scholarly journals INFLUENCE OF VANADIUM OXIDE ADDITIVE ON THERMAL TRANSFORMATIONS OF CERAMIC MASS

2021 ◽  
Vol 58 ◽  
pp. 38-45
Author(s):  
Polina Yu. Yashchenko ◽  
Keyword(s):  
Vanadium Oxide ◽  
Diffuse Reflectance Spectroscopy ◽  
Nitrogen Adsorption ◽  
Molecular Layering ◽  
Chemical Transformations ◽  
Thermal Transformations ◽  
X Ray Diffraction ◽  
Ceramic Mass ◽  
Before And After ◽  
Α Al2o3

A comparative study of thermal transformations of ceramic mass (CM) based on α-Al2O3 modified with vanadium oxide additives introduced into CM by wet mixing and by deposition on the surface of the CM particles using molecular layering nanotechnology was carried out. The structural and chemical transformations of the obtained compositions were characterized by differential thermal analysis under linear heating conditions at a rate of 10°С/min, in the temperature range from room temperature to 1000°C. Changes in the phase composition, specific surface area of the compositions, and the state of the modifying additive before and after heating were studied using x-ray diffraction, low-temperature nitrogen adsorption, and ultraviolet–visible diffuse reflectance spectroscopy

scholarly journals COMPOSITION, STRUCTURE AND TEXTURAL CHARACTERISTICS OF DOMESTIC ACID ACTIVATED BENTONITE

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Zоrаn Pеtrоvić ◽  
Pеrо Dugić ◽  
Vојislаv Аlеksić ◽  
Sаbinа Bеgić ◽  
Vlаdаn Мićić ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Low Temperature ◽  
Layered Structure ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Textural Characteristics ◽  
X Ray ◽  
Before And After ◽  
Activated Bentonite ◽  
Composition Structure

Bentonites are aluminosilicate minerals which, due to their porosity, layered structure and composition have a wide application. Structural and textural characteristics of bentonite may be improved by different modification procedures. The aim of this study was to investigate compositional, structural and textural characteristics of domestic bentonite in place Gerzovo, before and after the activation with sulfuric acid. These characteristics were investigated by analytical methods, X-ray diffraction (XRD) and the method of low-temperature nitrogen adsorption (BET). Characteristics of acid-activated bentonite were compared with the characteristics of commercial active clay. The obtained results showed that the activation of bentonite with sulfuric acid leads to a significant improvement in structural and textural characteristics. Using these results it can be assumed that this bentonite will have good adsorption characteristics and can serve as an alternative in comparison with imported commercial aluminosilicate-based adsorbents.

Preparation of Fe3O4/TiO2 magnetic mesoporous composites for photocatalytic degradation of organic pollutants

2017 ◽  
Vol 75 (7) ◽  
pp. 1523-1528 ◽  
Author(s):  
Hongfeng Zhang ◽  
Xiu He ◽  
Weiwei Zhao ◽  
Yu Peng ◽  
Donglan Sun ◽  
...  
Keyword(s):  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Magnetic Composite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mesoporous Composites ◽  
Uv Lamp ◽  
Adsorption Desorption

Fe3O4/TiO2 magnetic mesoporous composites were synthesized through a sol-gel method with tetra-n-butyl titanate as precursor and surfactant P123 as template. The as-prepared Fe3O4/TiO2 composites were characterized by X-ray diffraction, diffuse reflectance spectroscopy, nitrogen adsorption-desorption isotherm and pore size distribution. The as-synthesized products were applied as photocatalysis for the degradation of Acid Black ATT and tannery wastewater under UV lamp irradiation. Fe3O4/TiO2-8 composites containing Fe3O4 of 8 wt% were selected as model catalysts. The optimal catalyst dosage was 3 g/L in this photocalytic system. The magnetic Fe3O4/TiO2 composites possessed good photocatalytic stability and durability. This approach may provide a platform to prepare a magnetic composite to optimize the catalytic ability.

