scholarly journals Nanostructured titanium dioxide average size from alternative analysis of Scherrer's Equation

2018 ◽  
Vol 23 (1) ◽  
Author(s):  
Francisco Marcone Lima ◽  
Felipe Mota Martins ◽  
Paulo Herbert França Maia Júnior ◽  
Ana Fabíola Leite Almeida ◽  
Francisco Nivaldo Aguiar Freire

ABSTRACT The materials sizing in nano-scale is a challenge to be overcome, because the size determined by various methods differ. In order to shed light about the nanomaterials sizing, a modified Scherrer's equation was applied to estimate more accurately the nanostructured titanium dioxide crystal size. The manufactured titanium dioxide-nanostructured powder with nominal average size about 21nm was used as the reference standard to determine the accurate of modified equation. From X-ray diffraction data, an average crystal size about 20.63 nm was achieved for unheated sample. To establish a relation between the result obtained with modified Scherrer's equation and the nominal average crystal size, a statistical treatment and a comparative assessment were performed. The average absolute divergence does not exceed 0.70 nm. The value of crystal size determined from X-ray data was in good agreement with that informed by the supplier. Additionally, the behavior of sample was studied as a function of temperature.

2005 ◽  
Vol 19 (15n17) ◽  
pp. 2734-2739 ◽  
Author(s):  
JUN GENG ◽  
JIAN-RONG ZHANG ◽  
JIAN-MIN HONG ◽  
JUN-JIE ZHU

Lead tungstate ( PbWO 4) an important inorganic scintillator, was synthesized via a mild sonochemical route from an aqueous solution of lead acetate and sodium tungstate in the presence of complexing agents under ambient air. X-ray diffraction (XRD), transmission electron microscope (TEM) and photoluminescence (PL) were used to characterize the products. The as-prepared PbWO 4 nanocrystals crystallize in a tetragonal structure and have an average crystal size of ca. 10 nm.


2018 ◽  
Vol 7 (4.37) ◽  
pp. 22 ◽  
Author(s):  
Assist. Prof. Ali S. Ali ◽  
Alaa J. Mohammed ◽  
Haider R. Saud

The powder of TiO2/α-Al2O3 nanocomposite for Sonocatalysis decolorisation was successfully achieved in the Hydrothermal autoclave reaction for 6 hours and completely crystallized into Anatase phase at temperature of 220oC which more lower than normal required calcination temperature 500oC. The TiO2/α-Al2O3 nanoparticles examined using FT-IR, SEM, TGA, X-ray diffraction studies( XRD), The results indicate the formation of nanocomposite with tetragonal Anatase phase and average crystal size of 21.4nm for TiO2/α-Al2O3 while the average crystal size of 8.1nm for Al2O3, which are calculated according to Scherrer’s equation. This powder was mixed with methylene blue to study the effect of nanocomposite on it, the prepared nanocomposite show highly decolorisation percentage of methylene blue solution. 


2010 ◽  
Vol 177 ◽  
pp. 41-44
Author(s):  
Jing Li ◽  
Bao Wu Pan

α-Al2O3 nanocrystalline powder was prepared via precipitation method, and the effect of reactant concentration on the nanocrystal structure was investigated by X-Ray diffraction. Firstly, α-Al2O3 phase was analyzed by continuous scanning, first strong peaks of allα-Al2O3 phase were step scanned then to determinate the most perfect crystal structure, and the crystal lattice constants and average crystal size of the best crystal structure were calculated finally. The result showed that X-ray diffraction was an elementary and necessary means for the crystal structure study, it also offered a new way to select preparation process, and the application of it would develop along with the develop of new materials. The most perfect α-Al2O3 nanocrystal structure was obtained with the reactant solution of 0.65mol/L, and its lattice constants were a-4.746xc-12.917Å and the average crystal size was 59nm.


2006 ◽  
Vol 05 (02n03) ◽  
pp. 239-243 ◽  
Author(s):  
HUAMING YANG ◽  
RONGRONG SHI ◽  
KE ZHANG ◽  
YUEHUA HU ◽  
HUIHUI ZHANG ◽  
...  

Synthesis of uniform nanocrystalline anatase TiO 2 by sol–gel method was investigated using different thermal analysis (DTA), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. Thermal treatment of the precursor at 350°C for 2 h in air results in the formation of nanocrystalline anatase TiO 2 with the average crystal size of 21.5 nm. Quantitative analysis through energy dispersive X-ray spectroscopy (EDS) indicated that the atomic ratio of Ti:O ≈ 1:1 is close to the stoichiometric ratio of TiO 2, leading to the evident fact that the prepared nanoparticles are indeed the TiO 2 material.


Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 937
Author(s):  
Yingying Hu ◽  
Md Rasadujjaman ◽  
Yanrong Wang ◽  
Jing Zhang ◽  
Jiang Yan ◽  
...  

By reactive DC magnetron sputtering from a pure Ta target onto silicon substrates, Ta(N) films were prepared with different N2 flow rates of 0, 12, 17, 25, 38, and 58 sccm. The effects of N2 flow rate on the electrical properties, crystal structure, elemental composition, and optical properties of Ta(N) were studied. These properties were characterized by the four-probe method, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE). Results show that the deposition rate decreases with an increase of N2 flows. Furthermore, as resistivity increases, the crystal size decreases, the crystal structure transitions from β-Ta to TaN(111), and finally becomes the N-rich phase Ta3N5(130, 040). Studying the optical properties, it is found that there are differences in the refractive index (n) and extinction coefficient (k) of Ta(N) with different thicknesses and different N2 flow rates, depending on the crystal size and crystal phase structure.


