SOL-GEL SYNTHESIS AND CHARACTERIZATION OF COPPER STABILIZED ZIRCONIA NANOPARTICLES

2011 ◽  
Vol 25 (21) ◽  
pp. 2823-2839 ◽  
Author(s):  
Y. VAHIDSHAD ◽  
H. ABDIZADEH ◽  
H. R. BAHARVANDI ◽  
M. AKBARI BASERI
Keyword(s):  
Particle Size ◽  
Hydrogen Production ◽  
Calcination Temperature ◽  
Aging Temperature ◽  
Sol Gel ◽  
Chelating Agent ◽  
Molar Ratio ◽  
Gel Method ◽  
Sol Gel Method ◽  
Sol Gel Synthesis

A sol-gel method is investigated to synthesize CuO – ZrO 2 nanoparticles as catalyst for hydrogen production from methanol. Finer precursor nanoparticles give rise to larger specific areas in catalyst which result in a high hydrogen production. The effects of some critical process parameters on the sol-gel synthesis of CuO – ZrO 2 nanoparticles are studied. These parameters are affected on synthesis of CuO – ZrO 2 when it is prepared with sol-gel method. Particle size and distribution are considered as the results. The parameters including the effect of calcination temperature, aging temperature, nature and concentration of catalyst (acidic or basic conditions), H 2 O /precursor molar ratio, and chelating agent that have been identified as most important, are focused. It is found that the calcination temperature strongly influenced the morphology and interaction between the active species and support, and hence the structure and catalytic performance. Nature and concentration of catalyst ( pH value), chelating agent, ( H 2 O /precursor) molar ratio and also aging temperature have influence on the nanoparticles. Thus, by controlling these factors, it is possible to vary the morphology and properties of the sol-gel-derived inorganic network over wide ranges. Morphology, particle size and distribution, phase evaluation, structure, and chemical analysis of the products are investigated by SEM, TEM, DTA/TG, XRD and EDX respectively.

Synthesis of Ag/ZnO Nanocomposite with Excellent Photocatalytic Performance via a Facile Sol-Gel Method

2014 ◽  
Vol 875-877 ◽  
pp. 251-256 ◽  
Author(s):  
Lin Sun ◽  
Rong Shao ◽  
Lan Qin Tang ◽  
Zhi Dong Chen
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Calcination Temperature ◽  
Photocatalytic Performance ◽  
Sol Gel ◽  
Bet Surface Area ◽  
Molar Ratio ◽  
Gel Method ◽  
Sol Gel Method ◽  
Ft Ir

Ag/ZnO nanocomposite photocatalysts with high photocatalytic performance were successfully synthesized via a facile sol-gel method. The prepared Ag/ZnO products were characterized by XRD, SEM, EDS, FT-IR, BET surface area, TG and DSC. Photodegradation experiments of the samples were carried out by choosing Methylene Blue (MB) as a model target under UV irradiation with homemade photocatalytic apparatus. Among these products, when the molar ratio of Ag to ZnO was fixed at 0.07 and the calcination temperature was around 450 °C, the obtained samples exhibited the highest photocatalytic activity.

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.

Sol–gel synthesis of fine-particle superconducting oxide, YBa2Cu3O7−x

1988 ◽  
Vol 3 (5) ◽  
pp. 810-812 ◽  
Author(s):  
P. Ravindranathan ◽  
S. Komarneni ◽  
A. Bhalla ◽  
R. Roy ◽  
L. E. Cross
Keyword(s):  
Particle Size ◽  
Fine Particle ◽  
Single Phase ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method ◽  
Sol Gel Synthesis

A sol-gel method of preparing fine-particle superconducting oxide YBa2Cu3O7−x was developed. Single-phase superconducting oxide YBa2Cu3O7−x formed at temperatures as low as 750°. The particle size obtained by this method was found to be ≤0.2μm. Pellets sintered from these sol-gel powders exhibited very sharp resistivity drops at Tc = 90 °C with a Δc of ∼3°K.

Influence of Calcination Temperature on Lattice Parameters and Particle Size ofR2CuO4Compounds (R= Gd, Nd) Prepared by a Sol–Gel Method

1996 ◽  
Vol 122 (1) ◽  
pp. 25-30 ◽  
Author(s):  
J. Mahı́a ◽  
A. Vieiro ◽  
J. Mira ◽  
J. Rivas ◽  
M.A. López-Quintela ◽  
...  
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
Sol Gel ◽  
Lattice Parameters ◽  
Gel Method ◽  
Sol Gel Method

Annealing Effects on the Physical and Magnetic Properties of Tb1.5Y1.5Fe5O12 Films Nanoparticles Prepared by Sol-Gel Method

2013 ◽  
Vol 756 ◽  
pp. 91-98 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Annealing Temperature ◽  
Quartz Substrate ◽  
Sol Gel ◽  
Lattice Parameter ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Iron Garnet

