Synthesis of Nanostructured Iron Oxide(III) Powders by Rapid Expansion of Supercritical Fluid Solutions

1998 ◽  
Vol 520 ◽  
Author(s):  
A.A. Burukhin ◽  
B.R. Churagulov ◽  
N.N. Oleynikov ◽  
Yu.V. Kolen'Ko
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Iron Oxide ◽  
Solid State ◽  
Supercritical Fluid ◽  
Solid State Reaction ◽  
Zinc Ferrite ◽  
Rapid Expansion ◽  
Molar Ratio ◽  
Supercritical Aqueous Solution

ABSTRACTNanostructured a-Fe2O3 powders were generated by rapid expansion of supercritical fluid solutions (RESS, T=773 K, P=100 MPa) and by rapid thermal decomposition of precursors in solution ( RTDS, T=623 K, P=100 MPa) on lab RESS-setup from 0,040 M and 0,10 M aqueous solutions of Fe(NO3)3. The size of subcrystallites is about 22-29 nm. Comparison of reactivity of α-Fe2O3 powders in a model solid state reaction between a-Fe2O3 powders (generated by RESS from 0,040 M solution) and Li2CO3 (mole ratio 1:1) with literature data on a-Fe2O3 powders produced by other methods shows that its reactivity is markedly higher. A basic essence possibility of zinc ferrite ZnFe2O4 formation immediately at the stage of the rapid expansion (T=773K; P=100 MPa) of a supercritical aqueous solution of zinc and iron nitrates (molar ratio Zn:Fe=1:2; C=0. 1 M) was shown.

Enhanced adsorption removal of methyl orange from aqueous solution by nanostructured proton-containing δ-MnO2

2015 ◽  
Vol 3 (10) ◽  
pp. 5674-5682 ◽  
Author(s):  
Yan Liu ◽  
Chao Luo ◽  
Jian Sun ◽  
Haizhen Li ◽  
Zebin Sun ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Methyl Orange ◽  
Solid State ◽  
Solid State Reaction ◽  
Proton Exchange ◽  
Precipitation Method ◽  
Homogeneous Precipitation ◽  
Adsorption Removal ◽  
Homogeneous Precipitation Method ◽  
Enhanced Adsorption

Two nanostructured proton-containing δ-MnO2 (H-δ-MnO2) materials were synthesized through proton exchange for K-containing δ-MnO2 (K-δ-MnO2) nanosheets and nanoparticles prepared by the hydrothermal homogeneous precipitation method and solid-state reaction.

scholarly journals Effect of Bi2O3 content on the microstructure and electrical properties of SrBi2Nb2O9 piezoelectric ceramics

RSC Advances ◽  
2018 ◽  
Vol 8 (28) ◽  
pp. 15613-15620 ◽  
Author(s):  
Xiaochun He ◽  
Ruiqing Chu ◽  
Zhijun Xu ◽  
Zhongran Yao ◽  
Jigong Hao
Keyword(s):  
Solid State ◽  
Electrical Properties ◽  
Solid State Reaction ◽  
Solid State Reaction Method ◽  
Lead Free ◽  
Molar Ratio ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
Lead Free Ceramics ◽  
Bi2o3 Content

Lead-free ceramics, SrBi2Nb2O9–xBi2O3 (SBN–xBi), with different Bi contents of which the molar ratio, n(Sr) : n(Bi) : n(Nb), is 1 : 2(1 + x/2) : 2 (x = −0.05, 0.0, 0.05, 0.10), were prepared by conventional solid-state reaction method.

Photocatalytic Degradation of Methyl Orange on Iron Niobate Prepared by Solid-State Reaction

2010 ◽  
Vol 113-116 ◽  
pp. 2021-2024 ◽  
Author(s):  
Wen Jie Zhang ◽  
Xin Sun ◽  
Bai Han Chen
Keyword(s):  
Methyl Orange ◽  
Solid State ◽  
Photocatalytic Degradation ◽  
Solid State Reaction ◽  
Irradiation Time ◽  
Molar Ratio ◽  
Preparation Conditions ◽  
New Type ◽  
Iron Niobate ◽  
Degradation Of Methyl Orange

Iron niobate photocatalyst as a new type of photocatalyst was prepared by solid-state reaction of Fe3O4 and Nb2O5 and its activity was evaluated using photocatalytic degradation of methyl orange. Preparation conditions such as calcination temperature and time, and irradiation time were investigated according to photocatalytic efficiencies. FeNb2O6 was produced during calcination below 700 oC and FeNbO4 was produced above 800 oC. Iron niobate with optimum activity could be prepared after calcination at 700 oC for 8 h when Fe:Nb molar ratio was 0.8:1. Methyl orange degradation rate was 72.7% after 180 min of irradiation at photocatalyst concentration of 4 g/l.

Solid state synthesis, characterization, optical properties and cooperative catalytic performance of bismuth vanadate nanocatalyst for Biginelli reactions

RSC Advances ◽  
2015 ◽  
Vol 5 (31) ◽  
pp. 24313-24318 ◽  
Author(s):  
Shahin Khademinia ◽  
Mahdi Behzad ◽  
Hamideh Samari Jahromi
Keyword(s):  
Optical Properties ◽  
Solid State ◽  
Solid State Reaction ◽  
Raw Materials ◽  
Catalytic Performance ◽  
Bismuth Vanadate ◽  
Solid State Synthesis ◽  
Molar Ratio ◽  
Biginelli Reactions

Bi2V2O7 nano powders were synthesized via a solid state reaction at 500 °C for 8 h using Bi(NO3)3 and VO(acac)2 at stoichiometric 1 : 1 Bi : V molar ratio as raw materials.

