scholarly journals Preparation of Porous F-WO3/TiO2Films with Visible-Light Photocatalytic Activity by Microarc Oxidation

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Chung-Wei Yeh ◽  
Kee-Rong Wu ◽  
Chung-Hsuang Hung ◽  
Hao-Cheng Chang ◽  
Chuan-Jen Hsu
Keyword(s):  
Visible Light ◽  
Dye Degradation ◽  
Microarc Oxidation ◽  
Band Gap Energy ◽  
High Specific Surface Area ◽  
Cross Sectional ◽  
Porous Networks ◽  
Transmission Electron ◽  
Porous Microstructure ◽  
Diffraction Patterns

Porous F-WO3/TiO2(mTiO2) films are prepared on titanium sheet substrates using microarc oxidation (MAO) technique. The X-ray diffraction patterns show that visible-light (Vis) enabling mTiO2films with a very high content of anatase TiO2and high loading of WO3are successfully synthesized at a low applied voltage of 300 V using electrolyte contenting NaF and Na2WO4without subsequent heat treatment. The cross-sectional transmission electron microscopy micrograph reveals that the mTiO2films feature porous networks connected by many micron pores. The diffused reflection spectrum displays broad absorbance across the UV-Vis regions and a significant red shift in the band gap energy (∼2.23 eV) for the mTiO2film. Owing to the high specific surface area from the porous microstructure, the mTiO2film shows a 61% and 50% rate increase in the photocatalytic dye degradation, as compared with the N,C-codoped TiO2films under UV and Vis irradiation, respectively.

Observation of the Wurtzite Phase in OMVPE Grown ZnSe/GaAs: Effect on Implantation and Rapid Thermal Annealing

1989 ◽  
Vol 147 ◽  
Author(s):  
K. S. Jones ◽  
J. Yu ◽  
P. D. Lowen ◽  
D. Kisker
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Electrical Transport ◽  
High Resistivity ◽  
Ion Milling ◽  
Electrical Transport Properties ◽  
Wurtzite Phase ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Diffraction Patterns

AbstractTransmission electron diffraction patterns of cross-sectional TEM samples of OMVPE ZnSe on GaAs indicate the existence of the hexagonal wurtzite phase in the epitaxial layers. The orientation relationship is (0002)//(111); (1120)//(220). Etching studies indicate the phase is internal not ion milling induced. The average wurtzite particle size is 80Å-120Å. Because of interplanar spacing matches it is easily overlooked. Electrical property measurements show a high resistivity (1010ω/square) which drops by four orders of magnitude upon rapid thermal annealing between 700°C and 900 °C for 3 sec. Implantation of Li and N have little effect on the electrical transport properties. The Li is shown to have a high diffusivity, a solid solubility of ≈1016/cm3 at 800°C and getters to the ZnSeA/aAs interface.

scholarly journals The Reliability Improvement of Cu Interconnection by the Control of Crystallizedα-Ta/TaNxDiffusion Barrier

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Wei-Lin Wang ◽  
Chia-Ti Wang ◽  
Wei-Chun Chen ◽  
Kuo-Tzu Peng ◽  
Ming-Hsin Yeh ◽  
...  
Keyword(s):  
Diffusion Barrier ◽  
Practical Application ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Reliability Improvement ◽  
N Concentration ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Interconnection Structure

Ta/TaN bilayers have been deposited by a commercial self-ionized plasma (SIP) system. The microstructures of Ta/TaN bilayers have been systematically characterized by X-ray diffraction patterns and cross-sectional transmission electron microscopy. TaN films deposited by SIP system are amorphous. The crystalline behavior of Ta film can be controlled by the N concentration of underlying TaN film. On amorphous TaN film with low N concentration, overdeposited Ta film is the mixture ofα- andβ-phases with amorphous-like structure. Increasing the N concentration of amorphous TaN underlayer successfully leads upper Ta film to form pureα-phase. For the practical application, the electrical property and reliability of Cu interconnection structure have been investigated by utilizing various types of Ta/TaN diffusion barrier. The diffusion barrier fabricated by the combination of crystallizedα-Ta and TaN with high N concentration efficiently reduces the KRc and improves the EM resistance of Cu interconnection structure.

