Preparation and Morphological Controlling of Nanophase NaNbO3 by Sol-Gel Method

2008 ◽  
Vol 368-372 ◽  
pp. 140-143 ◽  
Author(s):  
Ying Lin ◽  
Hai Bo Yang ◽  
Fen Wang
Keyword(s):  
Metal Ion ◽  
Ph Value ◽  
Sol Gel ◽  
Chelating Agent ◽  
Gel Method ◽  
Sol Gel Method ◽  
Forming Mechanism ◽  
Water As Solvent ◽  
Rapid Temperature ◽  
The Stability

With citric acid as chelating agent, ethylene alcohol as etherification agent and water as solvent, NaNbO3 nanopowder was synthesized by citrate sol-gel method. The effects of amount of CA and EG, pH value on the stability of the precursor sol were investigated. The evolution of NaNbO3 crystal phase was also investigated by XRD and TG-DTA. The results showed that a homogeneous precursor sol was formed at in the case of n(CA) : n(metal ion)=3:1, n(CA) : n(EG)=1: 2 and 1:3 and pH=7.5. Sintering process largely influences the morphology of the prepared products. Grain-like nanoparticles could be obtained with a rapid temperature rising rate, while nanorods were obtained with a slow rate. The forming mechanism of different morphologies of the prepared nanoparticles was also discussed.

LiMn2O4 nanopowders synthesized via gelatin-assisted sol–gel method: Optimization of pH and calcination temperature

2019 ◽  
Vol 33 (08) ◽  
pp. 1950063
Author(s):  
Nasrin Azad ◽  
Hadi Arabi ◽  
Shaban Reza Ghorbani ◽  
Ali Davodi
Keyword(s):  
Calcination Temperature ◽  
Ph Value ◽  
Sol Gel ◽  
Chelating Agent ◽  
The Other ◽  
Effect Of Temperature ◽  
Gel Method ◽  
Sol Gel Method ◽  
The Fourier Transform ◽  
The Stability

In this research, LiMn2O4 nanopowders were synthesized via sol–gel method using gelatin as a novel chelating agent. The effect of temperature and pH on the structure, morphology and particle size of synthesized powders has been investigated by the differential thermal analysis (DTA), the X-ray diffraction (XRD), the Fourier transform infrared (FTIR) and the field-emission scanning electron microscope (FESEM). The crystal structure of LiMn2O4 was completely formed without any impurity phase at a calcination temperature of 750[Formula: see text]C. The peak intensity ratio of I[Formula: see text]/I[Formula: see text], which presents the stability of LiMn2O4 structure, is bigger for the sample with pH[Formula: see text]=[Formula: see text]4 than that of the samples with pH[Formula: see text]=[Formula: see text]7 and 8. The sample with pH[Formula: see text]=[Formula: see text]4 has smaller particles of about 70 nm, with more homogeneity and less agglomeration than that of the other samples. At calcination temperature to 850[Formula: see text]C, the size of the particles has become bigger and the particle surfaces show more clarity in all samples. The effect of the pH value on electrochemical properties was studied by galvanostatic charge/discharge tests. The results show more capacity lost for the sample with pH[Formula: see text]=[Formula: see text]8 with regards to the other samples.

scholarly journals Effect of pH and annealing temperature on the structural and magnetic properties of cerium-substituted yttrium iron garnet powders produced by the sol-gel method

2016 ◽  
Vol 34 (2) ◽  
pp. 362-367 ◽  
Author(s):  
I. Yarici ◽  
M. Erol ◽  
E. Celik ◽  
Y. Ozturk
Keyword(s):  
Magnetic Properties ◽  
Yttrium Iron Garnet ◽  
Annealing Temperature ◽  
Ph Value ◽  
Sol Gel ◽  
Chelating Agent ◽  
Yttrium Iron ◽  
Gel Method ◽  
Sol Gel Method ◽  
Iron Garnet

AbstractCerium substituted yttrium iron garnet (Ce0.2Y2.8Fe5O12; Ce-YIG) nanoparticles were produced via the sol-gel method from solutions of Ce-, Y- and Fe-based precursors, a solvent and a chelating agent. The solutions were dried at 200°C and heat treated at temperatures between 800 °C and 1400°C for 3 h in air. The effects of pH and annealing temperature on the structure, phase formation, magnetic properties and crystallite size were investigated. A cubic YIG phase was obtained for the sample annealed at 1400 °C. The presented results showed that the pH value of the starting solution affects the crystal size and consequently, the saturation magnetization.

