scholarly journals Dielectric properties of Bi-substituted LDHs synthesized by co-precipitation and sol-gel methods

2019 ◽  
Vol 37 (2) ◽  
pp. 190-195 ◽  
Author(s):  
Denis Sokol ◽  
Maksim Ivanov ◽  
Andrei N. Salak ◽  
Robertas Grigalaitis ◽  
Juras Banys ◽  
...  
Keyword(s):  
Sol Gel ◽  
Xrd Analysis ◽  
Precipitation Method ◽  
Complexing Agent ◽  
Mixed Metal Oxides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
Double Hydroxides ◽  
Gel Processing

AbstractMagnesium-aluminum-bismuth layered double hydroxides (Mg3Al1−xBix; LDHs) were prepared using both coprecipitation and sol-gel methods. For the preparation of Mg/Al/Bi LDH by the co-precipitation method, the appropriate amounts of dissolved starting materials (Al(NO3)3 · 9H2O, Mg(NO3)2 · 6H2O and Bi(NO3)3 · 5H2O) were mixed with a solution of NaHCO3:NaOH. In the sol-gel processing, the precursor Mg–Al–Bi–O gels were synthesized using the same starting materials and ethylene glycol as complexing agent. The mixed-metal oxides obtained by subsequent heating of Mg–Al–Bi–O gels at 650 °C were reconstructed to Mg3Al1−xBix LDHs in water at 80 °C. All the synthesized products were characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and dielectric measurements.

Synthesis of Nano-Sized SrTiO3 Photocatalyst by Sol-Gel Method

2012 ◽  
Vol 512-515 ◽  
pp. 1673-1676 ◽  
Author(s):  
Wei Zhao ◽  
Jian Jun Yao ◽  
Jing Ya ◽  
Lei E ◽  
Zhi Feng Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Complexing Agent ◽  
Strontium Nitrate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ph Values ◽  
Gel Processing

A sol-gel processing technology was employed to synthesize fine SrTiO3 powder by using strontium nitrate (Sr(NO3)2) , butyl titanate (Ti(OC4H9)4) as precursors, citric acid (C6H8O6) as complexing agent and (ethylene) glycol (C2H6O2) as stabilizer. Prepared the precursors in liquid phase and then calcined the precursors to achieve nano-sized SrTiO3 powders. The microstructure and composition of the as-synthesized samples were characterized by X-ray diffraction (XRD), Scan Electron Microscopy (SEM), and the photocatalytic activity was studied. The results showed that all the SrTiO3 particles were identified as perovskite phase. The pH values, the content of the acetic acid, the heat treat temperature play important roles on the synthesis of the SrTiO3 photocatalyst. When the pH=1, n(Sr(NO3)2 ) : n(Ti(OC4H9)4) = 1 : 1, n(Sr(NO3)2 ) : n(C6H8O6)=1:1.7, the product has better rate of photodegradation for the Methylene Blue under the ultraviolet condition.

scholarly journals Undoped and Eu3+ Doped Magnesium-Aluminium Layered Double Hydroxides: Peculiarities of Intercalation of Organic Anions and Investigation of Luminescence Properties

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 736 ◽  
Author(s):  
Aurelija Smalenskaite ◽  
Lina Pavasaryte ◽  
Thomas Yang ◽  
Aivaras Kareiva
Keyword(s):  
Layered Double Hydroxides ◽  
Organic Anion ◽  
Sol Gel ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Organic Guests ◽  
Double Hydroxides ◽  
Scanning Electron

The Mg3/Al and Mg3/Al0.99Eu0.01 layered double hydroxides (LDHs) were fabricated using a sol-gel chemistry approach and intercalated with different anions through ion exchange procedure. The influence of the origin of organic anion (oxalate, laurate, malonate, succinate, tartrate, benzoate, 1,3,5-benzentricarboxylate (BTC), 4-methylbenzoate (MB), 4-dimethylaminobenzoate (DMB) and 4-biphenylacetonate (BPhAc)) on the evolution of the chemical composition of the inorganic-organic LDHs system has been investigated. The obtained results indicated that the type and arrangement of organic guests between layers of the LDHs influence Eu3+ luminescence in the synthesized different hybrid inorganic–organic matrixes. For the characterization of synthesis products X-ray diffraction (XRD) analysis, infrared (FTIR) spectroscopy, fluorescence spectroscopy (FLS), and scanning electron microscopy (SEM), were used.

