scholarly journals Synthesis and Characterization of K-Ta Mixed Oxides for Hydrogen Generation in Photocatalysis

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Beata Zielińska ◽  
Ewa Mijowska ◽  
Ryszard J. Kalenczuk
Keyword(s):  
Diffuse Reflectance ◽  
Hydrogen Generation ◽  
Mixed Oxides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Raman Spectroscopic ◽  
Photocatalytic Hydrogen Generation ◽  
Irregular Structure ◽  
Transmission Electron

K-Ta mixed oxides photocatalysts have been prepared by impregnation followed by calcination. The influence of the reaction temperature (450°C–900°C) on the phase formation, crystal morphology, and photocatalytic activity in hydrogen generation of the produced materials was investigated. The detailed analysis has revealed that all products exhibit high crystallinity and irregular structure. Moreover, two different crystal structures of potassium tantalates such as KTaO3and K2Ta4O11were obtained. It was also found that the sample composed of KTaO3and traces of unreacted Ta2O5(annealed at 600°C) exhibits the highest activity in the reaction of photocatalytic hydrogen generation. The crystallographic phases, optical and vibronic properties were examined by X-ray diffraction (XRD) and diffuse reflectance (DR) UV-vis and resonance Raman spectroscopic methods, respectively. Morphology and chemical composition of the produced samples were studied using a high-resolution transmission electron microscope (HR-TEM) and an energy dispersive X-ray spectrometer (EDX) as its mode.

Synthesis and Characterization of Lead Sulfide Nanostructures with Different Morphologies via Simple Hydrothermal Method

2016 ◽  
Vol 35 (6) ◽  
pp. 559-566 ◽  
Author(s):  
Elaheh Esmaeili ◽  
Mohammad Sabet ◽  
Masoud Salavati-Niasari ◽  
Kamal Saberyan
Keyword(s):  
Electron Microscopy ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
Product Size ◽  
X Ray ◽  
Transmission Electron ◽  
Hydrothermal Approach ◽  
Size And Morphology

AbstractPbS nanostructures were synthesized successfully via hydrothermal approach with a new precursor. The products were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV–Vis diffuse reflectance spectroscopy (DRS). The effect of different sulfur sources were investigated on product size and morphology.

scholarly journals Preparation, characterization and photocatalytic activity of Co3O4/LiNbO3 composite

2013 ◽  
Vol 11 (6) ◽  
pp. 920-926 ◽  
Author(s):  
Beata Zielinska ◽  
Magdalena Janus ◽  
Ryszard Kalenczuk
Keyword(s):  
Photocatalytic Activity ◽  
Hydrogen Generation ◽  
Cobalt Content ◽  
Cobalt Nitrate ◽  
Spectroscopic Techniques ◽  
X Ray Diffraction ◽  
X Ray ◽  
Raman Spectroscopic ◽  
Photocatalytic Hydrogen Generation ◽  
Content Range

AbstractThe Co3O4/LiNbO3 composites were synthesized by impregnation of LiNbO3 in an aqueous solution of cobalt nitrate and next by calcination at 400°C. The activity of produced samples has been investigated in the reaction of photocatalytic hydrogen generation. The crystallographic phases, optical and vibronic properties were studied using X-ray diffraction (XRD), diffuse reflectance (DR) UV-vis and resonance Raman spectroscopic techniques, respectively. The influence of cobalt content (range from 0.5 wt.% to 4 wt.%) on the photocatalytic activity of Co3O4/LiNbO3 composites for photocatalytic hydrogen generation has been investigated. Co3O4/LiNbO3 composites exhibited higher than LiNbO3 photocatalytic activity for hydrogen generation. The highest H2 evolution efficiency was observed for Co3O4/LiNbO3 composite with 3 wt.% cobalt content. The amount of H2 obtained in the presence of LiNbO3 and Co3O4/LiNbO3 (3 wt.% of cobalt content) was 1.38 µmol/min and 2.59 µmol min−1, respectively.