scholarly journals Improvement of the Efficiency of TiO2 Photocatalysts with Natural Dye Sensitizers Anthocyanin for the Degradation of Methylene Blue: Review

2021 ◽  
Vol 16 (2) ◽  
pp. 84-99
Author(s):  
Hendrini Pujiastuti ◽  
Indar Kustiningsih ◽  
Slamet Slamet
Keyword(s):  
Visible Light ◽  
Dye Degradation ◽  
Low Cost ◽  
Electron Excitation ◽  
Band Gap Energy ◽  
Natural Dye ◽  
Tio2 Photocatalyst ◽  
Tio2 Photocatalysts ◽  
Dye Sensitizer ◽  
Potential Methods

One of the potential methods utilized for dye degradation is photocatalitic, due to its low cost, highly effective, and environmentally friendly. Effectivenes of TiO2 photocatalysts can be enhanced by adding a dye sensitizer. Dye-sensitizer material absorbs visible light to facilitate electron excitation process. Addition of dye-sensitizer on TiO2 photocatalyst promotes it to be more responsive to visible light. Natural anthocyanin dyes are often used as sensitizers of TiO2 semiconductors. Anthocyanins are, usually in the purple to the red color range, a group of natural dyes found in the flowers, leaves, and fruit of plants. The essential principles of dye sensitization to TiO2 have been explored in this review. It is feasible to reduce the band gap energy in the TiO2 photocatalyst by modifying it using a natural dye sensitized modification. Dye sensitizers on TiO2 nanotubes plate have the potential to be employed in a dye degradation photocatalytic system

Novel plate-stratiform nanostructured Bi12O17Cl2 with visible-light photocatalytic performance

2016 ◽  
Vol 31 (1) ◽  
pp. 2-7 ◽  
Author(s):  
Mei Zhao ◽  
Lifeng Dong ◽  
Qian Zhang ◽  
Hongzhou Dong ◽  
Chengdong Li ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Performance ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Visible Light Photocatalytic ◽  
Excellent Photostability

Novel plate-stratiform nanostructured Bi12O17Cl2 was studied with its visible-light photocatalytic performance. The Bi12O17Cl2 photocatalyst synthesized by a solid-state reaction was constructed of dozens of primary nanosheets, which were stacked by a parallel array of ultrathin secondary nanosheets. The microstructure and crystal structure of Bi12O17Cl2 primary and secondary nanosheets were discovered by high-resolution transmission electron microscopy and selected-area electron diffraction analyses. Its absorption edge was determined as about 590 nm and the band gap energy was 2.1 eV. The Bi12O17Cl2 nanomaterial exhibited superior visible-light-responsive photocatalytic activity and confirmed successful photodegradation of methyl orange (MO) under visible-light irradiation. The degradation efficiency was up to 97% in 90 min. Furthermore, the Bi12O17Cl2 photocatalyst exhibited excellent photostability and high mineralization capacity for MO photodegradation reaction. The MO photodegradation process was dominated by the direct photocatalytic mechanism. The contribution from its morphology and microstructure to superior photocatalytic activity was discussed.

Microstructural study of MBE-grown ZnO film on GaN/sapphire (0001) substrate

Open Physics ◽  
2008 ◽  
Vol 6 (3) ◽  
Author(s):  
Hua Li ◽  
Jianping Sang ◽  
Chang Liu ◽  
Hongbing Lu ◽  
Juncheng Cao
Keyword(s):  
Interface Layer ◽  
Interfacial Microstructure ◽  
X Ray Diffraction ◽  
Zno Film ◽  
Epitaxial Relationship ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Gan Heterostructure

