scholarly journals The Influence of Nd and Sm on the Structure and Properties of Sol-Gel-Derived TiO2 Powders

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3824
Author(s):  
Albena Bachvarova-Nedelcheva ◽  
Stancho Yordanov ◽  
Reni Iordanova ◽  
Irina Stambolova ◽  
Angelina Stoyanova ◽  
...  
Keyword(s):  
Sol Gel ◽  
Average Crystallite Size ◽  
Xrd Analysis ◽  
Amorphous Structure ◽  
Tio2 Anatase ◽  
E Coli ◽  
Tio2 Nanopowders ◽  
Gel Technique ◽  
Tio2 Rutile ◽  
Lower Size

TiO2 nanopowders modified by Nd and Sm were prepared using the sol-gel technique. It was found by XRD analysis that the samples containing Sm are amorphous up to 300 °C, while those with Nd preserve a mixed organic-inorganic amorphous structure at higher temperatures (400 °C). The TiO2 (rutile) was not detected up to 700 °C in the presence of both modified oxides. TiO2 (anatase) crystals found at about 400 °C in the Sm-modified sample exhibited an average crystallite size of about 25–30 nm, while doping with Nd resulted in particles of a lower size—5–10 nm. It was established by DTA that organic decomposition is accompanied by significant weight loss occurring in the temperature range 240–350 °C. Photocatalytic tests showed that the samples heated at 500 °C possess photocatalytic activity under UV irradiation toward Malachite green organic dye. Selected compositions exhibited good antimicrobial activity against E. coli K12 and B. subtilis.

Structural and Optical Characterization of Synthesized TiO2 Nanopowder Using Sol–Gel Technique

2016 ◽  
Vol 15 (01n02) ◽  
pp. 1650002 ◽  
Author(s):  
S. Lourduraj ◽  
R. Victor Williams
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Visible Spectrum ◽  
Average Crystallite Size ◽  
Xrd Analysis ◽  
Force Microscopy ◽  
Morphological Studies ◽  
Atomic Force ◽  
Gel Technique

The nanocrystalline TiO2 powder was synthesized by sol–gel method. The XRD analysis reveals that TiO2 powder was highly crystalline (anatase phase) and nanostructured with tetragonal system. The average crystallite size after calcined at 673[Formula: see text]K is found to be 7.7[Formula: see text]nm. The surface morphological studies using scanning electron microscopy (SEM) exhibit that the formation of nanosized TiO2 particles with less densification nature. Atomic force microscopy (AFM) topography exhibits the uniform distribution of spherical-shaped particles. The energy dispersive X-ray spectroscopy (EDX) confirms the presence of Titanium and Oxygen in synthesized TiO2 nanopowder. The value of optical bandgap of TiO2 nanopowder calculated from UV-Visible spectrum is 3.45[Formula: see text]eV. The presence of TiO2 particles is confirmed from the dominant fourier transform infrared (FTIR) peaks at 621[Formula: see text]cm[Formula: see text] and 412[Formula: see text]cm[Formula: see text].

scholarly journals Antibacterial Shoe Insole-Coated CuO-ZnO Nanocomposite Synthesized by the Sol-Gel Technique

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Nguyen Lam Uyen Vo ◽  
Thi Thuy Van Nguyen ◽  
Tri Nguyen ◽  
Phung Anh Nguyen ◽  
Van Minh Nguyen ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
Antibacterial Effect ◽  
Sol Gel ◽  
Average Particle Size ◽  
Point Of Zero Charge ◽  
Average Particle ◽  
E Coli ◽  
High Antibacterial Activity ◽  
Gel Technique ◽  
Shoe Insoles

In this study, CuO-ZnO composite was synthesized via the sol-gel method using oxalic acid to form the medium complex and its applications in antibacterial have been conducted with B. cereus, E. coli, S. aureus, Salmonella, and P. aeruginosa. Then, nanopowder of CuO-ZnO was coated on shoe insoles and their antibacterial effect with S. aureus was tested. The nanocomposite products were characterized by XRD, XPS, SEM, TEM, and UV-Vis. The results showed that the CuO-ZnO composite has the average particle size in a range of 20-50 nm, the point of zero charge of 7.8, and the bandgap of 1.7 eV. XPS result shows the composite structure with Cu2+ in the product. The minimum inhibitory concentration (MIC) of CuO-ZnO nanocomposite was 0.313 mg·mL-1 for S. aureus and Samonella, 0.625 mg·mL-1 for E. coli, and 5 mg·mL-1 for B. cereus and P. aeruginosa. The shoe insoles coated with 0.35 wt.% of CuO-ZnO nanocomposite also had high antibacterial activity against S. aureus, and this antibacterial nanocomposite was implanted durably on the surface of the shoe insoles.

