Synthesis of Layered Titanate Micro/nano-materials for Efficient Pollutant Treatment in Aqueous Media

2011 ◽  
Vol 1309 ◽  
Author(s):  
Y. X. Tang ◽  
Y. K. Lai ◽  
D. G. Gong ◽  
Zhili Dong ◽  
Z. Chen
Keyword(s):  
Aqueous Media ◽  
Three Dimensional ◽  
High Specific Surface Area ◽  
Nano Materials ◽  
Raman Scattering Spectroscopy ◽  
Micro Particles ◽  
Transmission Electron ◽  
Composition And Structure ◽  
Layered Titanate ◽  
The One

ABSTRACTIn this work, the one dimensional (1D) titanate nanotubes (TNT)/nanowires (TNW), bulk titanate micro-particles (TMP), and three dimensional (3D) titanate microsphere particles (TMS) with high specific surface area were synthesized via different approaches. The chemical composition and structure of these products have been characterized by field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM) study and Raman scattering spectroscopy. The as-prepared TMS shows excellent adsorption performance compared with TMP, TNW and TNT when methylene blue (MB) and PbII ions are used as representative organic and inorganic pollutants.

Three-Dimensional Holey-Graphene Architectures for Highly Sensitive Enzymatic Electrochemical Determination of Hydrogen Peroxide

2019 ◽  
Vol 19 (11) ◽  
pp. 7404-7409 ◽  
Author(s):  
Aihua Jing ◽  
Gaofeng Liang ◽  
Hao Shi ◽  
Yixin Yuan ◽  
Quanxing Zhan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Peroxide ◽  
Graphene Oxide ◽  
Three Dimensional ◽  
Electrochemical Determination ◽  
High Specific Surface Area ◽  
3D Graphene ◽  
Practical Applications ◽  
Transmission Electron ◽  
Mild Defect

Three-dimensional (3D) graphene with high specific surface area, excellent conductivity and designed porosity is essential for many practical applications. Herein, holey graphene oxide with nano pores was facilely prepared via a convenient mild defect-etching reaction and then fabricated to 3D nanostructures via a reduction method. Based on the 3D architectures, a novel enzymatic hydrogen peroxide sensor was successfully fabricated. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were used to characterize the 3D holey graphene oxide architectures (3DHGO). Cyclic voltammetry (CV) was used to evaluate the electrochemical performance of 3DHGO at glassy carbon electrode (GCE). Excellent electrocatalytic activity to the reduction of H2O2 was observed, and a linear range of 5.0×10-8~5.0×10-5 M with a detection limit of 3.8×10-9 M was obtained. These results indicated that 3DHGO have potential as electrochemical biosensors.

Three-dimensional morphology of anatase nanocrystals obtained from supercritical flow synthesis with industrial grade TiOSO4 precursor

2019 ◽  
Vol 75 (6) ◽  
pp. 1086-1095 ◽  
Author(s):  
Jinlong Yu ◽  
Frederik Søndergaard-Pedersen ◽  
Aref Mamakhel ◽  
Paolo Lamagni ◽  
Bo Brummerstedt Iversen
Keyword(s):  
Three Dimensional ◽  
High Specific Surface Area ◽  
X Ray Diffraction ◽  
Titanyl Sulfate ◽  
Supercritical Flow ◽  
Price Expectation ◽  
X Ray ◽  
Industrial Grade ◽  
Transmission Electron ◽  
Dimensional Reconstruction

Anatase TiO2 (a-TiO2) nanocrystals are vital in catalytic applications both as catalysts (e.g. photodegradation) and as a carrier material (e.g. NOx removal from exhaust). The synthesis of a-TiO2 nanocrystals and their properties have been heavily scrutinized, but there exists a clear gap between the scientific literature, and the scale and price expectation of industrial application. Here it is demonstrated that the industrially most attractive Ti precursor, titanyl sulfate (TiOSO4), can be combined with the green, scalable and fast supercritical flow method to produce phase pure and highly crystalline a-TiO2 nanoparticles with high specific surface area. Control of the nanocrystal morphology is important since it is known that certain facets substantially promote catalytic activity. It is, however, in itself challenging to determine nanocrystal morphology to provide a rational basis for the synthesis control. Here we advocate the use of advanced Rietveld refinement of powder X-ray diffraction data including anisotropic size broadening models in aiding to establish the sample three-dimensional morphology. This relatively quick and robust method assists in overcoming the often encountered ambiguity inherent in two-dimensional to three-dimensional reconstruction of selected particle morphologies with transmission electron microscopy and tomography techniques.

