scholarly journals Synthesis of Fe2O3 nanoparticles and their applications in methylene blue treatment

2021 ◽  
Vol 9 (4) ◽  
Author(s):  
Mai Nguyen Vu Ngoc ◽  
Nhiem Dao Ngoc ◽  
Chuc Pham Ngoc ◽  
Dung Doan Trung ◽  
Chi Nguyen Thi Ha ◽  
...  
Keyword(s):  
Single Phase ◽  
Solution Temperature ◽  
Gel Formation ◽  
X Ray Diffraction ◽  
Photocatalytic Ability ◽  
Factors Affecting ◽  
X Ray ◽  
Structure Morphology ◽  
Average Grain Size ◽  
Process Factors

In this study, nano Fe2O3 particles were synthesized by the combustion of gel from polyvinyl acohol (PVA) and tartaric acid (TA) for the degradation of methyl blue (MB) from the aqueous solution by the photocatalytic process. Factors affecting on Fe2O3 formation such as the pH of solution, temperature of gel formation, mole ratio of TA/PVA, temperature of calcination were investigated. The structure, morphology of Fe2O3 particles were characterized by analysis methods such as Differential Thermal Analysis, X- Ray Diffraction and Field Emission Scanning Electron Microscopy. The results showed that single-phase Fe2O3 was smaller than 60 nm of average grain size. When using Fe2O3 to investigate the photocatalytic capacity under the visible light irradiation, the results indicated that Fe2O3 catalysts showed a rather high photocatalytic ability to decompose MB. The intermediates coming from the photocatalytic degradation were identified.

scholarly journals Synthesis of Fe2O3 nanoparticles and their applications in methylene blue treatment

2020 ◽  
Vol 9 (4) ◽  
Author(s):  
Mai Nguyen Vu Ngoc ◽  
Nhiem Dao Ngoc ◽  
Chuc Pham Ngoc ◽  
Dung Doan Trung ◽  
Chi Nguyen Thi Ha ◽  
...  
Keyword(s):  
Single Phase ◽  
Solution Temperature ◽  
Gel Formation ◽  
X Ray Diffraction ◽  
Photocatalytic Ability ◽  
Factors Affecting ◽  
X Ray ◽  
Structure Morphology ◽  
Average Grain Size ◽  
Process Factors

In this study, nano Fe2O3 particles were synthesized by the combustion of gel from polyvinyl acohol (PVA) and tartaric acid (TA) for the degradation of methyl blue (MB) from the aqueous solution by the photocatalytic process. Factors affecting on Fe2O3 formation such as the pH of solution, temperature of gel formation, mole ratio of TA/PVA, temperature of calcination were investigated. The structure, morphology of Fe2O3 particles were characterized by analysis methods such as Differential Thermal Analysis, X- Ray Diffraction and Field Emission Scanning Electron Microscopy. The results showed that single-phase Fe2O3 was smaller than 60 nm of average grain size. When using Fe2O3 to investigate the photocatalytic capacity under the visible light irradiation, the results indicated that Fe2O3 catalysts showed a rather high photocatalytic ability to decompose MB. The intermediates coming from the photocatalytic degradation were identified.

Preparation of Heterojunction Semiconductor SnS2/SnO2 with Enhanced Photocatalytic Properties

2013 ◽  
Vol 316-317 ◽  
pp. 1059-1062 ◽  
Author(s):  
Ping Chen ◽  
Ming Sheng Qin ◽  
Fu Qiang Huang
Keyword(s):  
Photocatalytic Activity ◽  
Single Phase ◽  
Near Infrared ◽  
Photocatalytic Performance ◽  
Chemical Compositions ◽  
X Ray Diffraction ◽  
Simple Method ◽  
X Ray ◽  
Structure Morphology ◽  
Nir Absorption

The Formation of Heterojunction Structure between Two Semiconductors Was Considered as an Effective Method to Enhance the Photocatalytic Activity. here, we Reported a Simple Method to Prepare SnS2/SnO2Heterojunction Photocatalysts by Annealing SnS2in Air. the Structure, Morphology, Chemical Compositions and Optical Properties of the Obtained Materials Were Characterized by the X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Energy-dispersive X-ray Spectroscopy (EDX) and Ultraviolet-visible-near Infrared (UV-Vis-NIR) Absorption Spectra. the Photocatalytic Investigations Showed the Composites Have Higher Photocatalytic Activity than the Single-phase SnS2. the SnS2Powder which Annealed at 400 °C for 60 Min Showed the Highest Photocatalytic Performance.