CERIA NANOPARTICLES SYNTHESIZED BY A POLYMER PRECURSOR METHOD

2013 ◽  
Vol 22 ◽  
pp. 169-172
Author(s):  
B. SONI ◽  
S. BISWAS
Keyword(s):  
Sol Gel ◽  
Average Crystallite Size ◽  
Xrd Analysis ◽  
Poly Vinyl Alcohol ◽  
Face Centered Cubic ◽  
Ceria Nanoparticles ◽  
X Ray Diffraction ◽  
Precursor Method ◽  
Fluorite Type ◽  
Face Centered

We report a novel synthesis technique of ceria nanoparticles by a sol-gel type chemical process using poly-vinyl alcohol (PVA) as a capping as well as a reducing agent. The as-synthesized CeO 2 nanoparticles were characterized by X-ray diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM). The XRD analysis reveals the fluorite type face centered cubic structure in the ceria nanoparticles with an average crystallite size of 6 nm and 9 nm for the samples calcined at 350°C and 400°C, respectively.

scholarly journals Synthesis of Ca-Psz nanoparticles using sol-gel technique with chitosan as a dispersant for raw materials restoration and dental rehabilitation equipment

2013 ◽  
Vol 25 (3) ◽  
Author(s):  
Fadilla Rizky Prameshwari ◽  
Elin Karlina ◽  
Zulia Hasratiningsih
Keyword(s):  
Low Temperature ◽  
Raw Materials ◽  
Sol Gel ◽  
Dental Materials ◽  
Xrd Analysis ◽  
Transformation Toughening ◽  
X Ray Diffraction ◽  
Dental Rehabilitation ◽  
Gel Technique ◽  
Two Stages

Introduction: Zirconia (ZrO2) is a metal-free substance that rapidly improving as dental materials that has a good properties which are high biocompatibility, esthetics, and strength. Addition of a stabilizer like CaO will increase the mechanical properties of zirconia due to the transformation toughening. Methods: The Calcia Partially Stabilized Zirconia (Ca-PSZ) nanoparticles can be synthesized by using sol gel technique. This method makes easier to control the purity, homogeneity and physical characteristics at low temperature. This method consists of two stages, hydrolysis and condensation. The precursor were used  Zirconium Chloride (ZrCl4) with 0,1 M concentration and Calcia as stabilizer with 7% concentration. The addition of Calcia will help the tetragonal crystals forming at low temperature. Calcination temperature was used 900o C. To prevent conglomeration or agglomeration, dispersants are needed. One of the dispersants available is chitosan. Results: X-Ray Diffraction (XRD) analysis identifies that there are tetragonal and monoclinic phase with a percentage of 85% and 15% perspectively for sample without using chitosan and 100% tetragonal for sample that using chitosan. Analysis of Scanning Electron Microscope (SEM) results that particles with chitosan are more homogenous and dispersed with smaller size produced compared to particles without chitosan. Conclusion: From the results of the analysis, Ca-PSZ with sol-gel technique can produce nanoparticle and addition of  chitosan  can dispersed nanoparticles that could be used as material restoration and rehabilitation component  in dentistry.

scholarly journals Influence of some sol-gel synthesis parameters of mesoporous TiO2 on photocatalytic degradation of pollutants

2016 ◽  
Vol 22 (1) ◽  
pp. 65-73
Author(s):  
Aleksandar Golubovic ◽  
Ivana Veljkovic ◽  
Maja Scepanovic ◽  
Mirjana Grujic-Brojcin ◽  
Natasa Tomic ◽  
...  
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Tetrabutyl Titanate ◽  
Textile Dye ◽  
Reactive Orange 16 ◽  
Higher Temperature ◽  
Tio2 Nanopowders ◽  
Gel Technique ◽  
Reactive Orange ◽  
Sol Gel Synthesis

