scholarly journals Effect of heat-treatment temperature and zinc addition on magnetostructural and surface properties of manganese nanoferrite prepared by an ecofriendly sol-gel synthesis

2021 ◽  
Author(s):  
Thomas Dippong ◽  
Iosif Grigore Deac ◽  
Mihaela Diana Lazar ◽  
Ioan Petean ◽  
Erika Andrea Levei ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Surface Properties ◽  
Heat Treatment Temperature ◽  
Sol Gel ◽  
Treatment Temperature ◽  
Zinc Addition ◽  
Sol Gel Synthesis

scholarly journals TiO2 and TiO2-Carbon Hybrid Photocatalysts for Diuron Removal from Water

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 457
Author(s):  
Ana Amorós-Pérez ◽  
María Ángeles Lillo-Ródenas ◽  
María del Carmen Román-Martínez ◽  
Patricia García-Muñoz ◽  
Nicolas Keller
Keyword(s):  
Heat Treatment ◽  
Activated Carbon ◽  
Carbon Content ◽  
Heat Treatment Temperature ◽  
Sol Gel ◽  
Spherical Shape ◽  
Hydrothermal Carbonization ◽  
Treatment Temperature ◽  
Simulated Solar Light ◽  
Sol Gel Synthesis

TiO2 and TiO2-activated carbon (AC) photocatalysts have been prepared (by sol-gel synthesis), characterized, and tested in the removal of diuron from water under simulated solar light. The preparation variables of the two series of catalysts are: (i) heat-treatment temperature of bare TiO2 (350, 400, 450 and 500 °C) and (ii) activated carbon content (0.5, 1, 5, and 10 wt.%) in TiO2-AC samples heat-treated at 350 °C. The activated carbon was previously prepared by hydrothermal carbonization of saccharose and has spherical shape. The heat-treatment temperature does not determine the efficiency of TiO2 for diuron photocatalytic degradation, but clearly influences the diuron adsorption capacity. The capacity of TiO2-AC samples for diuron removal increases with the carbon content and it is the result of combined diuron adsorption and photodegradation. Thus, the sample with highest carbon content (10 wt.% nominal) leads to the highest diuron removal. The TiO2-AC photocatalysts have proved to be capable of degrading diuron previously adsorbed in dark conditions, which allows their regeneration.

Preparation of La0.75Sr0.25Cr0.5Mn0.5O3-δ Nanometer Powders by Sol-Gel Method and Research about its Electrochemical Performance

2013 ◽  
Vol 712-715 ◽  
pp. 257-261
Author(s):  
Yin Lin Wu ◽  
Qing Hui Wang ◽  
Ling Wang ◽  
Hai Yan Zhao
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Electrochemical Performance ◽  
Heat Treatment Temperature ◽  
Sol Gel ◽  
Treatment Temperature ◽  
Preparation Process ◽  
Gel Method ◽  
Sol Gel Method ◽  
Ft Ir

The La0.75Sr0.25Cr0.5Mn0.5O3-δnanometer powders were prepared by citric acid sol-gel method.The samples were characterized by DTA, FT-IR, XRD, TEM techniques. The preparation process, morphology of synthesized powders, the best heat-treatment temperature and the electrochemical performance had been studied. The results show that the spherical nanometer powders can be obtained and the best heat-treatment temperature is 800°C. The particle size is about 30nm and Ea is 0.071 eV.

Effects of Heat-Treatment Temperature on the Properties of Negative CTE Eucryptite Ceramics

2010 ◽  
Vol 105-106 ◽  
pp. 123-125 ◽  
Author(s):  
Yong Li ◽  
Qi Hong Wei ◽  
Ling Li ◽  
Chong Hai Wang ◽  
Xiao Li Zhang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Heat Treatment Temperature ◽  
Bending Strength ◽  
Sol Gel ◽  
Negative Thermal Expansion ◽  
Treatment Temperature ◽  
Heat Treated

In this paper, negative thermal expansion coefficient eucryptite powders were prepared by sol-gel method using silica-sol as starting material. The raw blocks were obtained by dry pressing process after the powder was synthesized, and then the raw blocks were heat-treated at 600º, 1150º, 1280º, 1380º, 1420º and 1450°C, respectively. Variations of density, porosity and thermal expansion coefficient at different heat treatment temperatures were investigated. Phase transformation and fracture surface morphology of eucryptite heat-treated at different temperatures, respectively, were observed by XRD and SEM. The results indicate that, with the increasing heat- treatment temperature, the grain size and the bending strength increased, porosity decreased, thermal expansion coefficient decreased continuously. Negative thermal expansion coefficient of -5.3162×10-6~-7.4413×10-6 (0~800°C) was obtained. But when the heat-treatment temperature was more than 1420°C, porosity began to increase, bending strength began to decrease, which were the symbols of over-burning, while the main crystal phase didn’t change.