The Synthesis and Photocatalytic Performance of Samarium Doped Mesoporous Titania

2018 ◽  
Vol 876 ◽  
pp. 15-19
Author(s):  
Jian Wen Shi ◽  
Dan Dan Ma ◽  
Ya Jun Zou
Keyword(s):  
Diffuse Reflectance ◽  
Photocatalytic Performance ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Reflectance Spectroscopy ◽  
Mesoporous Titania ◽  
X Ray Diffraction ◽  
Structure Directing Agent ◽  
X Ray

The meso-porous TiO2 and Sm-doped meso-porous TiO2 were synthesized by a sol-gel method. Polyethylene glycol, with different added content, was added as a structure-directing agent. The prepared meso-porous TiO2 was characterized by nitrogen adsorption, X-ray diffraction and ultraviolet-visible diffuse reflectance spectroscopy, and the photocatalytic performance was evaluated by the decomposition of methyl orange. The results revealed that PEG plays a key role in creating porous structure during the heat-treatment. The photocatalytic performance of TiO2 is improved by adding proper content PEG, and Sm-doping can further promote the photocatalytic performance.

Combustion Synthesis of α-Al2O3 Powders

2006 ◽  
Vol 530-531 ◽  
pp. 631-636 ◽  
Author(s):  
Normanda Lino de Freitas ◽  
Elias Fagury-Neto ◽  
Hélio Lucena Lira ◽  
Lucianna Gama ◽  
Ruth Herta Goldsmith Aliaga Kiminami ◽  
...  
Keyword(s):  
Nitrogen Adsorption ◽  
Ceramic Materials ◽  
Laser Diffraction ◽  
X Ray Diffraction ◽  
Solution Composition ◽  
X Ray ◽  
Urea Content ◽  
Chemical Concepts ◽  
Α Al2o3 ◽  
New Applications

Among ceramic materials, the alumina has high importance because of its characteristics of resistance and refractory. The possibility to improve the final characteristics of this material, open possibilities for new applications. The aim of this work is to synthesize (α-Al2O3) alumina powders by combustion reaction and to evaluate the effect of the urea content in the final characteristics of the α-Al2O3 powders. Three compositions were studied : a) stoichiometric, b) with 10% of urea reduction and c) with 20% of urea reduction. The initial solution composition was based on the total valence of the reagents by using chemical concepts of the propellant. This powders were characterized by X-ray diffraction (XRD), granulometric determination by laser diffraction, nitrogen adsorption by BET, scanning electron microscopy (SEM), infrared spectroscopy (IR) and helium picnometer. The results showed that the urea reduction change the temperature of the reaction from 525 to 463oC , the characteristics of the powders, and principally the reduction of the particles size.

Reactive Adsorption of Sulfur Compounds from FCC Gasoline on NiO/γ-Al2O3

2009 ◽  
Vol 79-82 ◽  
pp. 2219-2222 ◽  
Author(s):  
Hai Yan Yin ◽  
Chun Hu Li ◽  
Lin Xue Wang ◽  
Ying Min Yu
Keyword(s):  
Nitrogen Adsorption ◽  
Sulfur Compounds ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fcc Gasoline ◽  
Reactive Adsorption ◽  
Before And After ◽  
Desulfurization Efficiency ◽  
Diffraction Patterns ◽  
Sulfur Adsorption

NiO/γ-Al2O3 adsorbent was prepared by wet impregnated method. XRD, SEM-EDS, nitrogen adsorption techniques were used to characterize the adsorbents and GC-FPD was utilized to analyze the composition of gasoline before and after reaction. X-ray diffraction patterns indicate that noncrystal NiO particles are supported on the surface of γ-Al2O3. The results show that NiO/γ-Al2O3 adsorbent could be used to remove sulfur compounds and is effective on removing benzothiophene (BT). The maximum desulfurization efficiency appears when NiO content reaches 16%, and the total sulfur adsorption capacity is 1.84mg/g, however for 16%Ni/γ-Al2O3 the value reaches 3.495mg/g.