Characterization of ultrathin Ge epilayers on (100) Si

1991 ◽  
Vol 69 (3-4) ◽  
pp. 246-254 ◽  
Author(s):  
J. -M. Baribeau ◽  
D. J. Lockwood ◽  
T. E. Jackman ◽  
P. Aebi ◽  
T. Tyliszczak ◽  
...  
Keyword(s):  
Strain Relaxation ◽  
Three Dimensional ◽  
Raman Scattering Spectroscopy ◽  
X Ray ◽  
Transmission Electron ◽  
Short Period ◽  
Short Period Superlattices ◽  
Direct Band ◽  
X Ray Absorption

The understanding of the epitaxy of pure Ge layers on Si is an important step towards the synthesis of SimGen (m, n < 10 monolayers) short-period superlattices. The possibility of a direct band-gap character makes these structures extremely attractive. We have grown thin buried Gen ([Formula: see text] monolayers) films on (100) Si by molecular beam epitaxy and studied their structural properties by a variety of techniques including Raman scattering spectroscopy, glancing incidence X-ray reflection, Rutherford backscattering, transmission electron microscopy, and extended X-ray absorption fine structure analysis. All these techniques allowed detection of the thin Ge layers and provided information about the thickness, morphology, strain distribution, and interface sharpness of these heterostructures. The Ge„ films with [Formula: see text] had a two-dimensional nature and showed no sign of strain relaxation. Intermixing at the Si–Ge interfaces was present in all these films and estimated to be not more than two monolayers. This smearing at the interfaces may have contributed to the maintenance of that pseudomorphicity. A thicker Ge layer (n = 12) showed evidence of strain relaxation and clustering in three-dimensional islands.

scholarly journals H3PW12O40 Anchored on the Three-Dimensional and Networked SBA-15 as an Efficient and Recyclable Catalyst for Mannich Reaction

2019 ◽  
Vol 64 (1) ◽  
Author(s):  
Tengfei Zhang ◽  
Wei Zhang ◽  
Hao Dong ◽  
Qing Liu
Keyword(s):  
Mannich Reaction ◽  
Three Dimensional ◽  
Impregnation Method ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
One Pot ◽  
Solvent Free Condition ◽  
Transmission Electron ◽  
Ft Ir ◽  
The One

Abstract. The three-dimensional and networked SBA-15 (3D-SBA-15) supported phosphotungstic acid (PW) was used as heterogeneous catalyst for the one-pot three-components Mannich reaction at room temperature. The H3PW12O40/3D-SBA-15 catalyst was prepared using an impregnation method and confirmed by series of characterizations such as Fourier-transform infrared spectra (FT-IR), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), N2 physisorption and thermogravimetric (TG) analysis. 50PW/3D-SBA-15 catalyst with H3PW12O40 loading of 50 wt% showed the highest yield of 93% in 1.8 h for the Mannich reaction of benzaldehyde, aniline and acetophenone under solvent-free condition. A series of β-aminoketone derivatives were synthesized successfully in the presence of this catalyst. In addition, H3PW12O40/3D-SBA-15 catalyst can be easily recovered and reused four times without significant decrease of the activity. This work provides an improved modification of the three-component Mannich reaction in terms of mild reaction conditions, clean reaction profiles, small quantity of catalyst and a simple workup procedure.                                                Resumen.  El ácido fosfotungstico (PW) se soportó en sílice SBA-15 (3D-SBA-15) y se usó como catalizador heterogéneo en la reacción de Mannich en un solo paso de tres componentes a temperatura ambiente. El catalizador H3PW12O40/3D-SBA-15 se preparó mediante impregnación y se caracterizó por espectroscopia de infrarrojo (FT-IR), microscopia electrónica de barrido (SEM), microscopía electrónica de transmisión (TEM), difracción de rayos-X (XRD), fisisorción de N2 y análisis termogravimétrico (TG). El catalizador 50PW/3D-SBA-15, con una carga de H3PW12O40 del 50% en peso, mostró el rendimiento más alto del 93% en 1.8 h para la reacción de Mannich entre benzaldehído, anilina y acetofenona, sin disolvente. Se sintetizó una serie de derivados de β-aminocetona en presencia de este catalizador. Además, el catalizador H3PW12O40/3D-SBA-15 puede recuperarse fácilmente y reutilizarse cuatro veces sin pérdida significativa de la actividad. Este trabajo reporta una modificación de la reacción de Mannich de tres componentes bajo condiciones de reacción suaves, perfiles de reacción limpios, pequeña cantidad de catalizador y un procedimiento de tratamiento simple.

