scholarly journals Synthesis, Characterization and Photocatalytic Activity of Nanocrystalline First Transition-Metal (Ti, Mn, Co, Ni and Zn) Oxisde Nanofibers by Electrospinning

2018 ◽  
Vol 9 (1) ◽  
pp. 8 ◽  
Author(s):  
Yu Chen ◽  
Weipeng Lu ◽  
Yanchuan Guo ◽  
Yi Zhu ◽  
Haojun Lu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Transition Metal ◽  
Metal Oxide ◽  
Specific Surface ◽  
Three Dimensional ◽  
Photogenerated Electron ◽  
Practical Applications ◽  
Surface Areas ◽  
Tio2 Nanofiber ◽  
Transmission Electron

In this work, five nanocrystalline first transition-metal (Ti, Mn, Co, Ni and Zn) oxide nanofibers were prepared by electrospinning and controlled calcination. The morphology, crystal structure, pore size distribution and specific surface area were systematically studied by scanning electron microscope (SEM), transmission electron microscope (TEM), surface and pore analysis, and thermo gravimetric analyzer (TGA). The results reveal that the obtained nanofibers have a continuously twisted three-dimensional scaffold structure and are composed of neat nanocrystals with a necklace-like arrangement. All the samples possess high specific surface areas, which follow the order of NiO nanofiber (393.645 m2/g) > TiO2 nanofiber (121.445 m2/g) > ZnO nanofiber (57.219 m2/g) > Co3O4 nanofiber (52.717 m2/g) > Mn2O3 nanofiber (18.600 m2/g). Moreover, the photocatalytic degradation of methylene blue (MB) in aqueous solution was investigated in detail by employing the five kinds of metal oxide nanofibers as photocatalysts under ultraviolet (UV) irradiation separately. The results show that ZnO, TiO2 and NiO nanofibers exhibit excellent photocatalytic efficiency and high cycling ability to MB, which may be ascribed to unique porous structures and the highly efficient separation of photogenerated electron-hole pairs. In brief, this paper aims to provide a feasible approach to achieve five first transition-metal oxide nanofibers with excellent performance, which is important for practical applications.

Transition metal oxide and chalcogenide-based nanomaterials for antibacterial activities: an overview

Nanoscale ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 6373-6388
Author(s):  
Yanan Tang ◽  
Zhen Qin ◽  
Shengyan Yin ◽  
Hang Sun
Keyword(s):  
Transition Metal ◽  
Metal Oxide ◽  
Transition Metal Oxide ◽  
Antibacterial Activities ◽  
Practical Applications ◽  
Recent Advances

This review summarizes the recent advances of transition metal oxide and chalcogenide-based antibacterial nanomaterials, with emphasis on their inactivation mechanisms and highlighting their practical applications.

scholarly journals Meso-Scale Transmission Electron Microscope Tomography Applied for Wax Distribution in Toner Particles

2013 ◽  
Vol 19 (S5) ◽  
pp. 58-61 ◽  
Author(s):  
Mino Yang ◽  
Jun-Ho Lee ◽  
Hee-Goo Kim ◽  
Euna Kim ◽  
Young-Nam Kwon ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Three Dimensional ◽  
Chromatic Aberration ◽  
Laser Printer ◽  
Medium Voltage ◽  
Transmission Electron ◽  
Z Contrast ◽  
Contrast Image

AbstractDistribution of wax in laser printer toner was observed using an ultra-high-voltage (UHV) and a medium-voltage transmission electron microscope (TEM). As the radius of the wax spans a hundred to greater than a thousand nanometers, its three-dimensional recognition via TEM requires large depth of focus (DOF) for a volumetric specimen. A tomogram with a series of the captured images would allow the determination of their spatial distribution. In this study, bright-field (BF) images acquired with UHV-TEM at a high tilt angle prevented the construction of the tomogram. Conversely, the Z-contrast images acquired by the medium-voltage TEM produced a successful tomogram. The spatial resolution for both is discussed, illustrating that the image degradation was primarily caused by beam divergence of the Z-contrast image and the combination of DOF and chromatic aberration of the BF image from the UHV-TEM.

Fast Throughput Low Voltage Scanning Transmission Electron Microscope Imaging of Nano-Resolution Three Dimensional Tissue

2009 ◽  
Vol 15 (S2) ◽  
pp. 642-643
Author(s):  
M Bolorizadeh ◽  
HF Hess
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Low Voltage ◽  
Three Dimensional ◽  
Scanning Transmission Electron Microscope ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Microscope Imaging ◽  
Electron Microscope Imaging ◽  
Voltage Scanning

Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009

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.

scholarly journals Ultrastructure of Human Fertile Hydatid Cysts Using a Scanning Electron Microscope (SEM)

