Effect of Calcination Temperature on Phase Transformation and Microstructure of Al2O3/GdAlO3 Compound Powder Prepared by Co-Precipitation Method

2012 ◽  
Vol 512-515 ◽  
pp. 535-538 ◽  
Author(s):  
Shuai Sun ◽  
Qiang Xu
Keyword(s):  
Calcination Temperature ◽  
Raw Materials ◽  
Metastable Phase ◽  
Precipitation Method ◽  
Calcination Process ◽  
Compound Powder ◽  
Average Grain Size ◽  
Different Temperatures ◽  
Diffraction Peaks ◽  
Co Precipitation

A Coprecipitation Method Was Applied to Synthesize Al2O3/GdAlO3 Compound Powder, Using Ammonia as the Precipitator. Gadolinium Oxide and Aluminium Nitrate Were Used as the Raw Materials with the Eutectic Ratio( 77 mol% Al 3+ – 23 mol% Gd 3+ ). the Precursor Was Calcined at Different Temperatures from 1200 to 1600 °C. the Phase Identifications at Different Temperatures Were Characterized by X-ray Diffractometry (XRD). the Growth Morphology of Particles Were Investigated Using Field Emission Electro Microscopy (FE-SEM). the Results Reveal that GdAlO3 Crystallized Earlier than α-Al2O3. the Diffraction Peaks of α-Al2O3 Phase Were Observed after Calcination at 1300°C for 1 H. Metastable Phase Gd3Al5O12 Underwent Complete Decomposition at 1600°C for 1 H. Gadolinium Aluminate and α-Al2O3 Showed Different Growth Mechanism during the Calcination Process. the Average Grain Size of the Calcined Powder Increased from ~40 to ~900 Nm as the Calcination Temperature Increased from 1200 to 1600 °C.

Flexible synthesis of high-performance electrode materials of N-doped carbon coating MnO nanowires for supercapacitors

2021 ◽  
Author(s):  
Ting Zhou ◽  
Wenjun Zhang ◽  
Hao Fu ◽  
Jingyuan Fang ◽  
Chunnian Chen ◽  
...  
Keyword(s):  
Calcination Temperature ◽  
High Performance ◽  
Electrode Materials ◽  
Precipitation Method ◽  
High Power Density ◽  
N2 Atmosphere ◽  
Different Temperatures ◽  
The Difference ◽  
Co Precipitation ◽  
Nanowire Structure

Abstract The MnO/C composites were obtained by co-precipitation method, which used Mn3O4 nanomaterials as precursors and dopamine solution after ultrasonic mixing and calcination under N2 atmosphere at different temperatures. By studying the difference of MnO/C nanomaterials formed at different temperatures, it was found that with the increase of calcination temperature, the materials appear obvious agglomeration. The optimal calcination temperature is 400 °C, and the resulting MnO/C is a uniformly dispersed slender nanowire structure. The specific capacitance of MnO/C nanowires can reach 356 F g-1 at 1 A g-1. In the meantime, the initial capacitance of MnO/C nanowires remains 106% after 5000 cycles. Moreover, the asymmetric supercapacitor (ASC) was installed, which displays a tremendous energy density of 30.944 Wh kg-1 along with a high power density of 10 kW kg-1. The composite material reveals a promising prospect in the application of supercapacitors.

Effect of Zn:Sn Ratio and Calcination Temperature on Phase Transformation of Zn-Sn-O Compound

2016 ◽  
Vol 675-676 ◽  
pp. 539-543
Author(s):  
Puritut Nakhanivej ◽  
Thanit Tangcharoen ◽  
Wanichaya Mekprasart ◽  
Wisanu Pecharapa
Keyword(s):  
Phase Transformation ◽  
Calcination Temperature ◽  
Spinel Phase ◽  
Mixed Phase ◽  
Precipitation Method ◽  
Study Phase ◽  
Different Temperatures ◽  
Xrd Patterns ◽  
Co Precipitation ◽  
Surface Morphologies