The titanium dioxide (TiO2) nanopowders were produced by sol-gel technique from tetrabutyl titanate as a precursor by varying some parameters of the sol-gel synthesis like the temperature (500 and 550 ?C) and the duration of the calcination (1.5, 2, and 2.5 h). X-ray powder diffraction (XRPD) results have shown that all synthesized nanopowders are dominantly in anatase phase, with the presence of a small amount of rutile in samples calcined at 550 ?C. According to the results obtained by Williamson-Hall method, the anatase crystallite size was increased with the duration of the calcination (from 24 to 29 nm in samples calcined at lower, and from 30 to 35 nm in samples calcined at higher temperature). The analysis of the shift and linewidth of the most intensive anatase Eg Raman mode confirmed the XRPD results. The analysis of pore structure from nitrogen sorption experimental data described all samples as mesoporous, with mean pore diameters in the range of 5-8 nm. Nanopowder properties have been related to the photocatalytic activity, tested in degradation of the textile dye (C.I. Reactive Orange 16), carbofuran and phenol.

scholarly journals Influence of Ni substitution on structural, morphological, dielectric, magnetic and optical properties of Cu–Zn ferrite by double sintering sol–gel technique

2019 ◽  
Vol 09 (02) ◽  
pp. 1950020 ◽  
Author(s):  
Mohammad Sajjad Hossain ◽  
Yeasmin Akter ◽  
Mohammad Shahjahan ◽  
Muhammad Shahriar Bashar ◽  
Most. Hosney Ara Begum ◽  
...  
Keyword(s):  
Optical Properties ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Combustion Method ◽  
Lattice Parameter ◽  
Munk Function ◽  
Zn Ferrite ◽  
Auto Combustion ◽  
Elemental Analyses ◽  
Gel Technique

Polycrystalline NiCuZn ferrite (NixCu[Formula: see text]Zn[Formula: see text]Fe2O4; [Formula: see text], 0.3, 0.4 and 0.5) were prepared through sol–gel auto combustion method applying double sintering technique. Structural, morphological, elemental analyses (EDS), Fourier-transform infrared spectroscopy (FTIR), Direct Current (DC) electrical resistivity, dielectric, magnetic and optical properties of prepared samples were analyzed. XRD profiles reveal the formation of simple cubic spinel structure without any traceable impurity. The average crystallite size lies within the range of 22–29[Formula: see text]nm. Lattice parameter decreases with increasing Ni concentration. Room temperature DC resistivity was recorded from [Formula: see text] to [Formula: see text][Formula: see text][Formula: see text][Formula: see text]cm. Both dielectric constant ([Formula: see text]) and loss factor (tan[Formula: see text]) were decreased with increase of frequency while AC conductivity increases. FTIR absorption peak occurred at three different frequency ranges at 570–577[Formula: see text]cm[Formula: see text], 1635–1662[Formula: see text]cm[Formula: see text] and 3439–3448[Formula: see text]cm[Formula: see text]. Magnetic properties were investigated by using vibrating sample magnetometer (VSM). Decreasing trends were observed for saturation magnetization ([Formula: see text]), magnetic coercivity ([Formula: see text]) and remanant magnetization ([Formula: see text]) with the increase of Ni content. Optical band gap ([Formula: see text]2.70–2.79[Formula: see text]eV) were calculated from diffuse reflectance data by using Kubelka–Munk function.

Synthesis and Characterization of PVA-Ag Doped Metals (Co, Al) Nanocomposite Thin Films Biosensors for Detection of E. coli in Water

2015 ◽  
Vol 1107 ◽  
pp. 706-711 ◽  
Author(s):  
Norshafadzila Mohammad Naim ◽  
Huda Abdullah ◽  
Noor Azwen Noor Azmy ◽  
Aidil Abdul Hamid ◽  
Mohd Ambar Yarmo ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Chemical Reduction ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Spherical Particles ◽  
Nanocomposite Thin Film ◽  
Plasmon Band ◽  
E Coli ◽  
Al Nanoparticles

Polyvinyl alcohol (PVA) doped with Ag thin films were synthesized from aqueous solution via sol gel method. The nanoparticle of silver was synthesized by chemical reduction using hydrazine hydrate. PVA-Ag thin films were deposited on the glass substrate by spin coating technique. Samples were varied with different combinations of metals such as Ag-Co and Ag-Al. The solutions and the films were characterized by using XRD, UV-Visible spectroscopy, AFM and TEM. XRD analysis indicates the formation of the single crystal Ag, Co and Al nanoparticles laid on (111) lattice planes. The crystallite sizes decrease when Co and Al are added to the PVA-Ag. UV-Vis absorption spectra confirmed the formation of Ag nanoparticles in the PVA matrix and the resonance plasmon band located at 417, 421 and 429 nm. Surface roughness of PVA-Ag nanocomposite thin film increased with the addition of Co and Al. TEM images show the non-agglomerated spherical particles in all samples. The performance of the sensor has been fabricated usingI-Vmeasurement with and without incubated the sensor electrode intoE. coli. The result shows PVA-Ag nanocomposite thin film performed the higher sensitivity.