Dielectric and Ferroelectric Properties of Modified BiFeO3-PbTiO3 Thin Films Derived from Sol-gel Processing

2003 ◽  
Vol 784 ◽  
Author(s):  
JinRong Cheng ◽  
L. Eric Cross
Keyword(s):  
Thin Films ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Gel Processing ◽  
Room Temperature Dielectric Constant

ABSTRACTIn this paper, thin films of La- modified (Bi,La)FeO3-PbTiO3 (BLF-PT) morphotropic phase boundary (MPB) solid solutions have been prepared by using sol-gel processing. A thin Pb(Zr,Ti)O3 (PZT) template layer was introduced to make BLF-PT thin films adhere tightly to the platinized silicon (Pt/Ti/SiO2/Si) substrate. X-ray diffraction (XRD) analysis revealed that BLF-PT thin films were of the perovskite structure without detectable pyrochlore phase annealing at 650–750°C. The cross sectional and plain view images of or our specimen were observed by using the scan electrical microscope (SEM). The room temperature dielectric constant K and tanδ were of ∼800 and 4% respectively, for BLF-PT thin films using a measurement frequency of 1 kHz. Our preliminary experiments indicated that the sol-gel derived BLF-PT thin films have good insulation resistance and measurable dielectric and ferroelectric responses.

scholarly journals Method for preventing air pollution: Methane oxidation by two types of catalysts

2014 ◽  
Vol 25 (1) ◽  
pp. 43-46
Author(s):  
Cristina Ileana Covaliu ◽  
Gina Alina Traistaru ◽  
Gigel Paraschiv
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Air Pollution ◽  
Methane Oxidation ◽  
Sol Gel ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
Scanning Electron

Abstract Methane oxidation using different catalysts is an useful process for preventing air pollution. This study presents the methane oxidation by two types of catalysts: Pd-Sn/Al2O3 and spinel mixed oxide, CuFe2O4. The Pd-Sn/Al2O3 was successfully prepared by sol-gel method and CuFe2O4 by co-precipitation method. The catalysts obtained have been characterized structurally, morphologically and texturally by X-ray diffraction (XRD), scanning electron microscopy (SEM) and specific surface area (BET). The catalytic activity tests regarding methane oxidation were also performed.

scholarly journals Syntheses and Thermal Characterisation of Mixed (Sm-Y) Oxalates Prepared by Coprecipitation Method

2011 ◽  
Vol 8 (1) ◽  
pp. 113-117
Author(s):  
Presenjit Pauri ◽  
S. K. Ghoshal ◽  
H. S. Tewari
Keyword(s):  
Solid Solution ◽  
Thermal Decomposition ◽  
Thermal Treatment ◽  
Differential Scanning Calorimeter ◽  
Mixed Oxides ◽  
Xrd Analysis ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation

In this work, mixed (Sm1-xYx)2[C2O4]3.nH2O with x= 0.50 and 0.70 were prepared using standardized co precipitation method. All the synthesized oxalates were characterized by x-ray diffraction and differential scanning calorimeter. All the samples are homogeneous in stoichiometry. The XRD analysis of these synthesized samples reveals that a solid solution forms for these two compositions The thermal decomposition of the mixed oxalates is complex although completed a lower temperatures. This is an important result for the preparation of Sm-Y mixed oxides, because all the properties of the mixed oxides are intrinsic and depend only on their composition and thermal treatment schedules.

