoporous Structure ◽  
High Specific Surface Area ◽  
X Ray Diffraction ◽  
Hollow Nanofibers ◽  
X Ray ◽  
Transmission Electron ◽  
Calcination Method

Mesoporous titanium dioxide (TiO2) hollow nanofibers (HNFs) were successfully prepared by a facile electrospinning and calcination method. Techniques such as X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were utilized to characterize TiO2 fibers. It was revealed that TiO2 crystals with an appropriate anatase fraction (71.58%) were grown and a tubular mesoporous structure was formed with a high specific surface area. Photodecomposition of methyl orange (MO) solution showed that TiO2 HNFs exhibited much higher photocatalytic activity than corresponding TiO2 nanofibers (NFs) and loose-structured nanofibers (LNFs). The significant enhancement of photocatalytic activity was attributed to both the sufficient growth of active anatase phase primarily and a tubular mesoporous nature of TiO2 HNFs.

Preparation of nanocrystalline titania powder via aerosol pyrolysis of titanium tetrabutoxide

1999 ◽  
Vol 14 (10) ◽  
pp. 3938-3948 ◽  
Author(s):  
P. P. Ahonen ◽  
E. I. Kauppinen ◽  
J. C. Joubert ◽  
J. L. Deschanvres ◽  
G. Van Tendeloo
Keyword(s):  
Electron Microscopy ◽  
Ultrafine Particles ◽  
Anatase Phase ◽  
Spherical Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Raman And Infrared Spectroscopy ◽  
Nanocrystalline Titanium ◽  
Titanium Tetrabutoxide

Nanocrystalline titanium dioxide was prepared via aerosol pyrolysis of titanium alkoxide precursor at 200–580 °C in air and in nitrogen atmospheres. Powders were characterized by x-ray diffraction, thermogravimetric analysis, Brunauer–Emmett–Teller analysis, scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, x-ray fluorescence, Raman and infrared spectroscopy, and Berner-type low-pressure impactor. The anatase phase transition was initiated at 500 °C in nitrogen and at 580 °C in air. Under other conditions amorphous powders were observed and transformed to nanocrystalline TiO2 via thermal postannealing. In air, smooth and spherical particles with 2–4-μm diameter were formed with an as-expected tendency to convert to rutile in the thermal postannealings. In nitrogen, a fraction of the titanium tetrabutoxide precursor evaporated and formed ultrafine particles via the gas-to-particle conversion. At 500 °C thermally stable anatase phase was formed in nitrogen. A specific surface area as high as 280 m2 g−1 was observed for an as-prepared powder.

scholarly journals The effect of sintering temperatures of TiO2(B)-nanotubes on its microstructure

2018 ◽  
Vol 50 (3) ◽  
pp. 291-298
Author(s):  
H. Sutrisno ◽  
E.D. Siswani ◽  
K.S. Budiasih
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Tio2 Nanotubes ◽  
Single Phase ◽  
Anatase Phase ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Xrd Patterns

Titanium dioxide (TiO2)-nanotubes were prepared by a simple technique reflux. The morphologies and microstructures of nanotubes were characterized by high resolution scanning electron microscopy (HRSEM), high resolution transmission electron microscopy (TEM), powder X-ray diffraction (XRD,) energy dispersive X-ray spectroscopy (EDS) and surface area analyzer. The microstructures of TiO2 phases obtained from the sintering process of TiO2-nanotubes for 1 hour at various temperatures from 100 to 1000?C at intervals of 50?C were investigated from the XRD diffractograms. The analyses of morphologies and microstructures from HRSEM and HRTEM images describe the sample as nanotubes. The nanotube is single phase exhibiting TiO2(B) structure. The XRD patterns show that TiO2(B)-nanotubes transform into anatase phase and then become rutile due to increasing sintering temperatures.

A Single-Step Synthesis of Rutile TiO2 Dendrite Crystal with Sonication

2011 ◽  
Vol 356-360 ◽  
pp. 399-402 ◽  
Author(s):  
Xi Kui Wang ◽  
Wei Lin Guo ◽  
Chen Wang
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Single Step ◽  
Sonochemical Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Crystallite Sizes ◽  
Crystalline Forms ◽  
Hydrolysis Of

A single-step sonochemical method to directly prepare rutile nanocrystal TiO2 has been developed. TiO2 nanaoparticles were synthesized by the hydrolysis of TiCl4 in the presence of water and ethanol under ultrasonic irradiationat 70 °C for 3 h. The crystalline forms and crystallite sizes of the produts were characterized by X-ray diffraction, transmission electron microscopy and thermogravimetry-differential thermal analysis. The TEM images showed the morphology of as-prapared TiO2 was pinnate in shape and the average sizes were ca. 4/12 nm (W/L). The columnar particles were linked together each other at the certain principle, forming the shape like dendrite crystal. The formation mechanism of the dendrite crystal nanocrystalline TiO2 was also discussed.

ON THE PHONON CONFINEMENT AND PARTICLE SIZE IN TiO2:ZnO NANOCOMPOSITE

2011 ◽  
Vol 10 (01n02) ◽  
pp. 227-231 ◽  
Author(s):  
S. S. KANMANI ◽  
N. RAJKUMAR ◽  
K. RAMACHANDRAN
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Chemical Method ◽  
Anatase Phase ◽  
Phonon Confinement ◽  
X Ray Diffraction ◽  
Raman Analysis ◽  
X Ray ◽  
Transmission Electron

TiO 2 nanoparticles and TiO 2: ZnO (80:20) nanocomposites were prepared by chemical method, and X-ray diffraction, high resolution transmission electron microscopy, and Raman analysis of the samples showed a strong anatase phase and they are further used to find and compare the particle size.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

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