scholarly journals Au-TiO2 Synthesized by a Microwave- and Sonochemistry-Assisted Sol-Gel Method: Characterization and Application as Photocatalyst

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1052 ◽  
Author(s):  
Rafael Hernández ◽  
José Rosendo Hernández-Reséndiz ◽  
Marisela Cruz-Ramírez ◽  
Rodrigo Velázquez-Castillo ◽  
Luis Escobar-Alarcón ◽  
...  
Keyword(s):  
Crystallite Size ◽  
Sol Gel ◽  
Synthesis Method ◽  
Physicochemical Characterization ◽  
Average Crystallite Size ◽  
Spherical Particles ◽  
One Pot ◽  
Gel Method ◽  
Sol Gel Method ◽  
Average Value

Titanium dioxide (TiO2) is a widely used and well studied photocatalyst synthesized using different methodologies, including sol-gel, which allows one to modify the material in a one-pot step. By using a microwave- and sonochemistry-assisted sol-gel method, x wt.% Au-TiO2 photocatalysts were successfully synthesized. Physicochemical characterization of the photocatalysts shows an average crystallite size of 10.5 nm and an even morphological distribution of spherical particles with the sonochemistry synthesis method. For the microwave method an average value of crystallite size of 8.3 nm was found and it presents an increase with the amount of Au load. The cyclic voltammetric response and Mott-Schottky analysis are consistent with a semiconductor material containing metallic particles and for a heterophase junction of anatase and brookite with oxygen vacancies, respectively. The photocatalytic activity was assessed by paracetamol degradation in an aqueous solution as model. The sonochemistry-synthesized photocatalysts display the most promising results as they have a better paracetamol removal and the amount of gold in the catalyst (0.7 wt.%) was found to be optimal for this process.

Effect of Praseodymium Species on the Structural and Functional Properties of Nanocrystalline BiFeO3 Powders and Thin Films

2012 ◽  
Vol 1454 ◽  
pp. 39-44
Author(s):  
Gina Montes Albino ◽  
Marco Gálvez-Saldaña ◽  
Oscar Perales-Pérez
Keyword(s):  
Thin Films ◽  
Crystallite Size ◽  
Functional Properties ◽  
Doping Level ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Gel Method ◽  
Sol Gel Method ◽  
Ferroelectric Behavior ◽  
Structural And Functional Properties

ABSTRACTThe present study addressed the effect of the incorporation of Praseodymium species in the BiFeO3(BFO) structure on the corresponding structural and functional properties of powders and films. The level of the doping species varied from 0 at% to 4 at%. BFO powders and thin films were synthesized by a sol-gel method, where glycol was aggregated to the main solvent to increase the viscosity of the precursor solutions and promote their adhesion onto platinum substrates. The development of the host BFO structure was confirmed by XRD analyses of samples annealed at 700°C for one hour (powders) or 500°C for 2 hours (thin films), in air. The average crystallite size varied from 37 nm to 41 nm and 28nm to 40nm for powders and thin films, respectively, due to the increase of the doping level. The incorporation of specific dopant species played an important role in the ferromagnetic and ferroelectric behavior in the material.

scholarly journals An Amalgam of Mg-Doped TiO2 Nanoparticles Prepared by Sol-Gel Method for Effective Antimicrobial and Photocatalytic Activity

2021 ◽  
Author(s):  
N NITHYA ◽  
S Gopi ◽  
G Bhoopathi
Keyword(s):  
Crystallite Size ◽  
Anatase Phase ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Gram Positive ◽  
Tem Analysis ◽  
Gram Negative ◽  
Gel Method ◽  
Sol Gel Method ◽  
And Shifts

Abstract In this study, undoped and Magnesium doped TiO2 nanoparticles (Mg-TiO2 NPs) were successfully synthesized via a simple sol-gel method cost-effectively. The prepared Mg- TiO2 NPs were characterized by UV-Vis, FTIR, PL, XRD, FESEM, TEM, and EDAX. UV – Visible Spectroscopy showed that an increase in the optical bandgap concerning the concentration of dopant Mg increases. The bandgap values were found to be 3.57-3.54 eV. FTIR spectra showed that the presence of the characteristic stretching and bending vibrational band of Ti – O bonding at 468 cm-1 and shifts in vibrational bands were observed for Mg-TiO2 NPs. PL spectra of Mg- TiO2 NPs at different concentrations exhibit a strong UV emission band. X-ray diffraction confirmed the formation of the tetragonal anatase phase. The average crystallite size of prepared samples was found to be 22-19 nm. The average crystallite size of Mg- TiO2 NPs decreases with increasing the concentration of dopant Mg. The FESEM and TEM analysis confirmed that the spherical morphology for both TiO2 and Mg-TiO2 NPs. SAED pattern confirms the crystalline nature of prepared samples. EDAX spectra confirm the presence of Ti, O, and Mg and confirm that Mg2+ ions are present in the TiO2 lattices. The prepared samples were investigated against gram-positive (B. subtilis and S. aureus) and gram-negative (P. eugenia and K. Pneumonia) bacteria. The prepared samples showed potent antibacterial activity against gram-negative bacteria than the gram-positive bacteria. The prepared samples show the excellent photocatalytic degradation for Methylene blue.

