scholarly journals ZnO Nanoparticles with Controllable Ce Content for Efficient Photocatalytic Degradation of MB Synthesized by the Polyol Method

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 71
Author(s):  
Gregorio Flores-Carrasco ◽  
Micaela Rodríguez-Peña ◽  
Ana Urbieta ◽  
Paloma Fernández ◽  
María Eugenia Rabanal
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Degradation ◽  
Doping Concentration ◽  
Polyol Method ◽  
Transmission Microscopy ◽  
Uv Illumination ◽  
Transmission Electron ◽  
Optical Luminescence ◽  
Pl Emission ◽  
Ce Content

This paper reports on the synthesis of Ce-doped ZnO (CZO) nanoparticles (NPs) by an alternative polyol method at low temperature. The method, facile and rapid, uses acetate-based precursors, ethylene glycol as solvent, and polyvinylpyrrolidone as capping agent. The effects of the Ce-doping concentration (ranging from 0 to 8.24 atomic%) on the structural, morphological, compositional, optical, luminescence, and photocatalytic properties of the NPs were investigated by several techniques. The structural findings confirmed that the CZO NPs have a typical hexagonal wurtzite-type structure with a preferred orientation along the (101) plane. The results obtained by Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM) revealed that the NPs size decreased (from ~30 to ~16 nm) with an increase in the Ce-doping concentration. Energy Dispersive X-Ray Spectroscopy (EDS) and High Resolution Transmission Microscopy (HRTEM) results confirmed the incorporation of Ce ions into the ZnO lattice. Ce-doping influences the photoluminescence (PL) emission compared to that of pure ZnO. The PL emission is related to the presence of different kinds of defects, which could take part in charge transfer and/or trapping mechanisms, hence playing an essential role in the photocatalytic activity (PCA). In fact, in this work we report an enhancement of PCA as a consequence of Ce-doping. In this sense, the best results were obtained for samples doped with 3.24 atomic%, that exhibited a photocatalytic degradation efficiency close to 99% after 60 min ultraviolet (UV) illumination, thus confirming the viability of Ce-doping for environmental applications.

Scanning and Transmission Microscopy of Nematocyst Batteries in Epitheliomuscular Cells of Hydra

1971 ◽  
Vol 29 ◽  
pp. 410-411 ◽  
Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Osmium Tetroxide ◽  
External Surface ◽  
Three Dimensional ◽  
Surface Structures ◽  
Transmission Microscopy ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Scanning Electron

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).

scholarly journals Synthesis of TiO2/Pd and TiO2/PdO Hollow Spheres and Their Visible Light Photocatalytic Activity

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Jing Yan ◽  
Xiaojuan Li ◽  
Bo Jin ◽  
Min Zeng ◽  
Rufang Peng
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Diffuse Reflectance Spectroscopy ◽  
Hollow Spheres ◽  
Active Species ◽  
Degradation Efficiency ◽  
Diffraction Field ◽  
Transmission Electron

A series of TiO2, TiO2/Pd, and TiO2/PdO hollow sphere photocatalysts was successfully prepared via a combination of hydrothermal, sol-immobilization, and calcination methods. The structure and optical properties of the as-prepared samples were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Telleranalysis, Barrett-Joyner-Halenda measurement, and UV-Vis diffuse reflectance spectroscopy. The photocatalysis efficiencies of all samples were evaluated through the photocatalytic degradation of rhodamine B under visible light irradiation. Results indicated that TiO2/PdO demonstrated a higher photocatalytic activity (the photocatalytic degradation efficiency could reach up to 100% within 40 min) than the other samples and could maintain a stable photocatalytic degradation efficiency for at least four cycles. Finally, after using different scavengers, superoxide and hydroxyl radicals were identified as the primary active species for the effectiveness of the TiO2/PdO photocatalyst.

Microstructure and Properties of Cu-Cr-Zr-Ag Alloy

2018 ◽  
Vol 941 ◽  
pp. 1613-1617 ◽  
Author(s):  
Li Jun Peng ◽  
Xu Jun Mi ◽  
Hao Feng Xie ◽  
Yang Yu ◽  
Guo Jie Huang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Phase Transformation ◽  
High Resolution ◽  
Aging Process ◽  
Precipitation Sequence ◽  
Transmission Microscopy ◽  
Transmission Electron ◽  
The Matrix

The Cr precipitation sequence in Cu-Cr-Zr-Ag alloy during the aging process at 450°C could be obtained by Transmission electron microscopy (TEM) and High-resolution transmission microscopy (HRTEM) in the study. The strengthening curve shows a unimodal type and the tensile strength trends to peak when the aged for 4h. The Cr phase transformation of Cu-Cr-Zr-Ag aged at 450°C is supersaturated solid sloution→G.P zones→fcc Cr phase→order fcc Cr phase→bcc Cr phase. The orientation relationship between bcc Cr precipitates and the matrix change from cube-on-cube to NW-OR.