Influence of Annealing Time on Microstructure of Ni-W Alloys

2013 ◽  
Vol 747-748 ◽  
pp. 613-618
Author(s):  
Qiao Zhang ◽  
Shu Hua Liang ◽  
Chen Zhang ◽  
Jun Tao Zou
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Grain Size ◽  
Grain Boundaries ◽  
Annealing Time ◽  
Single Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Average Grain Size ◽  
Scanning Electron

The as-cast Ni-W alloys with 15wt%W, 25wt%W and 30wt%W were annealed in hydrogen at 1100. The effect of the annealing time on the microstructure of Ni-W alloys was studied, and the phase constituents and microstructure of annealed Ni-W alloys were characterized by the X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that no any phase changed for Ni-15%W, Ni-25%W and Ni-30%W alloys annealed for 60 min, 90 min and 150 min, which were still consisted of single-phase Ni (W) solid solution. However, microstructure had a significant change after annealing. With increase of annealing time, the microstructure of Ni-15%W alloy became more uniform after annealing for 90 min, and the average grain size was 95μm, whereas the grain size of Ni-15%W alloy increased significantly after annealing for 150 min. For Ni-25%W and Ni-30%W, there was no obvious change on the grain size with increase of annealing time, and the amount of oxides at grain boundaries gradually reduced. After annealing for 150 min, the impurities at grain boundaries almost disappeared. Subsequently, the annealing at 1100 for 150 min was beneficial for the desired microstructure of Ni-25%W and Ni-30%W alloys.

PREPARATION AND CHARACTERIZATION OF CIS POWDERS BY A FACILE REFLUXING REACTION ROUTE

2013 ◽  
Vol 12 (05) ◽  
pp. 1350031
Author(s):  
J. C. ZHOU ◽  
Y. Y. WANG ◽  
X. L. GONG ◽  
S. W. LI
Keyword(s):  
Single Phase ◽  
Stoichiometric Composition ◽  
Chalcopyrite Structure ◽  
Crystallographic Structure ◽  
X Ray Diffraction ◽  
Reaction Route ◽  
X Ray ◽  
Structure Morphology ◽  
Short Time

CuInSe 2 (CIS)-based powders were successfully prepared by a facile refluxing reaction route using metal halides and Se / S powder as raw starting materials. The phase and crystallographic structure, morphology, chemical composition of the products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS). It is found that single phase CIS powders with chalcopyrite structure can be prepared in a relatively short time using triethylenetetramine as the solvent; the most suitable reaction temperature and time are 200°C, 1–2 h, respectively. CuIn ( S x Se 1-x)2 powders were also prepared by refluxing reaction route using the mixed solvent of triethylenetetramine–glycol (1:1, v/v). The characterizations showed that the CuIn ( S x Se 1-x)2 has single chalcopyrite phase, and the stoichiometric composition closely follows the primary mixed ratio. The morphology of CuIn ( S x Se 1-x)2 is close to spheres, and the particle sizes become distinctly smaller with the incorporation of S . A possible formation mechanism of CuInSe 2 was put forward and briefly discussed.

scholarly journals Structural And Electrical Properties Of The Selected Rare-Earth Oxychlorides

2015 ◽  
Vol 60 (3) ◽  
pp. 1595-1602 ◽  
Author(s):  
M. Dziubaniuk ◽  
J. Wyrwa ◽  
M. Bućko ◽  
M. Rękas
Keyword(s):  
Rare Earth ◽  
Electrical Properties ◽  
Single Phase ◽  
Electrochemical Impedance ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Average Grain Size ◽  
Structural And Electrical Properties ◽  
Sintering Conditions

