scholarly journals Sol-gel Synthesis and Characterization of Lithium and Cerium Codoped Perovskite

2020 ◽  
Vol 9 (1) ◽  
pp. 17-24
Author(s):  
Katarina Mužina ◽  
Marija Tkalčević ◽  
Filip Brleković ◽  
Ivana Katarina Munda ◽  
Vilko Mandić ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Thermal Evolution ◽  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
Calcium Nitrate ◽  
Gravimetric Analysis ◽  
X Ray ◽  
Sol Gel Synthesis ◽  
Thermally Treated

Perovskites are an important group of ceramic materials with a structural formula ABO3 and wide array of potential applications in electronics, superconductors, catalysis, etc. CaTiO3, by which the whole group was named for, is particularly significant due to its use in catalysis, but its photocatalytic activity is limited by a large band gap value (~3.5 eV). A possible solution is the substitution of A and B cations with foreign cations which causes the alteration of properties, including photocatalytic efficiency. The aim of this work was the sol-gel synthesis of lithium and cerium codoped CaTiO3, characterization of the prepared gel and ceramics obtained by its thermal treatment. Samples of codoped perovskite, Ca1-xLixCexTiO3, where x = 0, 0.01, 0.02, 0.03 and 0.04, were prepared and characterized using powder X–ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), differential thermal and thermo-gravimetric analysis (DTA-TGA), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Photocatalytic activity was evaluated through the study of methylene blue photocatalytic degradation. XRD analysis showed that the prepared samples consisted of calcium nitrate and titanium chelate. In accordance with the established thermal evolution path, all samples were thermally treated at 500 °C for 2 hours. Beside perovskite, Ca2Ti2O6 appeared as a secondary phase in all thermally treated samples. SEM analysis of thermally treated samples showed the presence of agglomerates of irregular morphology and the decrease of primary particles size with the increase of dopants concentration. The sample with x=0.04 showed an increased photocatalytic activity.

Study of Pseudoboehmite Synthesis by Sol-Gel Process

2006 ◽  
Vol 45 ◽  
pp. 260-265 ◽  
Author(s):  
Antônio Hortêncio Munhoz Jr. ◽  
Leila Figueiredo de Miranda ◽  
G.N. Uehara
Keyword(s):  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
Ammonium Hydroxide ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Sol Gel Process ◽  
Different Temperatures ◽  
Sol Gel Synthesis

A pseudoboehmite was obtained by sol-gel synthesis using aluminum nitrate as precursor. It was used a 2n full factorial design for studying the effect of the temperature of synthesis, the concentration of ammonium hydroxide, and the radiation dose in the product of sol-gel synthesis. The product of the synthesis was analyzed by scanning electron microscopy, x-ray diffraction of the product (after firing the pseudoboehmite at different temperatures), and it was also analyzed the temperature of endothermic and exothermic transformations using the thermo gravimetric analysis (TG) and differential scanning calorimetry (DSC). The X-ray diffraction data show that α-alumina was obtained at 1100o C.

Two Steps Synthesis of Quaternary Metal Titanate of Ba2NiTi5O13 and Characterization

2011 ◽  
Vol 364 ◽  
pp. 353-358
Author(s):  
Yin Chew Ker ◽  
Abu Bakar Mohamad
Keyword(s):  
Monoclinic Phase ◽  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Thermo Gravimetric ◽  
Pure Phase ◽  
Average Size ◽  
Sol Gel Synthesis

Quaternary metal oxide of Ba2NiTi5O13was synthesized by using two-step sol-gel method. Excess of titanium dioxide obtained from the first step of sol-gel synthesis, were subsequently reacted in second step of sol-gel synthesis in order to produce Ba2NiTi5O13monoclinic phase. Calcination temperature of 900 °C for as long as 8 hours was needed for obtaining pure phase of Ba2NiTi5O13. Homogenous micron sized particles of Ba2NiTi5O13with average size of 0.10 μm and narrow distribution were observed using Scanning Electron Microscopy (SEM). Besides, porous structures can also be seen distributed across the surface of the particles of Ba2NiTi5O13particles. Characterization of monoclinic phase of Ba2NiTi5O13was described based on the investigations of X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) and Thermo Gravimetric Analysis (TGA).

scholarly journals Rapid four-component synthesis of dihydropyrano[2,3-c]pyrazoles using nano-eggshell/Ti(IV) as a highly compatible natural based catalyst

