scholarly journals Influence of pretreatment on the properties of α-Fe2O3 and the effect on photocatalytic degradation of methylene blue under visible light

2020 ◽  
Vol 82 (11) ◽  
pp. 2415-2424
Author(s):  
S. Mokhtari ◽  
N. Dokhan ◽  
S. Omeiri ◽  
B. Berkane ◽  
M. Trari
Keyword(s):  
Methylene Blue ◽  
Average Crystallite Size ◽  
Sample Surface ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Lattice Constants ◽  
Electrochemical Pretreatment ◽  
Crystal Properties ◽  
Rhombohedral Symmetry

Abstract The hematite (α-Fe2O3) nanostructures were synthesized by thermal oxidation of metal at 500 °C under atmospheric pressure. We studied the effect of the electrochemical pretreatment of the substrate before calcinations and its impact on the morphology, crystalline structure, lattice microstructural, and optical properties of α-Fe2O3. Uniform nanosheets were observed on the sample surface after calcination; their dimension and morphology were accentuated by the pretreatment, as confirmed by the SEM images. The characteristics of the nanostructures, analyzed by X-ray diffraction (XRD), revealed a rhombohedral symmetry with the space group R-3c and lattice constants: a = 0.5034 nm and c = 1.375 nm. The average crystallite size and strain, determined from the Williamson-Hall (W-H) plot, showed substantial variations after the substrate pretreatment. The Raman spectroscopy confirmed the changes in the crystal properties of the hematite submitted to pretreatment. The diffuse reflectance allowed to evaluate the optical gap which lies between 1.2 and 1.97 eV, induced by the electrochemical processing. The photocatalytic activity of α-Fe2O3 films was assessed by the degradation of methylene blue (MB) under LED light; 15% enhancement of the degradation for the pretreated specimens was noticed.

Synthesis and Characterization of Silver Nanoparticles Anchored on Montmorillonite via Chemical Reduction

2016 ◽  
Vol 11 ◽  
pp. 30-37 ◽  
Author(s):  
Danica Louise S. Bonga ◽  
Ma. Manna Farrel B. Pinto ◽  
Mary Fatima T. Tayad
Keyword(s):  
Ag Nanoparticles ◽  
Sodium Citrate ◽  
Chemical Reduction ◽  
Average Crystallite Size ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Clay Particles ◽  
X Ray ◽  
Mean Size

Montmorillonite clay particles were decorated with silver (Ag) nanoparticles by chemical reduction of Ag nitrate with sodium citrate. X-ray diffraction (XRD) and energy dispersive X-ray spectrometry (EDS) confirmed the presence of metallic Ag on the surface of montmorillonite. The average crystallite size of the Ag nanoparticles obtained from the broadening of the 111 Ag peak ranged at 13-16 nm. On the other hand, the apparent particle sizes obtained from the SEM images were about 79-128 nm, suggesting that the nanoparticles are polycrystalline and possibly agglomerated. The increase in the concentration of reducing agent produced smaller Ag nanoparticles with narrower size distribution. The antibacterial test showed that the Ag nanoparticles, with mean size of 79 nm, adsorbed on montmorillonite were able to inhibit the growth of Staphylococcus aureus (S. aureus) with an antimicrobial index of 0.4.

Adhesion and Electrical Properties of Copper Nitride Films

2011 ◽  
Vol 197-198 ◽  
pp. 344-347 ◽  
Author(s):  
Jian Rong Xiao ◽  
Ai Hua Jiang
Keyword(s):  
Electrical Properties ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Compact Structure ◽  
Copper Nitride ◽  
X Ray ◽  
Lattice Constants ◽  
Current Voltage ◽  
Deposition Power ◽  
Measurement Results

Copper nitride films were prepared by reactive magnetron sputtering on glass sheets at different deposition conditions. The surface morphology of the films was evaluated by a scanning electron microscope (SEM). The SEM images demonstrate that the films have a compact structure. The structure of the films was characterized by X-ray diffraction (XRD). We focused on the influence of preparation parameters on the adhesion and electrical properties of the films. The metallurgical microscope results indicate that the adhesion of the films enhances with increasing deposition power. The current-voltage (I-V) measurement results show that the resistivity of the films increases with the increasing lattice constants.