X-ray structure determination of the rare earth oxides (Er1−uGdu)2O3applying the Rietveld method

2002 ◽  
Vol 35 (5) ◽  
pp. 577-580 ◽  
Author(s):  
Zein Heiba ◽  
Hasan Okuyucu ◽  
Y. S. Hascicek
Keyword(s):  
Rare Earth ◽  
Rietveld Method ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gel Technique ◽  
Average Size

Nanosized polycrystalline samples of (Er1−uGdu)2O3(0 ≤u≤ 1.0) were synthesized by a sol–gel technique. X-ray diffraction data were collected and the crystal structures were refined by the Rietveld method. All samples are found to have the same crystal system and formed solid solutions over the whole range ofu. The Er3+and Gd3+ions were randomly distributed over two cationic sites, 8band 24d, in the space groupIa\bar{3} (206) in all refined structures. The lattice parameter was found to vary non-linearly with the composition (u). The average microstrain and average crystallite size have been calculated from the Williamson–Hall plots for each sample. The average size ranges from 50 to 70 nm, and the microstrain from 0.4 to 1.7%.

Synthesis, Structural and Luminescent Properties of Gd2O3-SiO2:Eu3+ Nanopowder Composites

2006 ◽  
Vol 518 ◽  
pp. 455-458 ◽  
Author(s):  
M.D. Dramićanin ◽  
V. Jokanović ◽  
Z. Andrić ◽  
Bruno Viana ◽  
P. Aschehoug ◽  
...  
Keyword(s):  
Sol Gel ◽  
Fine Powder ◽  
Luminescent Properties ◽  
Xrd Analysis ◽  
Powder Form ◽  
New Techniques ◽  
Lifetime Measurements ◽  
Europium Ion ◽  
Gel Technique ◽  
Nanopowder Synthesis

In view of the improvement of luminescent intensity in classical phosphors, different new techniques of synthesis have been developed. One of them is the sol-gel technique for nanopowder synthesis. Applied to a binary system Gd2O3-SiO2 doped with trivalent europium ion, very fine powder form samples have been obtained. In that case the emission intensity of 5D0→F2 electronic transition of 4f6 configuration is greatly enhanced compared to the bulk oxide. The lifetime measurements are given too. The size of nanoparticles is of about 10 nm, determined by dynamic light scattering and XRD analysis.

scholarly journals Synthesis and comparative study on the structural and optical properties of ZnO doped with Ni and Ag nanopowders fabricated by sol gel technique

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
S. Al-Ariki ◽  
Nabil A. A. Yahya ◽  
Sua’ad A. Al-A’nsi ◽  
M. H. Hj Jumali ◽  
A. N. Jannah ◽  
...  
Keyword(s):  
Optical Properties ◽  
Sol Gel ◽  
Visible Region ◽  
Average Crystallite Size ◽  
Band Gaps ◽  
Structural And Optical Properties ◽  
Crystallite Sizes ◽  
Gel Technique ◽  
Uv Visible ◽  
Xrd Patterns

AbstractIn this work we have tried to prepare Ni and Ag doped ZnO nanopowders using the sol gel technique. The influence of Ni and Ag (1, 3 and 5 mol.%) on the crystalline structure and optical properties of ZnO was investigated. The samples were characterized by XRD, FTIR and UV–visible spectrophotometer. XRD patterns confirmed the wurtzite formation of doped and undoped ZnO nanopowders. The average crystallite sizes of the prepared samples found from XRD were 19 nm for undoped ZnO, from 17 to 22 nm for Ni-ZnO and from 19 to 26 nm for Ag-ZnO. The average crystallite size of Ag-ZnO increased with increasing Ag contents. Different optical properties of Ni-ZnO and Ag-ZnO nanopowders were observed for different Ni and Ag content. The band gaps of Ni-ZnO and Ag-ZnO nanopowders were lower than that of the undoped ZnO (3.1 eV). The band gaps of Ag-ZnO were lower than that of Ni-ZnO. The optical properties of ZnO were enhanced by Ni (mol.%) in the UV region and by Ag (3 and 5 mol.%) in the visible region.

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