Zn-Sn-O powders were synthesized by simple co-precipitation method combined with calcination process using zinc chloride (ZnCl2) and tin (IV) chloride pentrahydrate (SnCl4–5H2O) as starting precursors of Zn and Sn in aqueous solution. The effect of precursors ratio on phase structure of Zn-Sn-O compound was investigated by varying ratio of Zn:Sn in the co-precipitation system. For the effect of calcination temperature, the as-precipitated product obtained at Zn:Sn ratio of 1:1 was calcined at different temperatures (400-900 °C) to study phase transformation. Structural properties of as-precipitated and after-calcined powders were characterized by X-ray diffraction (XRD) while surface morphologies of final products were observed by scanning electron microscope (SEM), and thermogravimetric analysis (TGA) was used to study their thermal properties. The results indicate that the XRD pattern of Zn-Sn-O powders obtained at ratio of Zn greater than Sn can be assigned to mixed phase of ZnO and Zn2SnO4. On the other hand the XRD patterns of products obtained at ratio of Sn greater than Zn confirm a mixture of SnO2 and Zn2SnO4. For the effect of calcination temperature, the rarely spinel phase of Zn2SnO4 begin occur with mixed phase of ZnO and SnO2 at the calcination temperature of 600 °C and pure spinel structure can be obtained at the temperature above 900 °C.

Effect of the Synthesis Method on the Properties of Ultrafine YAG Powder

2018 ◽  
Vol 281 ◽  
pp. 40-45
Author(s):  
Jie Guang Song ◽  
Lin Chen ◽  
Cai Liang Pang ◽  
Jia Zhang ◽  
Xian Zhong Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
Hydrothermal Reaction ◽  
Synthesis Method ◽  
Particle Morphology ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Synthesis Process ◽  
Powder Materials ◽  
Co Precipitation

YAG materials has a number of unique properties, the application is very extensive. In this paper, the superfine YAG powder materials were prepared by co-precipitation method and hydrothermal precipitation method. The influence of synthesis process on the morphology of the powder was investigated. The results showed that the precursor powder prepared via the co-precipitation method is mainly from amorphous to crystalline transition with the increasing calcination temperature, the precursor agglomeration is more serious, In the process of increasing the calcination temperature, the dispersibility of the roasted powder is greatly improved, which is favorable for the growth of the crystal grains, so that the particle size of the powder is gradually increased, the YAG precursor prepared by the co-precipitation method is transformed into YAG crystals, the phase transition occurs mainly between 900 and 1100°C. When the molar ratio of salt to alkali is Y3+: OH-=1: 8 via the hydrothermal reaction, the YAG particles with homogeneous morphology can be obtained. When the molar ratio of salt and alkali is increased continuously, the morphology of YAG particles is not obviously changed. The co-precipitation method is easy to control the particle size, the hydrothermal method is easy to control the particle morphology.

Preparation of Nanoscale CuO Powders

2010 ◽  
Vol 113-116 ◽  
pp. 1770-1773 ◽  
Author(s):  
Xi Hua Zhao ◽  
Min Xu
Keyword(s):  
Raw Materials ◽  
Precipitation Method ◽  
Optimum Conditions ◽  
Muffle Furnace ◽  
Factors Affecting ◽  
Direct Precipitation ◽  
Average Grain Size ◽  
Scherrer Formula ◽  
Average Size ◽  
Direct Precipitation Method

Cu(OH)2 precursor was synthesized by direct precipitation method and CuSO4 and NaOH were used as raw materials. Then, Cu(OH)2 precursor was calcined in muffle furnace at 400°C for 2h in order that CuO particle was obtained. Through the analysis of the factors affecting the CuO, the paper determined the optimum conditions for the synthesis of nano-CuO with the direct-precipitation method. Then the paper analyzed phase composition and crystal structure of samples using XRD and calculated the average grain size of samples by Scherrer formula, and observed and analyzed by TEM to characterize the morphology and particle size of samples. The optimum precipitation conditions are as follows: when the precipitation agent is 3.2:1, reaction time 40min and precipitant concentration 0.6mol.L-1. The average size of CuO particle prepared under the conditions is 18nm and the yield is 96%.