scholarly journals Determination of the crystallite size and crystal structure of magnesium powder by x-ray diffraction

2020 ◽  
Vol 20 (3) ◽  
pp. 61-65
Author(s):  
ISMAIL ISMAIL ◽  
RESI MULIANI ◽  
ZULFALINA ZULFALINA ◽  
SITI HAJAR SHEIKH MD FADZULLAH
Keyword(s):  
Crystal Structure ◽  
Crystallite Size ◽  
Rietveld Method ◽  
Average Crystallite Size ◽  
Powder Sample ◽  
X Ray Diffraction ◽  
Magnesium Powder ◽  
X Ray ◽  
Lattice Constants ◽  
Packed Structure

Magnesium powder has become an important material in the development of science and technology such as alloy and hydrogen storage. In this work, the chemical composition, crystallite size, and crystal structure of the magnesium powder sample have been studied by using x-ray fluorescent and x-ray diffraction. The x-ray diffraction data of the magnesium powder sample was analyzed by using the Rietveld method to obtain the crystal structure. Our results show that the purity of our magnesium powder sample is 93.1%. Our sample has good crystallinity with the average crystallite size of 31 nm. The crystal structure is found to be a hexagonal closed-packed structure with the lattice constants of 3.2100 Å (a and b-axis) and 5.2107 Å (c-axis). Our result revealed that the lattice constant in the c-axis of magnesium powder is influenced by impurity. This finding suggests that the impurity can affect the crystal structure of a material in general.

scholarly journals Synthesis, photocatalytic and antidiabetic properties of ZnO/PVA nanoparticles

2021 ◽  
Author(s):  
shady M. El Dafrawy ◽  
Mahmoud Tarek ◽  
Salem Samra ◽  
Shawky M. Hassan
Keyword(s):  
Methylene Blue ◽  
Biological Activity ◽  
Electron Microscope ◽  
Methyl Orange ◽  
Sol Gel ◽  
Diabetic Rats ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Scanning Electron

Abstract We prepared a series of ZnO and ZnO/PVA catalysts by sol-gel method. The wurtzite ZnO phase was confirmed by X-ray diffraction analysis (XRD). Forming spherical shaped ZnO and ZnO/PVA nanoparticles was proved by Scanning electron microscope (SEM) images. Decomposition of Methylene Blue (MB) and methyl orange (MO) by synthesized pure ZnO and ZnO/PVA nanoparticles were studied in the UV–Vis region. ZnO/5PVA was the most active in decomposition of MB, while ZnO/7PVA was the most active in decomposition of MO. By studying biological activity of pure ZnO and ZnO/PVA in diabetic rats shows that ZnO/5PVA was the most active in lowering glucose level by different percentages.

scholarly journals Chromium (III) Oxide Nanostructures Synthesized from Vernonia Amygdalina Leaves Extract

2020 ◽  
Vol 10 (1) ◽  
pp. 1856-1861
Keyword(s):  
Fourier Transform ◽  
Average Crystallite Size ◽  
Fourier Transform Infrared ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Vernonia Amygdalina ◽  
Sem Images ◽  
X Ray ◽  
Chloride Hexahydrate ◽  
Diffraction Patterns

This contribution reports first time synthesis of Cr2O3 nanostructures from chromium (III) chloride hexahydrate precursor using Vernonia amygdalina leaves extract as a reducing and stabilizing agent. Powder X-ray diffraction, Fourier-transform infrared spectroscopy, and scanning electron microscopy techniques were used to study the structural and morphological properties of the as-synthesized Cr2O3 nanostructures. Powder X-ray diffraction patterns spectral analysis showed that hexagonal Cr2O3 nanostructures with an average crystallite size of 23.4 nm were synthesized with the minor appearance of CrO2. SEM images showed that the synthesized nanomaterials are granules. Fourier-transform infrared spectra represent a sharp absorption band at 552 cm-1, which indicates Cr-O-Cr vibrational and stretching modes.