Effect of Dopant Concentration on the Growth of Oxide Precipitates in Silicon

1984 ◽  
Vol 36 ◽  
Author(s):  
Satoru Matsumoto ◽  
Ichiro Ishihara ◽  
Hiroyuki Kaneko ◽  
Hirofumi Harada ◽  
Takao Abe
Keyword(s):  
Electron Microscopy ◽  
Doping Concentration ◽  
Dopant Concentration ◽  
The Other ◽  
Boron Doped ◽  
Transmission Electron ◽  
Precipitate Growth ◽  
Doped Silicon ◽  
Phosphorus Doped ◽  
Precipitate Density

ABSTRACTThe dependences of dopant species and concentrations on the growth of oxide precipitates have been studied using transmission electron microscopy. Doping species are phosphorus, antimony and boron. Samples were annealed at 800°C and 850°C for 24∼384hr in dry nitrogen. In phosphorus-doped silicon, the precipitate density is independent of doping concentration and the growth of precipitate obeys the three-quarter power law. The enhancement of the precipitate growth is observed in antimony-doped silicon. On the other hand, the precipitate growth is suppressed in heavily boron-doped silicon as compared with that of lightly boron-doped silicon. This indicates the generation of excess silicon interstitials in heavily boron-doped silicon.

Nanostructure of Porous Silicon Using Transmission Microscopy

1998 ◽  
Vol 536 ◽  
Author(s):  
M. H. Nayfeh ◽  
Z. Yamani ◽  
O. Gurdal ◽  
A. Alaql
Keyword(s):  
Electron Microscopy ◽  
Diffuse Scattering ◽  
Amorphous State ◽  
Coherent Scattering ◽  
Porous Si ◽  
Island Size ◽  
Transmission Microscopy ◽  
Transmission Electron ◽  
Uppermost Layer ◽  
P Type

AbstractWe use high resolution transmission electron microscopy (XTEM) to image the nanostructure of (100) p-type porous Si. A network of pore tracks subdivide the material into nanoislands and nanocrystallites are resolved through out the material. With distance from the substrate, electron diffraction develops, in addition to coherent diffraction, amorphous-like patterns that dominates the coherent scattering in the topmost luminescent layer. Also, with distance from the substrate, crystalline island size diminshes to as small as 1 nm in the topmost luminescence material. Although their uppermost layer has the most resolved nano crystallites, it has the strongest diffuse scattering of all regions. This suggests that the diffuse scattering is due to a size reduction effects rather than to an amorphous state. We discuss the relevance of a new dimer restructuring model in ultra small nanocrystallites to the loss of crystalline effects.

In-Grown Stacking Faults Identified in 4H-SiC Epilayers Grown at High Growth Rate

2010 ◽  
Vol 645-648 ◽  
pp. 287-290 ◽  
Author(s):  
Gan Feng ◽  
Jun Suda ◽  
Tsunenobu Kimoto
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Stacking Faults ◽  
High Growth ◽  
High Growth Rate ◽  
Emission Peak ◽  
Formation Model ◽  
Intensity Mapping ◽  
Transmission Electron ◽  
Pl Emission

In-grown stacking faults (IGSFs) in thick 4H-SiC epilayers grown at high growth rates have been characterized by micro-photoluminescence (micro-PL) spectroscopy and its intensity mapping. Strong PL emissions from the IGSFs are observed even at room temperature. Three kinds of IGSFs have been identified in the samples based on the micro-PL spectra. Each IGSF shows the specific PL emission peak located at 460 nm, 480 nm, and 500 nm, respectively. The shapes, distributions, and densities of IGSFs in the epilayers are revealed by the micro-PL intensity mapping. The stacking sequences of three IGSFs have been determined as (4,4), (3,5), and (6,2) in the Zhadonov’s notation, respectively, by high-resolution transmission electron microscopy observations. Three identified IGSFs are then classified as quadruple Shockley SFs, triple Shockley SFs, and double Shockley SFs, respectively, based on the shear formation model.

scholarly journals Analysis by Light, Scanning, and Transmission Microscopy of the Intima Synovial of the Temporomandibular Joint of Human Fetuses during the Development