Structural and Optical Properties of Pure NiO Nanoparticles and NiO-Mn2O3, NiO-CdO, NiO-Pb2O3, NiO-ZnO Nanocomposites

2021 ◽  
Vol 14 (5) ◽  
pp. 409-417
Keyword(s):  
Nickel Oxide ◽  
Green Emission ◽  
Hexagonal Structure ◽  
Precipitation Method ◽  
Nio Nanoparticles ◽  
Structural And Optical Properties ◽  
Suitable Material ◽  
Structure Morphology ◽  
Average Grain Size ◽  
Co Precipitation

Abstract: Pure nickel oxide (NiO) nanoparticles and NiO-Mn2O3, NiO-CdO, NiO-Pb2O3, NiO –ZnO nanocomposites were synthesized by co-precipitation method. The PXRD studies revealed that NiO, Mn2O3 and CdO possessed cubic structure, Pb2O3 possessed monoclinic structure, ZnO possessed hexagonal structure and confirmed the presence of polycrystallinity nature of NiO and Mn2O3, CdO, Pb2O3, ZnO in the nanocomposites. The average grain size of NiO nanoparticles was found to be 30.10 nm using Debye Scherer’s formula. The FESEM images of NiO nanoparticles and their nanocomposites revealed spherical shaped structure and NiO-Pb2O3 revealed needle shaped rod-like structure. EDAX analysis confirmed the composition of NiO nanoparticles and their nanocomposites. Raman spectra exhibited characteristic peaks of pure NiO and that of NiO- Mn2O3, NiO-CdO, NiO- Pb2O3, NiO-ZnO in the synthesized nanocomposites. In the PL spectra, blue and green emission was observed in the samples. UV-vis spectra revealed the absorption peaks of NiO nanoparticles and their nanocomposites. Thus, the synthesized NiO- Mn2O3, NiO-CdO, NiO - Pb2O3 and NiO-ZnO nanocomposites can be a suitable material for electrocatalysis applications. Keywords: Nickel oxide nanocomposites, Structure, Morphology, Absorption, Luminescence.

Preparation and Electrochemical Performance of Mn3O4/GR Composites Electrode Material in Supercapacitors

2019 ◽  
Vol 807 ◽  
pp. 50-56
Author(s):  
Yun Long Zhou ◽  
Zhi Biao Hu ◽  
Li Mei Wu ◽  
Jiao Hao Wu
Keyword(s):  
Room Temperature ◽  
Raw Materials ◽  
Precipitation Method ◽  
Electrochemical Performances ◽  
Manganese Sulfate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
A Current ◽  
Discharge Test

Using hydrated manganese sulfate and general type graphene (GR) as raw materials, Mn3O4/GR composite has been successfully prepared by the liquid phase chemical co-precipitation method at room temperature. X-ray diffraction (XRD) was used to investigate the phase structure of Mn3O4powder and Mn3O4/GR composite; The electrochemical performances of the samples were elucidated by cyclic voltammetry and galvanostatic charge-discharge test in 0.5 mol/L Na2SO4electrolyte. The results show that the Mn3O4/GR composite possesses graphene phase and good reversibility; the composite also displays a specific capacitance of 318.8 F/g at a current density of 1 A/g.

scholarly journals Synthesis of Co3O4 Nano Aggregates by Co-precipitation Method and its Catalytic and Fuel Additive Applications

2019 ◽  
Vol 17 (1) ◽  
pp. 865-873 ◽  
Author(s):  
Muhammad Ramzan Saeed Ashraf Janjua
Keyword(s):  
Electron Microscopy ◽  
Precipitation Method ◽  
Fuel Additive ◽  
X Ray Diffraction ◽  
Efficient Catalyst ◽  
Calcination Process ◽  
Electron Microscopies ◽  
Transmission Electron ◽  
Co Precipitation ◽  
Individual Particles