scholarly journals Synthesis of TiO2-NiFe2O4 nanocomposites using coprecipitation method as photocatalyst for methylene blue removal

2021 ◽  
Vol 882 (1) ◽  
pp. 012022
Author(s):  
A Hardian ◽  
Devikha ◽  
S Budiman ◽  
T Yuliana ◽  
H Sujono ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Textile Industry ◽  
Irradiation Time ◽  
Average Crystallite Size ◽  
Coprecipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Performance ◽  
Methylene Blue Removal ◽  
Ferrite Spinel

Abstract Methylene blue, a basic dye that is important in the coloring process in the textile industry. However, the use of the dye Methylene blue is hazardous for the skin, the eyes, and swallowed. Three composition types of TiO2-NiFe2O4 nanocomposites (75:25, 50:50, and 25:75) had been synthesized using a simple coprecipitation method. The photodegradation and adsorption performance of the nanocomposites were also evaluated. Based on X-ray diffraction analysis, both the titania anatase and nickel ferrite spinel phases appeared in each nanocomposite’s diffraction pattern. The average crystallite size of the nanocomposites was 38 nm, 33 nm, and 41 nm for compositions 75:25, 50:50, and 25:75, respectively. The optimum photodegradation activity of TiO2-NiFe2O4 nanocomposites was achieved at composition 75:25 %mol with >99% methylene blue degraded during 120 minutes of UV irradiation time. However, all nanocomposites also have adsorption capability toward methylene blue with an optimum percentage of 98%. Therefore, TiO2-NiFe2O4 nanocomposites can be used either as photocatalysts or adsorbents for methylene blue removal in an aqueous solution.

Effect of Thermal Treatment on Thermal Properties, Surface Chemistry, Crystalline Structure and Methylene Blue Removal of Polyvinyl Alcohol/TiO2 Nanocomposite Films

2020 ◽  
Vol 998 ◽  
pp. 96-101
Author(s):  
Sirinan Ratchawong ◽  
Sirirat Wacharawichanant ◽  
Siriporn Tanodekaew
Keyword(s):  
Methylene Blue ◽  
Thermal Treatment ◽  
Polyvinyl Alcohol ◽  
Average Crystallite Size ◽  
Treatment Method ◽  
Nanocomposite Films ◽  
Solution Casting ◽  
X Ray Diffraction ◽  
X Ray ◽  
Stretching Vibration

In this research, titanium dioxide (TiO2) nanoparticles were immobilized into polyvinyl alcohol (PVA) matrix without and with surfactants via solution casting film combined with thermal treatment method. The dispersion and distribution of TiO2 nanoparticles presented by scanning electron microscopy (SEM) showed the uniform distribution of TiO2 nanoparticles in PVA matrix with surfactant. Fourier-transform infrared spectroscopy (FTIR) showed increasing intensity peak at 560-800 cm-1 corresponding to Ti-O stretching vibration indicating interaction between PVA and TiO2 after thermal treatment. X-ray diffraction (XRD) result showed peak of PVA crystal structure due to the thermal treatment, and the addition of surfactant could decrease the average crystallite size of TiO2 in PVA/TiO2 nanocomposite films. Photocatalytic activity was determined from the film efficiency on removal of methylene blue (MB) under ultraviolet (UV). The results showed the greater MB removal efficiency of the PVA/TiO2 nanocomposite films with surfactant and thermal treatment than those without surfactant and thermal treatment.

Texture measurements in Al2O3 using BEKP

1994 ◽  
Vol 52 ◽  
pp. 608-609
Author(s):  
M. D. Vaudin ◽  
J. P. Cline
Keyword(s):  
Neutron Diffraction ◽  
Rapid Method ◽  
Crystallographic Orientation ◽  
Specimen Surface ◽  
X Ray Diffraction ◽  
Anisotropic Crystal ◽  
X Ray ◽  
Verification Method ◽  
Crystal Properties ◽  
Backscattered Electron