A Facile and Efficient Method to Prepare Exfoliated and Reduced Graphene Nanosheets by Detonation

2014 ◽  
Vol 937 ◽  
pp. 260-266 ◽  
Author(s):  
Yan Hua Guo ◽  
Dong Xian Zhuo ◽  
Li Xin Wu ◽  
Lin Ma ◽  
Zi Xiang Weng ◽  
...  
Keyword(s):  
Specific Surface ◽  
Graphene Nanosheets ◽  
Low Cost ◽  
High Specific Surface Area ◽  
X Ray Diffraction ◽  
Atomic Force ◽  
Transmission Electron ◽  
Composition And Structure ◽  
Reduced Graphene ◽  
Detonation Method

A facile, efficient, and low energy consumption detonation method to prepare few-layered graphene nanosheets has been developed using graphite oxide as a precursor at detonation induced temperature as low as 100 °C . The composition and structure of as-produced few-layered graphenes were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Fourier Transform Infrared (FTIR), Specific Surface (BET), Transmission Electron Microscopy (TEM), Raman Microscope, and Atomic Force Microscope (AFM). Results showed that the as-produced graphenes were transparent and few-layered with a high specific surface area (225.9 m2/g). The investigation opens a new road to prepare few-layered graphene nanosheets at low exfoliation temperature in a low-cost and facile way.

TEM Sample Fabrication of Sub 22 nm Three-Dimensional Test Structures

2013 ◽  
Author(s):  
James J. Demarest
Keyword(s):  
Sample Preparation ◽  
Semiconductor Device ◽  
Three Dimensional ◽  
Manufacturing Plants ◽  
Transmission Electron ◽  
Device Structures ◽  
Device Integration ◽  
The One ◽  
Device Technology

Abstract With the 14nm technology node becoming a reality at today's state-of-the-art semiconductor manufacturing plants and the 10nm node actively being planned for, device structures have shrunk well beyond the minimum conventional transmission electron microscope (TEM) sample thickness: 50-100nm. This paper addresses the challenges in TEM sample preparation of sub 22nm three-dimensional test structures. As semiconductor device technology continues to shrink and become more complicated with the addition of three-dimensional device integration, unique sample preparation challenges will continue to arise. This opens the door to novel solutions for these problems like the one presented in this paper: an issue that arose where TEM projection effects interfered with proper characterization of a finFET test structure.

Modern Techniques for Automated Acquiring and Processing Data of Diffraction Electron Microscopy for Nano-Materials and Single-Crystals

2020 ◽  
Vol 992 ◽  
pp. 907-915 ◽  
Author(s):  
V. Sydorets ◽  
O. Berdnikova ◽  
Ye. Polovetskyi ◽  
Ye. Titkov ◽  
A. Bernatskyi
Keyword(s):  
Electron Microscope ◽  
Single Crystal ◽  
Single Crystals ◽  
Three Dimensional ◽  
Modern Science ◽  
Nano Materials ◽  
Modern Computer ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Misorientation Angles

Progress in modern science and technology is impossible without the use of new materials, which include nanoparticles and single crystals. Existing approaches in the field of computer vision are difficult to apply to the processing of diffraction patterns, which contain information about the parameters of the fine structure of nanostructured and single-crystal materials. The aim of the work was to develop modern computer-aided techniques that, interacting with the software of the electron microscope, automatically receive and process the information contained in electron diffraction patterns. Replacing the diffraction pattern obtained by a transmission electron microscope with a three-dimensional relief makes it possible to reduce the problem to the solution of the optimization problem. This approach allows not only automating the process of scientific research, but also significantly reduces the time for obtaining the result and increases its accuracy. The application of the proposed approach is demonstrated in measuring the misorientation angles of large single-crystal tungsten ingots, which are obtained by the plasma-induction growing technology.

Improvements in Zone Melt Recrystallized Soi Layers by the Use of Selective Epitaxial Growth in the Seed Windows.