Optimizing the silanization of thermally-decomposed iron oxide nanoparticles for efficient aqueous phase transfer and MRI applications

RSC Advances ◽  
2016 ◽  
Vol 6 (96) ◽  
pp. 93784-93793 ◽  
Author(s):  
Xin-Yang Wang ◽  
Damien Mertz ◽  
Cristina Blanco-Andujar ◽  
Anindita Bora ◽  
Mathilde Ménard ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Aqueous Phase ◽  
Phase Transfer ◽  
Oxide Nanoparticles

A facile silanization method allows to efficiently stabilise in aqueous solution iron oxide NPs synthesized by thermal decomposition for MRI applications.

scholarly journals Synthesis of Cubic Phase-Co Microspheres by Mechanical Solid-State Reaction-Thermal Decomposition and Research on Its Growth Kinetics

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Ying Deng ◽  
Yanhua Zhang ◽  
Lingling Peng ◽  
Xiaolong Jing ◽  
Hui Chen
Keyword(s):  
Thermal Decomposition ◽  
Solid State ◽  
Grain Growth ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Energy Content ◽  
Industrial Applications ◽  
Cubic Phase ◽  
Oxalate Precursor ◽  
Cobalt Oxalate

Cubic phase cobalt (Co), which can be used as a key component for composite materials given its excellent ductility and internal structure, is not easy to obtain at room temperature. In this study, oxalic acid and cobalt nitrate are used as raw materials to synthesize the cobalt oxalate precursor, which has a stable structure with a five-membered chelate ring. Cobalt oxalate microspheres, having a high internal energy content, were prepared by using mechanical solid-state reaction in the presence of a surfactant, which can produce spherical micelles. The thermal decomposition of the precursor was carried out by maintaining it in a nitrogen atmosphere at 450°C for 3 h. At the end of the procedure, 100 nm cubic phase-Co microspheres, stable at room temperature, were obtained. Isothermal and nonisothermal kinetic mechanisms of cobalt grain growth were investigated. The cubic-Co grain growth activation energy, Q, was calculated in this study to be 71.47 kJ/mol. The required reaction temperature was low, making the production process simple and suitable for industrial applications.

X-ray powder diffraction studies of a new compound: Th13Te24O74

2002 ◽  
Vol 17 (1) ◽  
pp. 32-36 ◽  
Author(s):  
S. N. Tripathi ◽  
S. N. Achary ◽  
P. N. Namboodiri
Keyword(s):  
Thermal Decomposition ◽  
Solid State ◽  
Powder Diffraction ◽  
Solid State Reaction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Diffraction Patterns ◽  
Direct Solid ◽  
Measured Density

The compound Th13Te24O74 was prepared by three independent methods, namely, thermal decomposition of ThTe2O6 in oxygen and argon and direct solid-state reaction of ThO2 and TeO2. The X-ray powder diffraction patterns of the three products, by and large, are similar, except for some differences in intensities and extra diffraction lines. The thermal decomposition of ThTe2O6 was carried out in the streams of oxygen and argon by thermogravimetry at a heating rate of 5 K/min in the temperature range of 725–840 °C. The solid-state reaction of ThO2 and TeO2 (13:24) was carried out in a sealed ampoule at 700 °C. The measured density of this compound is 8.23 g/cm3. An orthorhombic lattice with unit cell parameters, a=11.310±0.005 Å, b=14.064±0.006 Å, c=9.056±0.004 Å, and volume of 1440.419±1.088 (Å)3 was determined for this compound.

Preparing LiFePO4 Using Recovered Materials from Waste Li-Ion Battery

2013 ◽  
Vol 726-731 ◽  
pp. 2940-2944 ◽  
Author(s):  
Feng Pei ◽  
Yue Wu ◽  
Wen Hua Zhang ◽  
Xu Tian ◽  
Ji Yu
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Raw Material ◽  
Molar Ratio ◽  
Li Ion Battery ◽  
Optimal Conditions ◽  
Initial Discharge Capacity ◽  
Capacity Retention ◽  
Initial Discharge ◽  
Li Ion

LiFePO4 was prepared using recovered materials from waste Li-ion battery. The recovered materials after treatment was mixed with Li2CO3, Fe (NO3) 3·9H2O and NH4H2PO4 to adjust the Li/Fe/P molar ratio equal to 1.05/1/1. The raw material was mixed with super-p and calcined in muffle to get LiFePO4 by a solid-state reaction. Optimal conditions were: 700°C, N2 ambience, 10h, and Fe/C=1/1.5 (mol). The characterization results showed that the product was irregular particles with size 5-10μm and good dispersion. When discharged in the range of 2.2~4.2V, the initial discharge capacity was 141.4mAh/g at 0.1C, 103.1mAh/g at 1C. The capacity retention was 97.2% after 300 cycles at 1C showing satisfactory stability.

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