Synthesis and Characterization of Tantalum Based Photocatalysts and Application for Methylene Blue Degradation

2016 ◽  
Vol 855 ◽  
pp. 147-155
Author(s):  
Meghshyam K. Patil ◽  
Hari C. Bajaj ◽  
Rajesh J. Tayade
Keyword(s):  
Methylene Blue ◽  
Diffuse Reflectance ◽  
Mixed Oxides ◽  
Diffuse Reflectance Spectroscopy ◽  
Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
Methylene Blue Degradation ◽  
Degradation Study ◽  
X Ray

Ta2O5, Ta2O5–SrO and Ta2O5–TiO2 photocatalysts were prepared by hydrothermal method and characterized using X-ray diffraction (XRD), Ultraviolet-visible Diffuse Reflectance spectroscopy (UV-Vis DRS) and Thermogravimetry (TGA). In synthesized series of TiO2-Ta2O5 catalysts, formation of anatase TiO2, hexagonal Ta2O5 and titanium tantalates were observed. For Ta2O5-SrO (Ta:Sr= 1:1) formation of mixed oxide and crystallinity was observed at calcinations temperature at 1100 °C (5hr). These synthesized catalysts were used for degradation study of methylene blue. The result demonstrated that the photocatalytic activity of the mixed oxides [Ta2O5-TiO2(1:1), Ta2O5-TiO2(2:1), Ta2O5-TiO2(1:2), Ta2O5-SrO (Ta:Sr= 1:1)] was higher than that of Ta2O5 alone.

Synthesis and Characterization of Cu2O/TNTs Nanocomposites

2009 ◽  
Vol 79-82 ◽  
pp. 601-604
Author(s):  
Hui Liu ◽  
Li Ang Song ◽  
Wei Liu ◽  
Ge Su ◽  
Li Xin Cao ◽  
...  
Keyword(s):  
Diffuse Reflectance ◽  
Reflectance Spectra ◽  
Synthesis And Characterization ◽  
Visible Light Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffuse Reflectance Spectra ◽  
Transmission Electron ◽  
Light Region

Cu2O/TNTs(Titanium-based Nanotubes) composites were prepared by a simple “soak-deoxidize” method by using hydrazine hydrate as the reducing agent. The Cu2O/TNTs composites particles was made by changing pH and the mol ratio of Cu2+:N2H4H2O. The obtained composites were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), UV-Vis Diffuse reflectance spectra(DRS). The results of UV-Vis diffuse reflectance spectra indicate that the absorption edge of Cu2O/TNTs shows a shift to visible-light region, followed by an obvious absorption peak at 500–700 nm.

scholarly journals Structural, Optical and Photocatalytic Activity of The Cerium Doped Ba2TiMoO6 Double Perovskite.

2021 ◽  
Author(s):  
Taher Ghrib ◽  
Athaa Al-Otaibi ◽  
Qasim Mahmoud ◽  
Filiz Ercan ◽  
Asghar Ali ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Diffuse Reflectance ◽  
Double Perovskite ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Violet Emission ◽  
X Ray ◽  
Transmission Electron ◽  
Synthesis Strategy

Abstract In this work, it was highlighted synthesis strategy and fundamental characterization of the pure and Ce doped Ba2TiMoO6 with different Ce concentrations were presented. It was investigated its thermal stability by using the Thermal Gravimetric Analysis and Differential Thermal Analysis. The crystal structures and the purity of the compounds were analyzed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The Surface morphology was examined by using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and surface area analysis. The optical properties were examined by using the UV-Vis diffuse reflectance and photoluminescence (PL) spectroscopies. The prepared Ba2TiMoO6 nanopowders are characterized by band gap of 3.41~3.6 eV and violet emission of 426.67 nm wavelength. The degradation efficiency was found approximately 16% of Methyl Blue (MO) after 120 min duration. Our results will predicate new Perovskites materials, which can be used for future environmental applications.

scholarly journals Synthesis and Photocatalytic Activity of ZnO/H3PW12O40-Supported Mordenite Composite