scholarly journals Effect of alumina incorporation on restricting grain growth of nanocrystalline tin(IV) oxide

2010 ◽  
Vol 8 (2) ◽  
pp. 331-340 ◽  
Author(s):  
Y. Al-Angari ◽  
M. Kadi ◽  
I. Ismail ◽  
Mohamed. Gabal
Keyword(s):  
Crystallite Size ◽  
Surface Area ◽  
Grain Growth ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Pure Sno2 ◽  
Gel Method ◽  
Sol Gel Method ◽  
Coated Materials ◽  
Average Grain Size

AbstractIn this project, nanocrystalline SnO2 powders were successfully prepared by (a) citrate sol-gel and (b) direct precipitation methods. Powders were characterized using thermal analysis techniques (DTA-TG-DSC), X-ray powder Diffraction (XRD), surface area (BET) and electrical conductivity measurements. XRD patterns showed the presence of the cassiterite structure. SnO2 particles, prepared through sol-gel method exhibit crystallite sizes in the range from 3.1 to 22.3 nm when the gel is heat treated at different temperatures up to 900°C. SnO2 nanocrystallites prepared by the precipitation method are comparatively larger in size. The higher specific surface area was obtained for the powder prepared using sol-gel method and the obtained average grain size (d) is relatively large compared with that of the average crystallite size. The powders show a semiconducting behavior with increasing temperature. The higher conductivity obtained for SnO2 prepared by sol-gel method can be attributed to their smaller average crystallite size. XRD of alumina doped powder exhibits finer particles than pure SnO2. TEM images showed that the particles are spherical in shape and consist of a core of SnO2 surrounded by a coating of alumina. The calculated surface area was found to decrease with temperature increases. Due to the effective role of Al2O3 additive as a grain growth inhibitor for the matrix grains, the observed surface area for the coated materials are predominantly higher than for the uncoated materials.

scholarly journals The Variation Effect of Mg-doped NPs Prepared by Sol-Gel Method on its Structural Properties and Biological Activities

2021 ◽  
Vol 2114 (1) ◽  
pp. 012004
Author(s):  
Duha S. Ahmed ◽  
Noor Q. Ali ◽  
Ali A. Taha
Keyword(s):  
Biological Activities ◽  
Sol Gel ◽  
Spherical Particles ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Nio Nps ◽  
Dopant Element ◽  
Mg Doped

Abstract In this paper, we reported the synthesis of NiO NPs and Mg doped-NiO NPs using the facile sol-gel method. Besides, the influence of the variation of Mg dopant on the structural, morphological and optical properties of the prepared Mg-NiO NPs was studied. The synthesized Mg-NiO NPs nanoparticles were characterized by X-Ray Diffraction Analysis (XRD), Energy Dispersive X-ray Spectroscopy (EDS), Fourier-Transform Infrared Spectroscopy (FTIR), Field-Emission Scanning Electron Microscopy (FE-SEM), and UV-Vis spectrophotometer. The X-ray diffraction confirmed the formation of the cubic structure of Mg doped-NiO NPs after doping with the magnesium. The increase in the crystal size was observed with the increase in the concentration of the Mg dopant element. The FESEM images reveal the formation of nickel oxide through the appearance of spherical clusters, while the hybrids appear as wrinkled surface covered with spherical particles of magnesium. The UV-Vis spectrum showed a shift towards shorter wavelengths with an increase in the concentration of the Mg dopant element due to the quantum confinement effect. The hemolysis activity study showed that NiO NPs had a low hemolysis percentage of 1.47% and increased with increasing concentration. While, increasing of the RBC hemolysis (5.9%) after NiO doped with Mg. The antibacterial activity was studied against S. aureus and P. aeruginosa bacteria, and indicated the highest growth inhibition zones of Mg-doped NiO NPs as compared with NiO NPs against of Staphylococcus aureus and Pseudomonas aeruginosa, respectively.

scholarly journals SYNTHESIS OF ZnO-Аg NANOPARTICLES BY SOL-GEL METHOD

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Savka Janković ◽  
Dragana Milisavić ◽  
Tanja Okolić ◽  
Dijana Jelić
Keyword(s):  
Zno Nanoparticles ◽  
Wide Spectrum ◽  
Sol Gel ◽  
Synthesis Method ◽  
Material Surface ◽  
Characterization Methods ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Doped Zno