Optimization of Experimental Parameters to the Formation of Bi2212 Phase via Sol-Gel Method

2011 ◽  
Vol 328-330 ◽  
pp. 1499-1502
Author(s):  
Hua Zhe Yang ◽  
Ye Song He ◽  
Yang Ji ◽  
Zi Mu Li ◽  
Hao Zhu
Keyword(s):  
Sol Gel ◽  
Precursor Solution ◽  
Chelating Agent ◽  
Solution Concentration ◽  
Treatment Temperature ◽  
Gel Method ◽  
Sol Gel Method ◽  
Metal Nitrates ◽  
Water As Solvent ◽  
Experimental Parameters

Bi-2212 superconducting phase was synthesized via sol-gel method, and the experimental parameters such as the concentration of precursor solution and heat treatment temperature were adjusted to find the optimal conditions. Metal nitrates were adopted as the starting materials and ethylenediaminetetracetic acid (EDTA) as chelating agent. Precursor solutions and gel with different concentration were obtained through the addition of different content of distilled water as solvent followed by heating at certain temperature to form grey powders. Afterwards, the powders were sintered at different temperature for 10 hours, respectively. X-ray diffraction (XRD) was adopted to investigate the phase purity and crystallinity of the sample derived. Results reveal that the optimized precursor solution concentration is 27% and the optimized sintering temperature is 850°C.

Synthesis and characterization of macroporous europium-doped Ca12Al14O33 (C12A7:Eu3+) and its application in metal ion detection

2019 ◽  
Vol 43 (21) ◽  
pp. 8315-8324
Author(s):  
Hui Yang ◽  
Rui Wang ◽  
Yaozu Wang ◽  
Jianzhong Jiang ◽  
Xingzhong Guo
Keyword(s):  
Heat Treatment ◽  
Metal Ion ◽  
Sol Gel ◽  
Synthesis And Characterization ◽  
Practical Application ◽  
Ion Detection ◽  
Gel Method ◽  
Sol Gel Method ◽  
Metal Ion Detection

Macroporous europium-doped Ca12Al14O33 (C12A7:Eu3+) was prepared via a sol–gel method followed by heat-treatment, and the resultant macroporous C12A7:Eu3+ shows potential for practical application in metal ion detection and has a good response to Pb2+ ions.

The Research on ODS Iron Powder by Sol-Gel Method

2012 ◽  
Vol 476-478 ◽  
pp. 1146-1149 ◽  
Author(s):  
Xiao Yu ◽  
Zhi Meng Guo ◽  
Jun Jie Hao ◽  
Wei Wei Yang
Keyword(s):  
Mechanical Alloying ◽  
Iron Powder ◽  
Ferritic Steel ◽  
Ph Value ◽  
Sol Gel ◽  
Oxide Dispersion Strengthened ◽  
Steel Powder ◽  
Raw Material ◽  
Gel Method ◽  
Sol Gel Method