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Carlos Sabu Alvez ◽  
Luis Otavio Carvalho de Moraes ◽  
Sergio R. Marques ◽  
Roberto C. Tedesco ◽  
Leandro J. C. Harb ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Light Microscopy ◽  
Temporomandibular Joint ◽  
Cell Types ◽  
Human Fetuses ◽  
Transmission Microscopy ◽  
Joint Cavity ◽  
Transmission Electron ◽  
Intima Layer

Objective. To characterize morphologically and ultrastructurally using light microscopy, the scanning electron microscopy and transmission electron microscopy the intima synovial of the temporomandibular joint (TMJ) of human fetuses between the 10th and the 38th week of development. Materials and Methods. The TMJ was dissected bilaterally in 37 human fetuses belonging to the Institute of Embryology of the University Complutense of Madrid and of the Federal University of São Paulo. Results. The outcome by light microscopy showed the morphology of the TMJ and that the formation of inferior joint cavity precedes the superior joint cavity and the presence of blood vessels in the synovial. Conclusion. By scanning and transmission electron microscopy we observed the presence of two well-defined cell types in the intima layer of synovial of the TMJ of human fetuses, macrophage-like type A cell and fibroblast-like type B cell, and the presence of the a third cell type, defined by the name of intermediate lining cell in the intima layer of the synovial.

scholarly journals One-Dimensional TiO2-B Crystals Synthesised by Hydrothermal Process and Their Antibacterial Behaviour onEscherichia coli

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Sergio León-Ríos ◽  
Rodrigo Espinoza González ◽  
Sandra Fuentes ◽  
Emigdio Chávez Ángel ◽  
Alex Echeverría ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Monoclinic Phase ◽  
Hydrothermal Process ◽  
Morphological Characterization ◽  
One Dimensional ◽  
Uv Illumination ◽  
Transmission Electron ◽  
Pure Cultures ◽  
Diffraction Patterns ◽  
The One

We have successfully synthesised one-dimensional single crystals of monoclinic phase titanium dioxide nanostructures (TiO2-B), prepared by a hydrothermal process. Morphological characterization was carried out by atomic force and scanning and transmission electron microscopy techniques. In order to study the crystalline structure, samples were calcined at 500°C in an air-filled chamber. X-ray diffraction results indicated that as-prepared samples presented diffraction patterns of hydrate hydrogen titanate and those calcined at 500°C exhibited the TiO2-B and anatase phases, confirmed by Raman spectroscopy. Scanning electron microscopy results showed that the one-dimensional nanostructures had high contrast and uniform widths for those synthesised and calcined, indicating the formation of a phase of monocrystals. Besides, a proof of the antibacterial effect was carried out of the monoclinic phase of TiO2-B onEscherichia colipure cultures, where the viability of the bacterium decreases in presence of TiO2-B nanostructures plus UV illumination. Monocrystals did not change after photocatalytic tests, suggesting a possible application as long-term antibacterial protection.

Characterization of Y/TiO2 Nanoparticles and their Reactivity for CO2 Photoreduction

2011 ◽  
Vol 55-57 ◽  
pp. 1506-1510 ◽  
Author(s):  
Jing Wei ◽  
Xin Tan ◽  
Tao Yu ◽  
Lin Zhao
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Illumination ◽  
Transmission Electron ◽  
And Chemical Properties

A series of Y/TiO2nanoparticles (NPs) were synthesized via sol-gel method. The crystal structures, morphologies and chemical properties were characterized using X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS). We investigated the effects of different doping amounts of Y on the reaction of CO2photoreduction. The results shown that 0.1 wt.%Y/TiO2(0.1YT) performed the highest photocatalytic activity, which yielded 384.62 µmol/g∙cat. formaldehyde after 6 h of UV illumination.

scholarly journals Electron Microscopy of Spinodal Alloys

1970 ◽  
Vol 28 ◽  
pp. 450-451
Author(s):  
R. J. Livak ◽  
G. Thomas
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Acetic Acid Solution ◽  
Heat Treating ◽  
Transmission Microscopy ◽  
Nickel Iron ◽  
Thin Foils ◽  
Transmission Electron ◽  
Kinetics Of ◽  
Acetic Acids

Transmission microscopy, electron diffraction and scanning microscopy were used to study directly the microstructure of spinodal alloys and to correlate the fracture mode of aged tensile specimens with the microstruetural changes. The kinetics of spinodal decomposition for two copper-nickel-iron alloys were experimentally studied by heat treating specimens as described by Butler and Thomas. The aging times inside the spinodal ranged from one minute to 1000 hours. Thin foils for transmission electron microscopy were prepared by first using a chemical polish containing nitric, hydrochloric and acetic acids and then by electropolishing in a chromic oxide-acetic acid solution.

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