The Corrosion and Oxidation Resistance Improvement of DZ4 Ni-Based Superalloy Irradiated by High Intensity Pulsed Ion Beams

2012 ◽  
Vol 538-541 ◽  
pp. 276-280
Author(s):  
Xian Xiu Mei ◽  
Jian Qiang Fu ◽  
Xiao Fei Liu ◽  
Jun Xu ◽  
You Nian Wang
Keyword(s):  
Oxidation Resistance ◽  
High Intensity ◽  
Irradiation Time ◽  
Ion Beam ◽  
X Ray Diffraction ◽  
Al2o3 Layer ◽  
Temperature Oxidation ◽  
Before And After ◽  
Α Al2o3 ◽  
Ion Current Density

In this paper, the DZ4 Ni-based superalloy was irradiated by high intensity pulsed C ion and H ion beam. The parameters of ion beam were: accelerating voltage 250 kV, pulse duration 70 ns, ion current density 160 A/cm2. Irradiation pulses were 2, 5, 10 and 15. The morphology of DZ4 before and after irradiation was observed by scanning electron microscope (SEM). The phase structure and stress state were analyzed by X-ray diffraction (XRD). The results show that there were some craters on the surface of the sample after irradiation, as the irradiation time increased, the crater boundary became blurred and even disappeared. The surface tensile stress produced by initial irradiation could be relieved after several irradiations pulses. The corrosion resistance of irradiated DZ4 alloy was improved greatly. The continuous and dense α-Al2O3 layer that formed on irradiated DZ4 surface at 1000°C atmosphere increased the high temperature oxidation resistance.

OLEATE-ASSISTED ROOM TEMPERATURE SYNTHESIS AND HIGH PHOTOCATALYTIC ACTIVITY OF Ag3PO4 NANOPARTICLES FOR NO DECOMPOSITION

2012 ◽  
Vol 05 (02) ◽  
pp. 1260005 ◽  
Author(s):  
LIJUN HUANG ◽  
SHU YIN ◽  
CHONGSHEN GUO ◽  
YUNFANG HUANG ◽  
MING WANG ◽  
...  
Keyword(s):  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
Nitrogen Adsorption ◽  
High Photocatalytic Activity ◽  
Area Measurement ◽  
X Ray Diffraction ◽  
Photocatalytic Ability ◽  
Silver Phosphate ◽  
Transmission Electron ◽  
Ag3po4 Nanoparticles

An oleate-assisted approach was used to synthesize nanosized spherical silver phosphate (Ag3PO4) in different solvents. The silver phosphate nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible-infrared diffuse reflectance spectroscopy (DRS), thermogravimetric analysis (TDA), and surface area measurement by nitrogen adsorption and decomposition evolution of NO x gas. The as-prepared nanoparticles showed narrow size distribution. The black colored nanoparticles could absorb most of visible light with a wavelength up to 530 nm. The DeNO x experiments revealed that the nanosized Ag3PO4 possessed a photocatalytic ability being superior to commercial P25 sample both in ultraviolet light and visible light regions.

Synthesis of γ-Bi2MoO6 Spheres and their Photocatalytic Activities for Degradation of Rhodamine B

2012 ◽  
Vol 476-478 ◽  
pp. 988-993 ◽  
Author(s):  
Shang Feng Wang ◽  
Jian Xu ◽  
Yuan Zhang ◽  
Chang Sheng Guo ◽  
Xiao Chen Li
Keyword(s):  
Visible Light ◽  
Rhodamine B ◽  
Diffuse Reflectance Spectroscopy ◽  
Photophysical Properties ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Structure Morphology ◽  
Photocatalytic Activities ◽  
Visible Light Driven ◽  
Adsorption Desorption

A highly efficient γ-Bi2MoO6 photocatalyst was synthesized by a solvethermal method with the assistance of urea. The structure, morphology and photophysical properties of the Bi2MoO6 were characterized by X-ray diffraction, scanning electron microscope, UV–vis diffuse reflectance spectroscopy and nitrogen adsorption-desorption techniques. The photocatalytic efficiencies were evaluated by the degradation of rhodamine B (RhB) under visible-light irradiation, and the γ-Bi2MoO6 structures displayed significantly higher visible-light-driven photocatalytic activity in comparison to TiO2 nanoparticles.