AbstractSingle crystalline ZnO film is grown on GaN/sapphire (0001) substrate by molecular beam epitaxy. Ga2O3 is introduced into the ZnO/GaN heterostructure intentionally by oxygen-plasma pre-exposure on the GaN surface prior to ZnO growth. The crystalline orientation and interfacial microstructure are characterized by X-ray diffraction and transmission electron microscopy. X-ray diffraction analysis shows strong c-axis preferred orientation of the ZnO film. Cross-sectional transmission electron microscope images reveal that an additional phase is formed at the interface of ZnO/GaN. Through a comparison of diffraction patterns, we confirm that the interface layer is monoclinic Ga2O3 and the main epitaxial relationship should be $$ (0001)_{ZnO} \parallel (001)_{Ga_2 O_3 } \parallel (0001)_{GaN} $$ and $$ [2 - 1 - 10]_{ZnO} \parallel [010]_{Ga_2 O_3 } \parallel [2 - 1 - 10]_{GaN} $$.

scholarly journals One Pot Synthesis of CoTiO3-TiO2 Composite Nanofibers and its Application in Dye Degradation

2021 ◽  
pp. 1597-1607
Author(s):  
M. Shamshi Hassan
Keyword(s):  
Visible Light ◽  
Composite Nanofibers ◽  
Dye Degradation ◽  
Band Gap Energy ◽  
One Pot ◽  
Light Region ◽  
Composite Photocatalysts ◽  
One Step ◽  
Ft Ir ◽  
The One

CoTiO3-TiO2 composite nanofibrous photocatalysts were synthesized by means of the one-step electrospinning method. The samples were characterized by a range of different methods (XRD, SEM, EPMA, FT-IR, UV-DRS, and TEM). Photocatalytic activity was performed for the degradation of rhodamine 6G under visible light. The results showed that CoTiO3-TiO2 composite photocatalysts were successfully synthesized. The average sizes of the diameters of the composite nanofibers were found to be 300 to 400 nm. The UV–Vis diffuse reflectance spectra of the CoTiO3-TiO2 composite showed an absorption wavelength, in the visible light region, having a band gap energy value of 2.21 eV. The CoTiO3-TiO2 composite showed higher photocatalytic efficiency than that of pristine TiO2; which can be attributed to the heterojunctional interaction between CoTiO3 and TiO2.

Ordering In Zn0.5Fe0.5Se Epilayers Grown on InP Substrates by Molecular Beam Epitaxy

1991 ◽  
Vol 231 ◽  
Author(s):  
L. Salamanca Riba ◽  
K. Park ◽  
B. T. Jonker
Keyword(s):  
High Resolution ◽  
Ordered Structure ◽  
Cross Sectional ◽  
Zinc Blende ◽  
Transmission Electron ◽  
Lattice Images ◽  
High Resolution Images ◽  
Diffraction Patterns ◽  
Inp Substrates ◽  
Image Simulations

AbstractWe have observed an ordered structure in Zn0.5Fe0.5Se epilayers grown on (001) InP substrates using transmission electron microscopy. The ordered structure of Zn0.5Fe0.5Se has Fe atoms occupying the (0,0,0) and (½, ½, 0) sites and Zn atoms occupying the (0, ½, ½) and (½, 0, ½) sites in the zinc-blende unit cell. Ordering is observed in both electron diffraction patterns and cross-sectional high-resolution lattice images along the < 100 > and < 110 > directions. This ordered structure consists of alternating ZnSe and FeSe monolayers along the < 100 > and < 110 > directions. Computer image simulations of the high-resolution images under various thicknesses, and defocusing conditions have been obtained and are compared with those obtained experimentally.

Nanostructural characterizations of hydrogen-permselective Si–Co–O membranes by transmission electron microscopy

2009 ◽  
Vol 24 (2) ◽  
pp. 372-378 ◽  
Author(s):  
Shinji Fujisaki ◽  
Koji Hataya ◽  
Tomohiro Saito ◽  
Shigeo Arai ◽  
Yuji Iwamoto ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gas Permeation ◽  
Hydrogen Gas ◽  
Transmission Electron Microscopy Micrographs ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Diffraction Patterns ◽  
Permeation Properties