1987 ◽  
Vol 107 ◽  
Author(s):  
D.A. Williams ◽  
R.A. McMahon ◽  
H. Ahmed ◽  
L. Karapiperis ◽  
G. Garry ◽  
...  
Keyword(s):  
Epitaxial Growth ◽  
Three Dimensional ◽  
Silicon Layer ◽  
Silicon On Insulator ◽  
Cross Sectional ◽  
Selective Epitaxial Growth ◽  
Beam System ◽  
Transmission Electron ◽  
The One ◽  
Zone Melt

AbstractThe effect of selective epitaxial growth (SEG) of silicon in the seed windows of silicon on insulator structures prior to recrystallization has been investigated. Subsequent zone melt recrystallization of these structures was performed in a dual electron beam system, and it was found that the full planarisation of the deposited silicon layer results in uniform film thickness after recrystallization. Cross sectional scanning and transmission electron microscopy, optical microscopy after defect etching, and bevelling are used to analyse the material. The SEG method improves the uniformity of the film for device island etching, and so is useful for all silicon on insulator applications, although the one of most interest for these investigations is the production of three dimensional circuitry. This is achieved by stacking layers of devices, and so planarity is particularly important.

Determination of Size Distribution of Elliptical Microvessels from Size Distribution Measurement of Their Section Profiles

2003 ◽  
Vol 228 (1) ◽  
pp. 84-92 ◽  
Author(s):  
R.A. Krasnoperov ◽  
A.N. Gerasimov
Keyword(s):  
Size Distribution ◽  
Three Dimensional ◽  
Axial Ratio ◽  
Minor Radius ◽  
Transmission Electron ◽  
Section Profile ◽  
Ultrathin Sections ◽  
The One ◽  
Major Radius

In transmission electron microscopy, microvessels (MVs) are studied as profiles on ultrathin sections. To determine MV sizes from measurements made on MV profiles, an assumption must be made about MV shape, a circular cylinder being used to approximate the latter on limited lengths. However, this model is irrelevant in case MVs have some flatness. The elliptical cylinder model is preferable, although relationships between the cylinder profile (two-dimensional; 2D) and its true (three-dimensional; 3D) sizes are not yet known. We have obtained the 2D/3D functions that express the relationships between such profile sizes as the minor radius (Y), major radius (X), axial ratio (X/Y), area (S), and perimeter (P) on the one hand, and the corresponding MV sizes (Y0, X0, X0/Y0, S0, and P0) on the other. The 2D/3D functions make it possible to derive elliptical MV sizes from section profile size distributions, probability density functions (PDFs) for the latter being determined. We have applied the 2D/3D functions in studying axial ratios of thyroid hemocapillaries. A factual X/Y frequency histogram has been constructed and fitted by theoretical X/Y PDFs plotted for different sets of capillary sizes. The thyroid capillaries have been revealed to be clustered, 72.7% of them having X0/Y0 ≈ 1.6, 17.6%, X0/Y0 ≈ 1.0. and 9.7%, X0/Y0 ≈ 3.2. The proposed technique is instrumental in precise modeling of microclrculatory network geometry.

Three-Dimensional Reconstruction Using Stereo Pairs from Serial Thick Sections

1977 ◽  
Vol 35 ◽  
pp. 562-563
Author(s):  
Robert Glaeser ◽  
Thomas Bauer ◽  
David Grano
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Serial Sections ◽  
Thin Sections ◽  
3 Dimensional ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Dimensional Reconstruction ◽  
Stereo Imagery ◽  
Whole Mounts

In transmission electron microscopy, the 3-dimensional structure of an object is usually obtained in one of two ways. For objects which can be included in one specimen, as for example with elements included in freeze- dried whole mounts and examined with a high voltage microscope, stereo pairs can be obtained which exhibit the 3-D structure of the element. For objects which can not be included in one specimen, the 3-D shape is obtained by reconstruction from serial sections. However, without stereo imagery, only detail which remains constant within the thickness of the section can be used in the reconstruction; consequently, the choice is between a low resolution reconstruction using a few thick sections and a better resolution reconstruction using many thin sections, generally a tedious chore. This paper describes an approach to 3-D reconstruction which uses stereo images of serial thick sections to reconstruct an object including detail which changes within the depth of an individual thick section.

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