Oxide dispersion strengthened (ODS) ferritic steel which contains Y2O3 dispersion is one of the most promising candidates for fast neutron reactor cladding materials due to its excellent swelling resistance to neutron and superior creep resistance in high temperature. There are many ways to prepare ODS ferritic steel and the most commonly used method is mechanical alloying. However, ODS ferritic steel produced by the method of mechanical alloying is poor in the plasticity and impact property. Moreover, the anisotropies of structure and properties are obvious in the follow-up processing. In this paper, in order to reduce the cost, iron powder is used as raw material instead of ferritic steel powder. The complexing sol-gel method is adopted to prepare ODS iron-powder. There are many advantages of the sol-gel method such as the small size of disperse phase and the high uniformity. Besides, it is easy to control the conditions of reaction such as the water content, the bath temperature and the PH value. The gel-coated iron powder can be prepared under the appropriate environmental conditions. Then, we can obtain iron powder with Y2O3 dispersion after heating and reducing the gel-coated iron powder. By the spark plasma sintering(SPS), the ODS iron powder can be densified and we can observe the microstructure and test the performance. The results reveal the Y2O3 dispersion of ODS iron-powder by sol-gel method is uniform and the mechanical property is excellent.

Fabrication of Bi-2223 Powders Using Sol-Gel Method

2011 ◽  
Vol 412 ◽  
pp. 125-128 ◽  
Author(s):  
Ming Ya Li ◽  
Xiao Yan Wang ◽  
Cheng Li Ye ◽  
Feng Lin Xue
Keyword(s):  
Heat Treatment ◽  
Sol Gel ◽  
Chelating Agent ◽  
Experimental Results ◽  
Main Phase ◽  
Gel Method ◽  
Sol Gel Method ◽  
Dwelling Time ◽  
Metal Nitrates ◽  
Gel Technique

The Bi-2223 powders were fabricated by the sol-gel technique. Metal nitrates were used as starting materials, and ethylenediamineteracetic acid was used as chelating agent. The solution was heated until it turns to gel. Then the organic was removed at a temperature of 240°C, and the nitrite was removed at 500°C. The powder was calcined at different temperature, varying the dwelling time. Experimental results show that the main phase of samples after heat treatment is Bi-2212 phase.

DIFFERENT MORPHOLOGIES OFTiO2NANOSTRUCTURES IN ACIDIC AND BASIC SOL–GEL METHOD

NANO ◽  
2010 ◽  
Vol 05 (05) ◽  
pp. 279-285 ◽  
Author(s):  
M. H. IMANIEH ◽  
Y. VAHIDSHAD ◽  
P. NOURPOUR ◽  
S. SHAKESI ◽  
K. SHABANI
Keyword(s):  
Ph Value ◽  
Sol Gel ◽  
Simple Method ◽  
Gel Method ◽  
Sol Gel Method ◽  
New Process ◽  
Nanocrystalline Titanium ◽  
Acidic Conditions ◽  
Nanocrystalline Titanium Dioxide ◽  
First Time

In this research, nanocrystalline titanium dioxide (TiO2) particles were prepared by a modified alkoxide technique under basic and acidic conditions at room temperatures. A simple method for preparing different morphology of TiO2has been developed. The reaction condition was used to control the crystalline size, phase and morphology of the TiO2nanostructures. In this process by adjusting the Rw(water to precursor ratio) and pH value the hydrolysis and condensation reactions were controlled. This led to the development of a new process to produce TiO2nanorod (for the first time by sol–gel method) at high pH value (basic) while the water content was sufficient whereas at low pH value (acidic) nanosphere TiO2were obtained. The powders were characterized by DTA, XRD, FE-SEM and UV–vis techniques and their physical properties were compared.

Synthesis, structural, magnetic and electrochemical properties of LiNi1/3Mn1/3Co1/3O2 prepared by a sol–gel method using table sugar as chelating agent

2013 ◽  
Vol 113 ◽  
pp. 313-321 ◽  
Author(s):  
Nilüfer Kızıltaş-Yavuz ◽  
Markus Herklotz ◽  
Ahmed M. Hashem ◽  
Hanaa M. Abuzeid ◽  
Björn Schwarz ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
Sol Gel ◽  
Chelating Agent ◽  
Gel Method ◽  
Sol Gel Method

Effect of Transition Metal Ion Doping on the Photocatalytic Activities of TiO2 Synthesized by Sol-Gel Method