2005 ◽  
Vol 38 (5) ◽  
pp. 749-756 ◽  
Author(s):  
Ulrich Gesenhues

The polygonization of 200 nm rutile crystals during dry ball-milling at 10gwas monitored in detail by means of transmission electron microscopy (TEM) and X-ray diffraction (XRD). The TEM results showed how to modify the Williamson–Hall method for a successful evaluation of crystal size and microstrain from XRD profiles. Macrostrain development was determined from the minute shift of the most intense reflection. In addition, changes in pycnometrical density were monitored. Accordingly, the primary crystal is disintegrated during milling into a mosaic of 12–35 nm pieces where the grain boundaries induce up to 1.2% microstrain in a lower layer of 6 nm thickness. Macrostrain in the interior of the crystals rises to 0.03%. The pycnometrical density, reflecting the packing density of atoms in the grain boundary, decreases steadily by 1.1%. The results bear relevance to our understanding of plastic flow and the mechanism of phase transitions of metal oxides during high-energy milling.


2021 ◽  
Vol 21 (11) ◽  
pp. 5592-5602
Author(s):  
Samira Almasi ◽  
Ali Mohammad Rashidi

The effect of the yttria-stabilized zirconia (YSZ) nanoparticle loading in an electro-less bath was considered as one of the vital synthesis variables for control Ni content and microstructure of prepared nanocomposite particles, which are two crucial factors to achieving high-performance SOFC anode. Nanocomposite particles were prepared using a simple electroless method without any expensive pretreatment of sensitizing by Sn2+ ions as well as activating by Pd2+ ions that are usually used to apply nickel coating on the surface of a non-conductive substrate. The process was performed by adding YSZ nanoparticles into NaOH solution, separating them from the solution by the centrifugal method, then providing several water-based nanofluids with different concentrations of activated YSZ nanoparticles, mixing them with NiCI2 solution, followed by adding the hydrazine and then NaOH solution. X-ray diffraction and scanning electron microscopy coupled with energy dispersive X-ray analysis were used to analyze the prepared nanocomposite particles. It is observed that after adding YSZ nanoparticles into the NaOH solution, the pH of the solution varied gradually from a starting pH of 10.2 to 9. Also, by increasing the YSZ nanoparticles loading in the electroless bath from 76 mg/l to 126 mg/l, the grain size of Ni deposits, the Ni content and the average size of the prepared nanocomposite particles decreased. The electrochemical mechanism previously proposed for the nickel ion reduction was modified, and a novel analytical model was proposed for variation of the efficiency of Ni deposition with YSZ nanoparticles loading.


2018 ◽  
Vol 788 ◽  
pp. 102-107
Author(s):  
Pavels Rodionovs ◽  
Jānis Grabis ◽  
Aija Krūmiņa

In order to improve TiO2 photocatalytic activity ZnFe2O4/TiO2 nanocomposites with different ZnFe2O4 mass loading were produced. Obtained ZnFe2O4 nanoparticles were coupled with TiO2 via microwave-assisted hydrothermal method in order to improve photon absorption in a range of visible light. Prepared nanostructures were characterized with scanning electron microscopy and X-ray diffraction. Photocatalytic activity of prepared samples was investigated by degradation of methylene blue under different light sources – LED, Hg and Osram Vitalux lamps. ZnFe2O4 consists of spherical nanoparticles with average size of 15 nm. TiO2 spherical nanoparticles size is in a range of 30÷45 nm. The results show that doping TiO2 with ZnFe2O4 nanoparticles increases photocatalytic activity. Photocatalytic activity increases as mass loading of ZnFe2O4 decreases.


Author(s):  
А.Я. Пак ◽  
Г.Я. Мамонтов

AbstractWe describe a method of obtaining ultrafine boron carbide (B_13C_2) powder using the effect of a dc electric arc on a mixture of initial reactants containing carbon and boron. A peculiarity of the proposed method is that it can be implemented using arc discharge operating in open air without any vacuum equipment and protective inert gas atmosphere. X-ray diffraction data showed that the synthesized product in the general case contained three crystalline phases: boron carbide (B_13C_2), graphite (C), and boron oxide (B_2O_3). Electron-microscopic examination showed that the average size of boron carbide particles ranged from ~50 nm to ~2 μm.


2015 ◽  
Vol 2 (1) ◽  
pp. 15-17
Author(s):  
Indira J

Hydroxyapatite (HAP) nanoparticles with uniform morphologies and controllable size have been synthesized by template directed method. The environment and eco-friendly polysaccharide soluble starch is used as a template to regulate size and shape of the nanoparticles synthesized. Structural and morphological properties of as-synthesized hydroxyapatite nanoparticles have been examined through the techniques like Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD) and Scanning Electron Microscopy(SEM), respectively. The results indicate that the obtained particles are uniform discrete spherical nanoparticles. The average size of the hydroxyapatite nanoparticles were ranged from 45 to 60 nm.


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