Abstract The preparation and sintering conditions of the selected rare-earth oxychlorides REOCl (Re=La, Nd, Sm, Gd) were determined. The purity of materials phase compositions was confirmed by X-ray diffraction method. Further analysis of the data enabled lattice parameters and average grain size determination. The electrical properties of the single phase REOCl materials were investigated by Electrochemical Impedance Spectroscopy in wide temperature range in atmospheric air. The spectra were analyzed by the equivalent circuit fitting. Basing on the values of equivalent circuits parameters the specific conductivities were calculated and presented in the Arrhenius coordinates. Energies of activation were calculated. The determined structural and electrical properties of four different rare-earth oxychlorides were directly compared.

scholarly journals Struktur dan Sifat Dielektrik Senyawa Aurivillius CaBi3LaTi4O15 yang Disintesis dengan Teknik Hidrotermal

2020 ◽  
Vol 11 (1) ◽  
pp. 9-15
Author(s):  
Zulhadjri Zulhadjri ◽  
Firmanul Qadri Amir ◽  
Marsal Mahmud ◽  
Upita Septiani ◽  
Syukri Arief
Keyword(s):  
Crystal Structure ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Aurivillius Phase ◽  
Orthorhombic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Hydrothermal Technique ◽  
X Ray ◽  
Structure Morphology ◽  
Ferroelectric Transition Temperature

Synthesis of four-layer Aurivillius CaBi3LaTi4O15 has been successfully carried out by hydrothermal technique using NaOH 4 M as mineralizer. The reaction was carried out at 220 °C for 72 h. Crystal structure, morphology, and dielectric properties were analyzed in this study. X-ray diffraction confirmed that the single-phase product was successfully obtained. The refinement result shows the product has orthorhombic crystal structure with space group A21am. The morphology analyzed using SEM shows plate-like grains are observed, which is characteristic of Aurivillius phase. Dielectric curves show peaks at 585 °C which indicate ferroelectric transition temperature.

scholarly journals Effect of Nd Substitution on the Microstructural and Dielectric Properties of Polycrystalline Ca(Ti0.5Fe0.5)O3

2013 ◽  
Vol 61 (1) ◽  
pp. 125-129 ◽  
Author(s):  
MR Shah ◽  
MR Amin ◽  
AKM Akther Hossain
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Solid State Reaction Technique ◽  
X Ray ◽  
Average Grain Size ◽  
Iron Titanate ◽  
Higher Temperature ◽  
Calcium Iron

Neodymium substituted calcium iron titanate having the general formula Ca1-xNdx(Ti0.5Fe0.5)O3 were prepared by the standard solid state reaction technique at relatively higher temperature (1473 K). X-ray diffraction (XRD) and optical microscopy are used to carry out the structural analysis and surface morphology, respectively. The XRD analysis confirms that all compositions are single phase orthorhombic in structure. The lattice parameters and the average grain size are found to decrease but the density to increase with the increase in Nd content. The dielectric constant (?/), dielectric loss (tan?) and ac conductivity (?ac) are studied at room temperature as a function of frequency and compositions. The room temperature ?/ is found to decrease with the increase in frequency and Nd content. On the other hand, the tan? and ?ac are observed to increase with the increase in frequency and decrease with the increase in Nd content. Dhaka Univ. J. Sci. 61(1): 125-129, 2013 (January) DOI: http://dx.doi.org/10.3329/dujs.v61i1.15113

Raman And Fluorescence Spectra Observed in Laser Microprobe Measurements of Several Compositions in the Ln-Ba-Cu-O System

1990 ◽  
Vol 48 (2) ◽  
pp. 278-279
Author(s):  
Edgar S. Etz ◽  
Thomas D. Schroeder ◽  
Winnie Wong-Ng
Keyword(s):  
Fluorescence Spectra ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Ceramic Powders ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Raman Microprobe ◽  
Methods Of Synthesis ◽  
Compositional Homogeneity ◽  
Processing Techniques