2010 ◽  
Vol 19 (5) ◽  
pp. 096369351001900
Author(s):  
Lingling Wang ◽  
Miaoling Huang ◽  
Xiaolan Xie
Keyword(s):  
Photocatalytic Activity ◽  
Diffuse Reflectance ◽  
Energy Dispersive Spectrometer ◽  
Fold Increase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Photodegradation Rate ◽  
Transmission Electron ◽  
Rate Versus

12-tungstophosphoric acid (H3PW12O40) and Zinc oxide (ZnO) particles were encapsulated into mordenite by salt melting procedure. The material was characterized by X-ray diffraction (XRD), Ultraviolet-visible diffuse reflectance spectra (UV-Vis-DRS), High Resolution Transmission Electron Microscopy (HRTEM), Energy Dispersive Spectrometer (EDS), and Brunauer, Emmett and Teller surface area (BET). The characterization of ZnO/H3PW12O40-supported mordenite composite (ZnO/PW12/mordenite) clearly shows that some of ZnO and H3PW12O40 particles were encapsulated within the cavities and frameworks of mordenite, which effectively increases the photocatalytic activity on degradation of methyl orange. The ZnO/PW12/mordenite composite showed 1.7-fold increase amplitude of the photodegradation rate versus that of ZnO-supported mordenite composite (ZnO/mordenite) without H3PW12O40.

Preparation and characterization of mesoporous ceria–zirconia–alumina nanocomposite with high hydrothermal stability

2007 ◽  
Vol 22 (11) ◽  
pp. 3201-3209 ◽  
Author(s):  
Md. Hasan Zahir ◽  
Yumi H. Ikuhara ◽  
Shinji Fujisaki ◽  
Koji Sato ◽  
Takayuki Nagano ◽  
...  
Keyword(s):  
Mixed Oxides ◽  
Sol Gel ◽  
Ternary Systems ◽  
Steam Treatment ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Raman Spectroscopic ◽  
Transmission Electron ◽  
Before And After

CeO2–ZrO2–γ-Al2O3 mixed oxides with different molar compositions have been synthesized by the sol-gel method using nitrate–alkoxide precursors. Some relationships between the molar composition of the ternary systems and their textural and structural properties are presented. CeO2–ZrO2–γ-Al2O3 mixed oxides have been studied and characterized using x-ray diffraction, transmission electron microscopy, and Raman spectroscopic analyses. By complete porosity analyses of all samples before and after hydrothermal (up to 75% steam) treatment at 500 °C, we have been able to optimize a highly hydrothermally stable CeO2–ZrO2–γ-Al2O3 system with a molar ratio of 10:10:80 mol%. γ-Al2O3 alone and CeO2-doped as well as ZrO2-doped γ-Al2O3 were also investigated by the hydrothermal treatment, and their steam-sensitive properties have been compared with those of the ternary CeO2–ZrO2–γ-Al2O3 system.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Detonation Synthesis of Nano-Size Materials

1995 ◽  
Vol 418 ◽  
Author(s):  
J. Forbes ◽  
J. Davis ◽  
C. Wong
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nucleation And Growth ◽  
Detonation Synthesis ◽  
X Ray Diffraction ◽  
Crystalline Materials ◽  
X Ray ◽  
Transmission Electron ◽  
Nano Size

AbstractThe detonation of explosives typically creates 100's of kbar pressures and 1000's K temperatures. These pressures and temperatures last for only a fraction of a microsecond as the products expand. Nucleation and growth of crystalline materials can occur under these conditions. Recovery of these materials is difficult but can occur in some circumstances. This paper describes the detonation synthesis facility, recovery of nano-size diamond, and plans to synthesize other nano-size materials by modifying the chemical composition of explosive compounds. The characterization of nano-size diamonds by transmission electron microscopy and electron diffraction, X-ray diffraction and Raman spectroscopy will also be reported.

One Step Synthesis and Characterization of Zirconia-Graphene Composites

2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
Author(s):  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
Fu Qiang Zhu ◽  
...  
Keyword(s):  
Synthesis And Characterization ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Composite ◽  
Transmission Electron ◽  
One Step ◽  
Ft Ir ◽  
Xrd Techniques

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.

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