Load TiO2 or TiO2-N on the Porous Carbon

2012 ◽  
Vol 512-515 ◽  
pp. 1686-1689
Author(s):  
Jie Chen ◽  
Le Fu Mei ◽  
Li Bing Liao
Keyword(s):  
Heat Treatment ◽  
Porous Carbon ◽  
Heat Treatment Temperature ◽  
Treatment Time ◽  
Sol Gel ◽  
Treatment Temperature ◽  
Heat Treatment Time ◽  
Sem Images ◽  
Soaking Time ◽  
Sol Gel Process

In this paper, porous carbon has been used to carry TiO2 and TiO2-N by a sol-gel process. The effect of soaking time, heat treatment temperature, and heat treatment time on the carrying efficiency have been studied. XRD experiments indicated that TiO2 and TiO2-N crystallized in anatase and rutile with the ratio of 3∶2. SEM images showed that island-like TiO2 and TiO2-N particles with diameters in the range of 1-5um, the biggest size is about 10um, were evenly coated on the surface of the porous carbon.

Characterization of Zirconia Sizing Nozzle Modifying Addictives Preparated by Sol-Gel Method

2014 ◽  
Vol 1078 ◽  
pp. 31-35
Author(s):  
Liang Zhao ◽  
Qun Hu Xue ◽  
Dong Hai Ding
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Heat Treatment Temperature ◽  
Sol Gel ◽  
Treatment Temperature ◽  
Composite Powders ◽  
Gel Method ◽  
X Ray

MgO-Al2O3-ZrO2composite powders with 3 kinds of mass ratio were synthesized by sol–gel method using MgCl2·6H2O, AlCl3·6H2O and ZrOCl2·8H2O as starting materials, and NH3·H2O as a precipitant. The composite powders which match with zirconium oxide particle size and evenly distribute can are advantageous to the formation of metastable t-ZrO2and restrain the grain growth as the additive of modified sizing nozzle. Chemical composition, mineral phase, particle size distribution and micro-morphology of the composite powders were investigated by X-ray fluorescence instrument, X-ray diffractometer, laser particle size analyzer and scanning electron microscope. Research showed that under the process that the concentration of MgCl2solution 0.2 mol/L, AlCl3and ZrOCl2solution concentration 0.5 mol/L, the pH controlled between 10 ~ 11, PEG as the surfactant, drying at 70°C±5°C, heat treatment temperature at 800°C for 3h, particle size distribution of MgO-Al2O3-ZrO2composite powders were: d10= 1.28 μm, d50= 4.65μm, d90= 11.13μm (MgO 10%); d10= 1.15μm, d50= 5.80μm, d90= 15.13μm (MgO 15%);d10= 1.21μm, d50= 6.59μm, d90= 16.87μm (MgO 20%). With the rising of heat treatment temperature, the crystallization degree of composite powders increased, at 800 °C a small amount of t - ZrO2precipitated, meanwhile MgO and Al2O3are still in the amorphous phase. The MgO-A12O3-ZrO2composite powders under this condition have high reactivity and uniform distribution.

Effect of Heat Treatment Temperature on Microstructure of Sol-Gel Derived Wollastonite Coating

2012 ◽  
Vol 14 ◽  
pp. 75-79
Author(s):  
Quan He Bao ◽  
Jia Kuo Liu
Keyword(s):  
Heat Treatment ◽  
Titanium Alloys ◽  
Heat Treatment Temperature ◽  
Ph Value ◽  
Sol Gel ◽  
Treatment Temperature ◽  
Amorphous Coating ◽  
Surface Morphologies

Wollastonite coatings on titanium alloys substrates were prepared by sol-gel with different heat treatment temperatures. Microstructures of the specimens were analyzed by XRD. SEM was used to observe surface morphologies of wollastonite coatings. The results show that with the heat treatment temperature increasing, the amorphous coating transforms to a crystalline coating. There are many pores in coatings prepared by sol-gel when heat treatment temperature higher than 900°C with the PH value to 2.5. There are no cracks in coating under such conditions.

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