2020 ◽  
Vol 1 (3) ◽  
pp. 52-55
Author(s):  
Hadi M. Hamza Al-Mayali ◽  
Hind A. Abdul Kadhim
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Three Dimensional ◽  
Zoonotic Diseases ◽  
Hydatid Cysts ◽  
Germinal Layer ◽  
Transmission Electron ◽  
The World ◽  
Laminated Layer ◽  
Scanning Electron

Introduction: Echinococcosis and hydatidosis caused by the metacestode of Echinococcus granulosus are among the most important zoonotic diseases in the world. This study aims to study the ultrastructure of fertile hydatid cysts that infect humans using a scanning electron microscope (SEM). Materials and Methods: Twenty samples of human fertile hydatid cysts were collected from the human liver and lung after performing surgery operations and examined with an SEM. Results: The results of the electron microscopy with different magnifications revealed that the laminated layer (LL) consists of sheets that appeared more compact and aligned. The brood capsules appeared, consisting of a net of finger-shaped structures that emerged from bulges of various sizes and shapes. Conclusion: Under a transmission electron microscope, it was found that the LL had a coherent and flexible structure, settling on a three-dimensional microscopic network of hydrophilic fibers, with high humidity. These fibers were arranged irregularly and had a diameter of about 10 nm; therefore, the fibers adjacent to the germinal layer (GL) were possibly attached to microtriches of tegument, which reached a thickness of 1 mm in the LL.

Study on Sn-Fe-Cr Composite Oxides: Novel, Active and Thermally Stable Catalysts for CH4 Total Oxidation

2002 ◽  
Vol 216 (7) ◽  
Author(s):  
X. Wang ◽  
Y. Xie
Keyword(s):  
Thermal Stability ◽  
Metal Oxide ◽  
Specific Surface ◽  
Redox Reaction ◽  
Metal Oxide Catalysts ◽  
Total Oxidation ◽  
Surface Areas ◽  
Composite Oxides ◽  
Specific Surface Areas ◽  
Co Precipitation

With the combination of redox reaction and co-precipitation, a series of Sn-Fe-Cr composite metal oxide catalysts with various compositions were prepared, which exhibit higher specific surface areas, thermal stability and CH

Electron Microscope Studies of Some Vapor Deposited Materials: Nucleation, Epitaxial Growth and Surface Topography

1991 ◽  
Vol 237 ◽  
Author(s):  
William Krakow
Keyword(s):  
Electron Microscope ◽  
Epitaxial Growth ◽  
Three Dimensional ◽  
Film Surface ◽  
Ex Situ ◽  
Growth Regime ◽  
Growth Modes ◽  
Transmission Electron ◽  
Resolution Electron ◽  
High Resolution Electron Microscope

ABSTRACTThe nucleation and epitaxial growth of deposits at both low and high temperature substrate conditions and the resulting two and three dimensional growth modes have been investigated using electron diffraction and transmission electron microscopy. At high temperatures, the growth of small particles such as Au, Pt and Ge grown under low rate conditions similar to MBE are revealed by lattice imaging. Using an intermediate bufler layer Ag film, surface growth of (100) and (310) Au thin film layers are revealed by diffraction contrast to be in a step ledge growth regime. While the above investigations were performed ex situ to the microscope vacuum environment, an in situ evaporator has been also been installed on a high resolution electron microscope. Observations can be made in real time of cluster growth from atomic diameters on up. The resulting atomic motion around cluster edges is similar in appearance to surface melting.

Analysis of electron-specimen interactions of thick biological specimens in Transmission Electron Microscopy at 200 KEV

1993 ◽  
Vol 51 ◽  
pp. 204-205
Author(s):  
Karen F. Han ◽  
Alexander J. Gubbens ◽  
Abraham J. Koster ◽  
Michael B. Braunfeld ◽  
John W. Sedat ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Mass Density ◽  
Three Dimensional ◽  
Chromatic Aberration ◽  
Background Intensity ◽  
Objective Lens ◽  
Dimensional Electron ◽  
Accurate Representation ◽  
Transmission Electron

The primary project of our laboratory is the investigation of chromatin structure by three dimensional electron microscope tomography. The goal is to understand how 30nm fibers fold into higher order chromatin structures. Three dimensional tomography involves the reconstruction of an object by combining multiple projection views of the object at different tilt angles. Due to the electronspecimen interaction and the characteristics of lens aberration in the electron microscope, however, the image is not always an accurate representation of the projected object mass density. In this abstract, we analyze the various types of electron-specimen interaction for thick biological specimens up to 0.7 microns thickness.Electron-specimen interactions include single elastic and inelastic, and multiple elastic and inelastic scattering. Of the imaging electrons, the single elastic and the plasmon electrons give rise to image intensities that can be linearly related to the projected object mass density. Multiply scattered elastic electrons contribute to an increase in background intensity. In addition, due to the chromatic aberration of the TEM’s objective lens, multiply scattered inelastic electrons cause a blurring of the image because of an effective broadening of the focus spread.

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