Zinc oxide is a highly applicable semiconductor material. Wide applica-tion of this nanomaterial is connected to wide spectrum of energy band gap, high bond en-ergy, great thermal conductivity, but also with its non-toxicity, antibacterial activity, bio-compatibility and biodegradability characteristics. The aim of this paper is synthesis and characterization of silver doped ZnO nanoparticles (ZnO:Ag NP) using sol-gel method. Ob-tained samples of silver doped ZnO nanoparticles were characterized by following tech-niques: Fourier-transform infrared spectroscopy (FTIR), UV/VIS spectrophotometry, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spec-troscopy (EDX). Efficiency of provided synthesis method was examined by FTIR spectros-copy. XRD determined the purity and crystallinity, and wurtzite structure of synthesized material. Surface morphology and the effect of doping were examined using SEM and EDX characterization methods. Results showed better conductivity after doping ZnO nanoparti-cles with silver. SEM micrographs showed ZnO:Ag NP in the form of nanorods with a par-ticle average size of 6 nm.

Effect of Annealing Temperatures in Oxygen on the Structure and Magnetic Properties of Yttrium Iron Garnet (Y3Fe5O12) Films Prepared by a Sol-Gel Method Followed by a Spin Coating Technique

2016 ◽  
Vol 846 ◽  
pp. 626-634 ◽  
Author(s):  
Noor Baayah Ibrahim ◽  
Ftema W. Aldbea ◽  
Akmal Zaini Arsad ◽  
Noorhasniyah Md Rodee
Keyword(s):  
Magnetic Properties ◽  
Yttrium Iron Garnet ◽  
Sol Gel ◽  
Soft Magnetic Materials ◽  
Yttrium Iron ◽  
Gel Method ◽  
Sol Gel Method ◽  
Average Value ◽  
Average Grain Size ◽  
Iron Garnet

Yttrium iron garnet (Y3Fe5O12) films were prepared by a sol-gel method followed by an annealing process at 500,600,700,800, and 900°C in oxygen atmosphere for 2 hours. The microstructure characterization carried out by an X-ray diffractometer showed that the film started to crystalline into YIG phase at 700°C. The average grain size of the films measured using a field emission scanning electron microscope gave the average value of 20 to 70 nm. The magnetic properties measured by a vibrating sample magnetometer showed that all of the films were soft magnetic materials. The saturation magnetization values increased with the increment of annealing temperature. However, the coercivity values were independence with temperatures.Keywords:Thinfilms;Crystalline;Sol-gelmethod;

scholarly journals Catalytic myrtenol amination over gold, supported on alumina doped with ceria and zirconia

2018 ◽  
Vol 5 (1) ◽  
pp. 49-58 ◽  
Author(s):  
Yu.S. Demidova ◽  
I.L. Simakova ◽  
E.V. Suslov ◽  
K.P. Volcho ◽  
N.F. Salakhutdinov ◽  
...  
Keyword(s):  
Metal Oxides ◽  
Sol Gel ◽  
Gold Catalyst ◽  
Catalyst Support ◽  
Acid Sites ◽  
One Pot ◽  
Gel Method ◽  
Sol Gel Method ◽  
Alcohol Activation ◽  
The One

Abstract In the current work gold catalysts supported on both commercial oxides and oxides synthesized by the sol-gel method were used for the one-pot alcohol amination of myrtenol. In general, utilization of metal oxides synthesized by the sol-gel method as the gold catalyst support enhanced the knowledge regarding key parameters determining catalytic behavior. Synthesized alumina was characterized by stronger acid sites favoring primary amine accumulation on the catalyst surface, as compared to the commercial oxide. Utilization of mixed metal oxides synthesized by the sol-gel method resulted in the non-additive behavior of different oxides enhancing the catalytic activity. Introduction of ceria into alumina modified the support basicity resulting in more efficient alcohol activation.

Effect of Ni Substitution to Structure and Morphology of Ca0.9La0.05Bi0.05Mn1-xNixO3 by Sol-Gel Method

2020 ◽  
Vol 860 ◽  
pp. 117-121
Author(s):  
Mochammad Alfin Naufal Nur ◽  
Budhy Kurniawan
Keyword(s):  
Sol Gel ◽  
Average Crystallite Size ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Gel Method ◽  
Sol Gel Method ◽  
Electrical And Magnetic Properties ◽  
Ni Content ◽  
Average Grain Size ◽  
Ni Substitution

The polycrystalline Ca0.9La0.05Bi0.05Mn1-xNixO3 (x = 0.025, 0.05, 0.075) samples were synthesized by sol-gel method. All samples were calcined at 650°C for 8 hours and sintered at 900°C for 8 hours. The structural and morphological properties of the samples were measured by X-ray diffraction (XRD) and Scanning electron microscope (SEM). The rietveld refinement shows that all samples were having an orthorhombic structure with pnma space group despite having different Ni content. Furthermore, the average crystallite size decreases with Ni substituion. SEM result shows the average grain size decreases with increasing Ni substitution regardless of the same heat treatment. This result will affect other properties like electrical and magnetic properties.

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