Synthesis and Characterization of Ni/Mg/Al Mixed Oxides Obtained by Co-precipitation

2012 ◽  
Vol 1372 ◽  
Author(s):  
G. Martínez-Lozano ◽  
T. Kryshtab ◽  
M. Hesiquio Garduño ◽  
A. Kryvko
Keyword(s):  
Mixed Oxides ◽  
Xrd Analysis ◽  
Diffraction Peak ◽  
Precipitation Method ◽  
Particle Sizes ◽  
Extended Defects ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation

ABSTRACTNi/Mg/Al mixed oxides were obtained from hydrotalcite-like precursors by thermal decomposition at 400º, 600º and 800ºC using co-precipitation method at pH 7. The mixed oxides were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), and Energy-dispersive X-ray spectroscopy (EDS) techniques. XRD analysis revealed the formation of NixMg1-xO (x = 0 - 1), α-Al2O3 and traces of MgAl2O4 (NiAl2O4) phases. The diffraction peak positions for MgO or NiO oxides were shifted towards 2θ values higher than simulated for pure bulk oxides that can be attributed to the possible presence of lattice vacancies or surface compressive stress. The evaluated grain size by XRD technique was about 8 -10 nm. It was also detected the presence of microstrains that can be associated with the presence of extended defects in the grains. SEM observations showed that the particles of oxides are formed as agglomerates with the particle sizes of 50 nm up to 200 nm. EDS detected the presence of Mg2+, Ni2+, and Al3+ cations and oxygen in all particles independently on their size. The obtained results revealed the presence of mixture of Ni/Mg/Al oxides in each particle obtained. The oxides calcined at temperatures of 400º and 600ºC were unstable and under air storage they revert to the precursor. The incorporation of Ni2+ in Mg-Al mixed oxides leads to stability of the compounds calcined at 800ºC.

scholarly journals Removal of Iron(II) Using Intercalated Ca/Al Layered Double Hydroxides with [α-SiW12O40]4-

2019 ◽  
Vol 14 (2) ◽  
pp. 260 ◽  
Author(s):  
Tarmizi Taher ◽  
Mikha Meilinda Christina ◽  
Muhammad Said ◽  
Nurlisa Hidayati ◽  
Ferlinahayati Ferlinahayati ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Layer Structure ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Co Precipitation ◽  
Double Hydroxide ◽  
Double Hydroxides ◽  
Synthesized Materials

Ca/Al layered double hydroxide (LDH) was successfully synthesized by co-precipitation method at pH 11 under room temperature condition then followed by calcination at 800 oC. The synthesized Ca/Al LDH was further intercalated with Keggin ion [α-SiW12O40]4- in order to prepare the intercalated form of Ca/Al LDH. The synthesized materials were characterized by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) and used as an adsorbent for iron(II) removal from the aqueous medium. The adsorption performance was investigated by studying the kinetics and thermodynamic properties of the adsorption process. The results showed that pristine Ca/Al LDH exhibited diffraction peak at 2θ about 20o which corresponds to the layer structure of the LDH material. For the intercalated Ca/Al LDH, the diffraction observed at 2θ around 30-40o indicated that the [α-SiW12O40]4- was successfully intercalated into the interlayer space of Ca/Al LDH. Furthermore, the intercalated Ca/Al LDH showed higher adsorption capacity toward iron(II) than the pristine form of Ca/Al LDH. Copyright © 2019 BCREC Group. All rights reserved 

Preparation, characterization and antibacterial applications of ZnAl- LDH with the diaminododecylphosphonic acid intercalation

2021 ◽  
Vol 11 (5) ◽  
pp. 600-604
Author(s):  
Ziani Hanane ◽  
M’hamed Kaid ◽  
Ikhou Djamila ◽  
Abdelkader Ammam ◽  
D. Villemin
Keyword(s):  
Phosphonic Acid ◽  
Antibacterial Activities ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range ◽  
Bet Analysis ◽  
Co Precipitation ◽  
Double Hydroxides ◽  
Health Applications