The study of preferred crystallographic orientation (texture) in ceramics is assuming greater importance as their anisotropic crystal properties are being used to advantage in an increasing number of applications. The quantification of texture by a reliable and rapid method is required. Analysis of backscattered electron Kikuchi patterns (BEKPs) can be used to provide the crystallographic orientation of as many grains as time and resources allow. The technique is relatively slow, particularly for noncubic materials, but the data are more accurate than any comparable technique when a sufficient number of grains are analyzed. Thus, BEKP is well-suited as a verification method for data obtained in faster ways, such as x-ray or neutron diffraction. We have compared texture data obtained using BEKP, x-ray diffraction and neutron diffraction. Alumina specimens displaying differing levels of axisymmetric (0001) texture normal to the specimen surface were investigated.BEKP patterns were obtained from about a hundred grains selected at random in each specimen.

scholarly journals Hydrochloric Acid Modification and Lead Removal Studies on Naturally Occurring Zeolites from Nevada, New Mexico, and Arizona

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1238
Author(s):  
Garven M. Huntley ◽  
Rudy L. Luck ◽  
Michael E. Mullins ◽  
Nick K. Newberry
Keyword(s):  
New Mexico ◽  
Surface Area ◽  
Bet Surface Area ◽  
Lead Removal ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Naturally Occurring ◽  
27Al Mas Nmr ◽  
Modified Zeolites

Four naturally occurring zeolites were examined to verify their assignments as chabazites AZLB-Ca and AZLB-Na (Bowie, Arizona) and clinoptilolites NM-Ca (Winston, New Mexico) and NV-Na (Ash Meadows, Nevada). Based on powder X-ray diffraction, NM-Ca was discovered to be mostly quartz with some clinoptilolite residues. Treatment with concentrated HCl (12.1 M) acid resulted in AZLB-Ca and AZLB-Na, the chabazite-like species, becoming amorphous, as confirmed by powder X-ray diffraction. In contrast, NM-Ca and NV-Na, which are clinoptilolite-like species, withstood boiling in concentrated HCl acid. This treatment removes calcium, magnesium, sodium, potassium, aluminum, and iron atoms or ions from the framework while leaving the silicon framework intact as confirmed via X-ray fluorescence and diffraction. SEM images on calcined and HCl treated NV-Na were obtained. BET surface area analysis confirmed an increase in surface area for the two zeolites after treatment, NM-Ca 20.0(1) to 111(4) m2/g and NV-Na 19.0(4) to 158(7) m2/g. 29Si and 27Al MAS NMR were performed on the natural and treated NV-Na zeolite, and the data for the natural NV-Na zeolite suggested a Si:Al ratio of 4.33 similar to that determined by X-Ray fluorescence of 4.55. Removal of lead ions from solution decreased from the native NM-Ca, 0.27(14), NV-Na, 1.50(17) meq/g compared to the modified zeolites, 30 min HCl treated NM-Ca 0.06(9) and NV-Na, 0.41(23) meq/g, and also decreased upon K+ ion pretreatment in the HCl modified zeolites.

scholarly journals Synthesis of Magnetic Ferrocene-Containing Polymer with Photothermal Effects for Rapid Degradation of Methylene Blue

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 558
Author(s):  
Wenhui Zhu ◽  
Caiyun Zhang ◽  
Yali Chen ◽  
Qiliang Deng
Keyword(s):  
Methylene Blue ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Degradation Rate ◽  
Model Compound ◽  
Vibrating Sample Magnetometer ◽  
Simulated Sunlight ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir

Photothermal materials are attracting more and more attention. In this research, we synthesized a ferrocene-containing polymer with magnetism and photothermal properties. The resulting polymer was characterized by Fourier-transform infrared (FT-IR), vibrating sample magnetometer (VSM), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Its photo-thermocatalytic activity was investigated by choosing methylene blue (MB) as a model compound. The degradation percent of MB under an irradiated 808 nm laser reaches 99.5% within 15 min, and the degradation rate is 0.5517 min−1, which is 145 times more than that of room temperature degradation. Under irradiation with simulated sunlight, the degradation rate is 0.0092 min−1, which is approximately 2.5 times more than that of room temperature degradation. The present study may open up a feasible route to degrade organic pollutants.

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