We are investigating by Raman microprobe measurements the superconducting and related phases in the LnBa2Cu3O7-x (for x=0 to 1) system where yttrium has been replaced by several of the lanthanide (Ln = Nd,Sm,Eu,Ho,Er) elements. The aim is to relate the observed optical spectra (Raman and fluorescence) to the compositional and structural properties of these solids as part of comprehensive materials characterization. The results are correlated with the methods of synthesis, the processing techniques of these materials, and their superconducting properties. Of relevance is the substitutional chemistry of these isostructural systems, the differences in the spectra, and their microanalytical usefulness for the detection of impurity phases, and the assessment of compositional homogeneity. The Raman spectra of most of these compounds are well understood from accounts in the literature.The materials examined here are mostly ceramic powders prepared by conventional solid state reaction techniques. The bulk samples are of nominally single-phase composition as determined by x-ray diffraction.

Observation of pseudo 10-fold symmetry in the ordered iron-zinc delta phase

1992 ◽  
Vol 50 (1) ◽  
pp. 36-37
Author(s):  
L. A. Giannuzzi ◽  
A. S. Ramani ◽  
P. R. Howell ◽  
H. W. Pickering ◽  
W. R. Bitler
Keyword(s):  
Single Phase ◽  
X Ray Diffraction ◽  
Rich Region ◽  
Average Cell ◽  
X Ray ◽  
Delta Phase ◽  
Cell Dimensions ◽  
Δ Phase ◽  
Morphological Differences ◽  
Concentration Discontinuity

The δ phase is a Zn-rich intermetallic, having a composition range of ∼ 86.5 - 92.0 atomic percent Zn, and is stable up to 665°C. The stoichiometry of the δ phase has been reported as FeZn7 and FeZn10 The deviation in stoichiometry can be attributed to variations in alloy composition used by each investigator. The structure of the δ phase, as determined by powder x-ray diffraction, is hexagonal (P63mc or P63/mmc) with cell dimensions a = 1.28 nm, c = 5.76 nm, and 555±8 atoms per unit cell. Later work suggested that the layer produced by hot-dip galvanizing should be considered as two distinct phases which are characterized by their morphological differences, namely: the iron-rich region with a compact appearance (δk) and the zinc-rich region with a columnar or palisade microstructure (δp). The sub-division of the δ phase was also based on differences in diffusion behavior, and a concentration discontinuity across the δp/δk boundary. However, work utilizing Weisenberg photographs on δ single crystals reported that the variation in lattice parameters with composition was small and hence, structurally, the δk phase and the δp phase were the same and should be thought of as a single phase, δ. Bastin et al. determined the average cell dimensions to be a = 1.28 nm and c = 5.71 nm, and suggested that perhaps some kind of ordering process, which would not be observed by x-ray diffraction, may be responsible for the morphological differences within the δ phase.

Effect of Temperature on Fe3O4 Magnetic Nanoparticles Prepared by Coprecipitation Method

2014 ◽  
Vol 900 ◽  
pp. 172-176 ◽  
Author(s):  
Ji Mei Niu ◽  
Zhi Gang Zheng
Keyword(s):  
Magnetic Nanoparticles ◽  
Coprecipitation Method ◽  
Effect Of Temperature ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnetic Carriers ◽  
Average Grain Size ◽  
Or Gene ◽  
Block Temperature

The Fe3O4 magnetic nanoparticles obtained by the aqueous coprecipitation method are characterized systematically using scanning electron microscope, X-ray diffraction and vibrating sample magnetometer. These magnetic nanoparticles are spheric, dispersive, and have average grain size of 50 nm. The size and magnetic properties of Fe3O4 nanoparticles can be tuned by the reaction temperature. All samples exhibit high saturation magnetization (Ms=53.4 emu·g-1) and superparamagnetic behavior with a block temperature (TB) of 215K. These properties make such Fe3O4 magnetic nanoparticles worthy candidates for the magnetic carriers of targeted-drug or gene therapy in future.

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