2012 ◽  
Vol 562-564 ◽  
pp. 260-264
Author(s):  
Min Zhong ◽  
Jing Jing Yu ◽  
Zhi Hao Wei ◽  
Ping Zhan Si
Keyword(s):  
Low Temperature ◽  
Transition Metal ◽  
Absorption Edge ◽  
Metal Ion ◽  
Sol Gel ◽  
Photocatalytic Property ◽  
Transition Metal Ions ◽  
Photocatalytic Properties ◽  
Gel Method ◽  
Sol Gel Method

Pure TiO2 , Ti 0.75 Fe0.25 O2, Ti0.75 Ni0.25 O2, Ti0.75 Co0.25 O2 nanocrystals were prepared by low temperature sol-gel method. The samples were characterized by using transmission electron microscope, X-ray diffractometer and ultraviolet-visible spectrophotometer to study the effect of transition metal ions on the photocatalytic properties of TiO2 nanocrystals. The results show that the pure TiO2 and Ti0.75 Fe0.25 O2, Ti0.75 Ni0.25 O2, Ti0.75 Co0.25 O2 nanocrystals were granular and the size of which is 3.5, 2.9, 3.6, 3.9 nm, respectively. The titania anatase phases appear in the pure TiO2 , the Ti0.75 Fe0.25 O2, Ti0.75 Ni0.25 O2, Ti0.75 Co0.25 O2. The absorption edge of Ti0.75 Fe0.25 O2occur red shift comparing with that of pure TiO2 and the absorption edge of Ti0.75 Fe0.25 O2and Ti0.75 Fe0.25 O2occur blue shift comparing with that of pure TiO2. The photocatalytic properties of pure TiO2, Ti0.75 Fe0.25 O2, Ti0.75 Fe0.25 O2, Ti0.75 Fe0.25 O2nanocrystals synthesized at low temperature by sol-gel method were investigated by degrading the methyl orange solution under ultraviolet irradiation. The degradation rate of Ti0.75 Fe0.25 O2is the highest (60%) and that of Ti0.75Co0.25O2 (10%) is the lowest among these catalysts after degradation for 120min.The result shows that the photocatalytic property ofTi0.75 Fe0.25 O2nanocrystals synthesized at low temperature is obviously better than that of pure TiO2 and Ti0.75 Fe0.25 O2, Ti0.75 Fe0.25 O2.

Structural and Optical Properties of Nickel-Doped and Undoped Zinc Oxide Thin Films Deposited by Sol-Gel Method

2014 ◽  
Vol 895 ◽  
pp. 250-253 ◽  
Author(s):  
Siti Hajar Basri ◽  
Mohd Arif Mohd Sarjidan ◽  
Wan Haliza Abd Majid
Keyword(s):  
Thin Films ◽  
Zinc Acetate ◽  
Zinc Acetate Dihydrate ◽  
Sol Gel ◽  
Chelating Agent ◽  
Zno Films ◽  
Ni Doping ◽  
Gel Method ◽  
Sol Gel Method ◽  
Glass Substrates

ZnO thin films with and without Ni-doping were successfully deposited by sol-gel method with zinc acetate dihydrate as inorganic precursor, and nickel (II) acetate tetrahydrate as dopant. The solutions were prepared by dissolving zinc acetate and nickel (II) acetate in ethanol and diethanolamine (DEA) as its chelating agent. Thin films were fabricated by using spin-coating method on glass substrates. ZnO films were obtained by pre-heating and post-heating at 300 °C for 10 minutes and 500 °C for 1 h respectively. The films were analyzed by X-ray diffraction (XRD), UV-Vis transmittance and photoluminescence (PL). All samples exhibit high transparency in visible. Ni dopant does not alter so much ZnO structure, which due to the ion substitution between Ni and Zn. However, the Ni tends to create a dopant energy interlayer in ZnO energy band gap which cause significant change in PL intensity.

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