AbstractThe nano aggregates of cobalt oxide (Co3O4) are synthesized successfully by adopting simple a co precipitation approach. The product obtained was further subjected to the calcination process that not only changed it morphology but also reduces the size of individual particles of aggregates. The prepared nano aggregates are subjected to different characterization techniques such as electron microscopies (scanning electron microscopy and transmission electron microscopy) and X-ray diffraction and results obtained by these instruments are analyzed by different software. The characterization results show that, although the arrangement of particles is compact, several intrinsic spaces and small holes/ pores can also be seen in any aggregate of the product. The as synthesized product is further tested for catalytic properties in thermal decomposition of ammonium perchlorate and proved to be an efficient catalyst.

Synthesis of Uniform Barium Ferrite Powders by Co-Precipitation Method

2017 ◽  
Vol 898 ◽  
pp. 1649-1654 ◽  
Author(s):  
Min Chen ◽  
Run Hua Fan ◽  
Zi Dong Zhang ◽  
Yan Sheng Yin ◽  
Li Hua Dong
Keyword(s):  
Calcination Temperature ◽  
Barium Ferrite ◽  
Water Bath ◽  
Precipitation Method ◽  
Ammonium Bromide ◽  
Barium Ferrites ◽  
Hexagonal Barium Ferrite ◽  
Crystallite Sizes ◽  
Co Precipitation ◽  
Hexadecyltrimethyl Ammonium Bromide

The uniform hexagonal barium ferrite powders were synthesized by co-precipitation method using metal chloride. The effects of the amount of hexadecyltrimethyl ammonium bromide (CTAB), the water bath and calcination temperature on the phase formation, microstructure and density of barium ferrites were systematically investigated. The results showed that the formation of uniform hexagonal barium ferrite powders was significantly influenced by the amount of CTAB and the water bath could lead to the larger grain size and density. The SEM demonstrated that the BaFe12O19 powders had plate-like shape with crystallite sizes varing from 150 to 200 nm. When the amount of CTAB was 0.2g/100ml and the calcination temperature was 850 °C, the barium ferrite powders were uniform which indicated that the amount of surfactant and calcination temperature were very optimum.

The Influence of Calcination Temperature on Quantitative Phase of Hematite from Iron Stone Tanah Laut

2015 ◽  
Vol 1112 ◽  
pp. 489-492
Author(s):  
Ali Mufid ◽  
M. Zainuri
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
Thermo Gravimetric Analysis ◽  
Precipitation Method ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Particle Size Analyzer ◽  
Co Precipitation

This research aims to form particles of hematite (α-Fe2O3) with a basis of mineral iron ore Fe3O4 from Tanah Laut. Magnetite Fe3O4 was synthesized using co-precipitation method. Further characterization using X-ray fluorescence (XRF) to obtain the percentage of the elements, obtained an iron content of 98.51%. Then characterized using thermo-gravimetric analysis and differential scanning calorimetry (TGA-DSC) to determine the calcination temperature, that at a temperature of 445 °C mass decreased by 0.369% due to increase in temperature. Further Characterization of X-ray diffraction (XRD) to determine the phases formed at the calcination temperature variation of 400 °C, 445 °C, 500 °C and 600 °C with a holding time of 5 hours to form a single phase α-Fe2O3 hematite. Testing with a particle size analyzer (PSA) to determine the particle size distribution, where test results indicate that the α-Fe2O3 phase of each having a particle size of 269.7 nm, 332.2 nm, 357.9 nm, 412.2 nm. The best quantity is shown at a temperature of 500 °C to form the hematite phase. This result is used as the calcination procedure to obtain a source of Fe ions in the manufacture of Lithium Ferro Phosphate.

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