Terbium –substituted yttrium iron garnet (Tb1.5Y1.5Fe5O12) films nanoparticles were successfully prepared by a sol-gel method. The films were deposited on the quartz substrate using spin coating technique. To study effect of annealing temperature, the annealing process was executed at 700, 800 and 900 °C in air for 2 hours. The X-ray diffraction (XRD) proved that the pure phase of garnet structure was detected for the film annealed at 900 °C. The lattice parameter increased with the increment of annealing temperature and the highest value of 12.35 Å was obtained at 900 °C. Field Emission Scanning Electron Microscope (FE-SEM) results showed that the particle size increased from 43nm to 56nm as annealing temperature increased from 700 to 900°C. The film’s thickness also affected by increasing of annealing temperature and become thin at 900 °C due to densification process occurred at high annealing temperature. The elemental compositions of the Tb1.5Y1.5Fe5O12 film were detected using an Energy Dispersive X-raySpectroscopy (EDX). Magnetic properties at room temperature were measured using a Vibrating Sample Magnetometer (VSM).The saturation magnetization Ms increased with the annealingtemperature and showed a high value of 104emu/cm3, but the coercivity Hc of the film was decreased due to the increment of the particle size. Normal 0 21 false false false MS X-NONE X-NONE MicrosoftInternetExplorer4 Terbium –substituted yttrium iron garnet (Tb1.5Y1.5Fe5O12) films nanoparticles were successfully prepared by a sol-gel method. The films were deposited on the quartz substrate using spin coating technique. To study effect of annealing temperature, the annealing process was executed at 700, 800 and 900°C in air for 2 hours. The X-ray diffraction (XRD) proved that the pure phase of garnet structure was detected for the film annealed at 900 °C. The lattice parameter increased with the increment of annealing temperature and the highest value of 12.35 Å was obtained at 900 °C. Field Emission Scanning Electron Microscope (FE-SEM) results showed that the particle size increased from 43nm to 56nm as annealing temperature increased from 700 to 900 °C. The film’s thickness also affected by increasing of annealing temperature and become thin at 900 °C due to densification process occurred at high annealing temperature. The elemental compositions of the Tb1.5Y1.5Fe5O12 film were detected using an Energy Dispersive X-ray Spectroscopy (EDX). Magnetic properties at room temperature were measured using a Vibrating Sample Magnetometer (VSM).The saturation magnetization Ms increased with the annealing temperature and showed a high value of 104emu/cm3, but the coercivity Hc of the film was decreased due to the increment of the particle size. st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

scholarly journals Bismuth Oxide Prepared by Sol-Gel Method: Variation of Physicochemical Characteristics and Photocatalytic Activity Due to Difference in Calcination Temperature

2020 ◽  
Vol 21 (1) ◽  
pp. 108
Author(s):  
Yayuk Astuti ◽  
Brigita Maria Listyani ◽  
Linda Suyati ◽  
Adi Darmawan
Keyword(s):  
Photocatalytic Activity ◽  
Band Gap ◽  
Calcination Temperature ◽  
Bismuth Oxide ◽  
Sol Gel ◽  
Physicochemical Characteristics ◽  
Band Gap Energy ◽  
Gel Method ◽  
Sol Gel Method ◽  
Body Center Cubic

Research on synthesis of bismuth oxide (Bi2O3) using sol-gel method with varying calcination temperatures at 500, 600, and 700 °C has been done. This study aims to determine the effect of calcination temperature on the characteristics of the obtained products which encompasses crystal structure, surface morphology, band-gap energy, and photocatalytic activity for the decolorization of methyl orange dyes through its kinetic study. Bismuth oxide prepared by sol-gel method was undertaken by dissolving Bi(NO3)3·5H2O and citric acid in HNO3. The mixture was stirred then heated at 100 °C. The gel formed was dried in the oven and then calcined at 500, 600, and 700 °C for 5 h. The obtained products were a pale yellow powder, indicating the formation of bismuth oxide. This is confirmed by the existence of Bi–O and Bi–O–Bi functional groups through FTIR analysis. All three products possess the same mixed crystal structures of α-Bi2O3 (monoclinic) and γ-Bi2O3 (body center cubic), but their morphologies and band gap values are different. The higher the calcination temperature, the larger the particle size and the smaller the band gap value. The accumulative differences in characteristics appoint SG700 to have the highest photocatalytic activity compared to SG600 and SG500 as indicated by its percent degradation value and decolorization rate constant.

scholarly journals Synthesis of Spherical Silica by Sol-Gel Method and Its Application as Catalyst Support

2011 ◽  
Vol 10 (2) ◽  
pp. 25
Author(s):  
Anirut Leksomboon ◽  
Bunjerd Jongsomjit
Keyword(s):  
Particle Size ◽  
Ethylene Glycol ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Sol Gel ◽  
Weight Ratio ◽  
Gel Method ◽  
Sol Gel Method ◽  
Spherical Silica

In this present study, the spherical silica support was synthesized from tetraethyloxysilane (TEOS), water, sodium hydroxide, ethylene glycol and n-dodecyltrimethyl ammonium bromide (C12TMABr). The particle size was controlled by variation of the ethylene glycol co-solvent weight ratio of a sol-gel method preparation in the range of 0.10 to 0.50. In addition, the particle size apparently increases with high weight ratio of co-solvent, but the particle size distribution was broader. The standard deviation of particle diameter is large when the co-solvent weight ratio is more than 0.35 and less than 0.15. However, the specific surface area was similar for all weight ratios ranging from 1000 to 1300 m2/g. The synthesized silica was spherical and has high specific surface area. The cobalt was impregnated onto the obtained silica to produce the cobalt catalyst used for CO2 hydrogenation.</

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