scholarly journals The impregnation of ZnO onto ZSM-5 derived from red mud for photocatalytic degradation of methylene blue

2022 ◽  
Vol 32 (1) ◽  
Author(s):  
Hellna Tehubijuluw ◽  
Riki Subagyo ◽  
Yuly Kusumawati ◽  
Didik Prasetyoko
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Degradation ◽  
Red Mud ◽  
Diffuse Reflectance Spectroscopy ◽  
Degradation Products ◽  
Nitrogen Adsorption ◽  
Liquid Chromatography Mass Spectrometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Desorption

AbstractPhotocatalytic degradation of Methylene Blue (MB) by zinc oxide/zeolite socony mobile-5 (ZnO/ZSM-5) composites was investigated. The ZSM-5 material was synthesized from red mud by a two-step hydrothermal method to which ZnO loadings at different mass ratios were subsequently performed. Characterizations using X-ray diffraction (XRD), Fourier transform infrared spectroscopy, and scanning electron microscopy were carried out to identify the formation of ZSM-5 and ZnO/ZSM-5. ZSM-5 and ZnO/ZSM-5 have cubic microcrystallite morphologies. ZnO loading in the ZnO/ZSM-5 composites was successfully performed and confirmed by the appearance of wurtzite peaks in the XRD spectra that matched the Joint Committee on Powder Diffraction Standards data. The presence of ZnO in ZSM-5 leading resulted in a decrease in the surface area and pore size as confirming by nitrogen adsorption-desorption isotherm experiments. The band gap of the samples was measured using UV-Vis diffuse reflectance spectroscopy. The optimum photocatalytic degradation of MB was observed at a ZnO loading of 34% w/w dubbed 34-ZnO/ZSM-5. The influence of the initial concentration of MB was also investigated at 80, 90, and 100 mg L− 1 using 34-ZnO/ZSM-5 and ZSM-5. Liquid chromatography–mass spectrometry characterization was performed to analyze the degradation products.

Microwave-Assisted Synthesis of a Series of Ag/ZnO Nanocomposites and Evaluation of Their Photocatalytic Activities under Multi-Mode Photodegradation

2015 ◽  
Vol 68 (5) ◽  
pp. 774 ◽  
Author(s):  
Li Li ◽  
Xiandan Huang ◽  
Yu Gao ◽  
Wenzhi Zhang ◽  
Xiuli Zhang ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Diffuse Reflectance Spectroscopy ◽  
Nitrogen Adsorption ◽  
Microwave Assisted Synthesis ◽  
X Ray Diffraction ◽  
Surface Areas ◽  
Photocatalytic Activities ◽  
Surface Physicochemical Properties ◽  
Adsorption Desorption ◽  
Multi Mode

A series of Ag/ZnO nanocomposites were prepared under microwave irradiation of different powers (100, 200, and 300 W). The crystal structure, morphology, and surface physicochemical properties of the as-synthesized samples were characterized by X-ray diffraction, UV–visible diffuse reflectance spectroscopy, scanning electron microscopy, and nitrogen adsorption–desorption analyses. Compared with the Ag/ZnO prepared by conventional sedimentation process, the crystal structures of Ag and ZnO did not exhibit any transformation after microwave irradiation; however, slight increases or decreases were observed in their absorption spectra and the specific surface areas. Moreover, the morphologies of all Ag/ZnO samples were changed dramatically by microwave irradiation, showing morphologies such as octagonal nano-pyramidal and multi-angled nano-pyramidal. The multi-mode photocatalytic degradation studies showed that the photocatalytic activities of the Ag/ZnO nanocomposites prepared under microwave irradiation of different powers were enhanced to different extents and were much higher than that of P25, ZnO, and Ag/ZnO prepared in the absence of microwave irradiation.

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