Nanostructural characterizations of liquid metal–organic precursors-derived cobalt-doped amorphous silica (Si–Co–O) membranes supported on a mesoporous anodic alumina capillary (MAAC) tube were performed to study their unique high-temperature hydrogen gas permeation properties. Cross-sectional scanning transmission electron microscopy images and selected-area electron diffraction patterns indicated that the metal cobalt and the different oxidation states of cobalt oxides (CoO and Co3O4) nanocrystallites having a size range of 5–20 nm were in situ formed in the mesopore channels of the MAAC tube. In addition, high-resolution transmission electron microscopy micrographs and electron energy loss spectroscopy elemental mapping images indicated that the highly dense Co-doped amorphous Si–O formed within the mesopore channels of the MAAC tube. These nanostructural features could contribute to the hydrogen-selective permeation properties observed for the membranes.

Vanadium-Decorated Nickel Oxide Nanosheets for Photocatalytic Removal of Malachite Green Dye Using Visible Light

2019 ◽  
Vol 11 (10) ◽  
pp. 1410-1416 ◽  
Author(s):  
A. S. Basaleh
Keyword(s):  
Visible Light ◽  
Nickel Oxide ◽  
Malachite Green ◽  
Photocatalytic Performance ◽  
Dye Degradation ◽  
Weight Percent ◽  
Band Gap Energy ◽  
Bandgap Energy ◽  
Malachite Green Dye ◽  
Photocatalytic Removal

Nickel oxide (NiO) nanosheets were prepared using a hydrothermal method, and vanadiumdecorated nickel oxide nanosheets were prepared using a photoassisted deposition method. The NiO and vanadium-decorated nickel oxide (V @ NiO) photocatalysts were investigated by several techniques, including BET, XPS, PL, UV-Vis, XRD, and TEM. The results demonstrated that the NiO bandgap energy can be adjusted by adjusting the weight percent of decorated vanadium. Malachite green dye degradation under visible light conditions was chosen to measure the photocatalytic performance of the NiO and V @ NiO samples. Additionally, parameters that affect photocatalytic performance, such as the concentration of malachite green dye, dose of the photocatalyst and vanadium weight percent, were studied in detail. The outcomes reveal that V @ NiO samples have photocatalytic activity higher than that of NiO samples due to their ability to hinder the electron–hole recombination rate and decrease the band gap energy.

An investigation of a nonspiking Ohmic contact to n-GaAs using the Si/Pd system

1988 ◽  
Vol 3 (5) ◽  
pp. 922-930 ◽  
Author(s):  
L. C. Wang ◽  
B. Zhang ◽  
F. Fang ◽  
E. D. Marshall ◽  
S. S. Lau ◽  
...  
Keyword(s):  
Ohmic Contact ◽  
Rutherford Backscattering Spectrometry ◽  
Tunneling Current ◽  
Solid State Reactions ◽  
Cross Sectional ◽  
Ohmic Behavior ◽  
Transmission Electron ◽  
Specific Contact ◽  
Diffraction Patterns ◽  
Ohmic Contact Formation

A low-resistance nonspiking Ohmic contact to n-GaAs is formed via solid-state reactions utilizing the Si/Pd/GaAs system. Samples with Si to Pd atomic ratios greater than 0.65 result in specific contact resistivity of the order of 10−6 Ω cm2, whereas samples with atomic ratios less than 0.65 yield higher specific contact resistivities or rectifying contacts. Rutherford backscattering spectrometry, cross-sectional transmission electron microscopy, and electron diffraction patterns show that a Pd, Si layer is in contact with GaAs with excess Si on the surface after the Ohmic formation annealing. This observation contrasts with that on a previously studied Ge/Pd/GaAs contact where Ohmic behavior is detected after transport of Ge through PdGe to the interface with GaAs. Comparing the Ge/Pd/GaAs system with the present Si/Pd/GaAs system suggests that a low barrier heterojunction between Ge and GaAs is not the primary reason for Ohmic contact behavior. Low-temperature measurements suggest that Ohmic behavior results from tunneling current transport mechanisms. A regrowth mechanism involving the formation of an n+ GaAs surface layer is proposed to explain the Ohmic contact formation.

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