Layered double hydroxides (LDHs) have been widely investigated in a wide range of applications in health, in the pharmaceutical industry and in the material of biotechnology industries. This material can be considered as a group of promising materials in the development of new health applications. The combination of phosphonic acid with LDHs material create a new hybrid material with new properties.In this work the synthesis of Zn/Al double lay-ered hydroxides by chemical co-precipitation method (molar ration 2) and grafted with Diamino Dodecyl Phosphonic Acid (DDPA) via anion-exchange mechanism. The samples were characterized and confirmed by X-ray diffraction (XRD), and the presence of diamino dodecyl phosphonic acid (DDPA ) was verified by Elemental analysis, BET analysis, and infrared spec-troscopy. Both of the samples were found to be showing antibacterial activ-ity. The zone diameters of Zn-Al- LDH were 40 mm and 25 mm for Esche-richia coli(ATCC 25922) and Streptococcus (ATCC 25922)and 20 mm for bacillus (ATCC 25922) whereas the same for hybrid LDH (Zn-Al-DDPA)were43 mm , 32 mm and 25 mm for the same bacteria showing stronger antibacterial activity of the grafted material over the material itself. The experimental results confirm the application of Zn-Al-DDPA in the field of antibacterial activities and may offer a promising antibacterial elucidation to the society.

scholarly journals Photoluminescent Properties of Hydroxyapatite and Hydroxyapatite/Multi-Walled Carbon Nanotube Composites

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 832
Author(s):  
Edna X. Figueroa-Rosales ◽  
Javier Martínez-Juárez ◽  
Esmeralda García-Díaz ◽  
Daniel Hernández-Cruz ◽  
Sergio A. Sabinas-Hernández ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Hexagonal Phase ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multi Walled Carbon Nanotube ◽  
Nanotube Composites ◽  
Carbon Nanotube Composites ◽  
Co Precipitation ◽  
Functionalized Mwcnts

Hydroxyapatite (HAp) and hydroxyapatite/multi-walled carbon nanotube (MWCNT) composites were obtained by the co-precipitation method, followed by ultrasound-assisted and microwave radiation and thermal treatment at 250 °C. X-ray diffraction (XRD) confirmed the presence of a hexagonal phase in all the samples, while Fourier-transform infrared (FTIR) spectroscopy elucidated the interaction between HAp and MWCNTs. The photoluminescent technique revealed that HAp and the composite with non-functionalized MWCNTs present a blue luminescence, while the composite with functionalized MWCNTs, under UV-vis radiation shows an intense white emission. These findings allowed presentation of a proposal for the use of HAp and HAp with functionalized MWCNTs as potential materials for optoelectronic and medical applications.

Photocatalytic Activity of Fe-Doped ZnO/Montmorillonite Nanocomposite for Degradation of Malachite Green

2015 ◽  
Vol 827 ◽  
pp. 19-24 ◽  
Author(s):  
Nur Afifah ◽  
Nadia Febiana Djaja ◽  
Rosari Saleh
Keyword(s):  
Photocatalytic Activity ◽  
Malachite Green ◽  
Organic Dyes ◽  
Uv Light ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spin Resonance ◽  
Doped Zno ◽  
Co Precipitation

In this study, the photocatalytic activity of pure Fe- doped ZnO and Fe- doped ZnO/Montmorillonite nanocomposite has been investigated for the degradation of malachite green under UV light irradiation. Both photocatalysts were synthesized using co-precipitation method and characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, Fourier-transform infrared absorption, and electron spin resonance. The results showed that the photocatalytic efficiency is better in the presence of montmorillonite compared to pure Fe- doped ZnO. To detect the possible reactive species involved in degradation of organic dyes control experiments with introducing scavengers into the solution of organic dyes were carried out. It is found that electron plays an important role in the degradation of malachite green.

Sign in / Sign up

Export Citation Format

Share Document