BMC Chemistry ◽  
2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Arefeh Dehghani Tafti ◽  
Bi Bi Fatemeh Mirjalili ◽  
Abdolhamid Bamoniri ◽  
Naeimeh Salehi
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Reaction Times ◽  
Diffraction Field ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solvent Free Conditions ◽  
High Yields ◽  
Work Up

AbstractNano-eggshell/Ti(IV) as a novel naturally based catalyst was prepared, characterized and applied for the synthesis of dihydropyrano[2,3-c]pyrazole derivatives. The characterization of nano-eggshell/Ti(IV) was performed using Fourier Transform Infrared spectroscopy, X-ray Diffraction, Field Emission Scanning Electron Microscopy, Energy-Dispersive X-ray Spectroscopy, and Thermo Gravimetric Analysis. Dihydropyrano[2,3-c]pyrazoles were synthesized in the presence of nano-eggshell/Ti(IV) via a four component reaction of aldehydes, ethyl acetoacetate, malononitrile and hydrazine hydrate at room temperature under solvent free conditions. The principal affairs of this procedure are mild condition, short reaction times, easy work-up, high yields, reusability of the catalyst and the absence of toxic organic solvents.

Study of the Bioactive Behavior of Thermally Treated Modified 58S Bioactive Glass

2008 ◽  
Vol 396-398 ◽  
pp. 131-134 ◽  
Author(s):  
Ourania Menti Goudouri ◽  
Xanthippi Chatzistavrou ◽  
Eleana Kontonasaki ◽  
Nikolaos Kantiranis ◽  
Lambrini Papadopoulou ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Bioactive Glass ◽  
Sol Gel ◽  
Bioactive Glasses ◽  
X Ray ◽  
Characteristic Temperatures ◽  
Calcium Silicates ◽  
Crystal Phases ◽  
Thermally Treated

Thermal treatment of bioactive glasses can affect their microstructure and thus their bioactivity. The aim of this study was the characterization of the thermally treated sol-gel-derived bioactive glass 58S at characteristic temperatures and the dependence of its bioactive behavior on the specific thermal treatment. The thermal behavior of the bioactive glass was studied by thermal analysis (TG/DTA). Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffractometry (XRD) were used for the characterization of the bioactive glass. The bioactive behavior in Simulated Body Fluid (SBF) was examined by Scanning Electron Microscopy (SEM-EDS) and FTIR. The major crystal phases after thermal treatment were Calcium Silicates, Wollastonite and Pseudowollastonite, while all thermally treated samples developed apatite after 48 hours in SBF. A slight enhancement of bioactivity was observed for the samples heated at the temperature range 910-970oC.

scholarly journals Microwave treated sol–gel synthesis and characterization of hybrid ZnS–RGO composites for efficient photodegradation of dyes

2017 ◽  
Vol 41 (4) ◽  
pp. 1723-1735 ◽  
Author(s):  
Lellala Kashinath ◽  
Keerthiraj Namratha ◽  
Shivanna Srikantaswamy ◽  
Ajayan Vinu ◽  
Kullaiah Byrappa
Keyword(s):  
Electron Transfer ◽  
Photocatalytic Activity ◽  
Sol Gel ◽  
Charge Recombination ◽  
Synthesis And Characterization ◽  
Excellent Photocatalytic Activity ◽  
Sol Gel Synthesis

Excellent photocatalytic activity by highly photo-responsive electron transfer from ZnS–RGO, and RGO acts as an electron reservoir and effectively suppresses charge recombination.

Sol-Gel Synthesis and Characterization of Nanocrystalline Bi4Ti3O12 Powders

2014 ◽  
Vol 997 ◽  
pp. 359-362 ◽  
Author(s):  
Chun Hong Ma ◽  
Xue Lin ◽  
Liang Wang ◽  
Yong Sheng Yan
Keyword(s):  
Phase Inversion ◽  
Bismuth Titanate ◽  
Sol Gel ◽  
Tetrabutyl Titanate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sol Gel Synthesis ◽  
Source Materials

Nanocrystalline bismuth titanate (Bi4Ti3O12; BTO) powders were successfully prepared by the sol-gel method, using bismuth nitrate (Bi(NO3)3·5H2O) and tetrabutyl titanate (Ti(OC4H9)4) as source materials, acetic anhydride and ethanediol as solvents. The thermal decomposition and phase inversion process of the gel precursors were studied by using differential thermal analysis (DTA). The crystal structures and microstructures of BTO powders were investigated by using x-ray diffraction (XRD), and transmission electron microscope (TEM). The crystallization of amorphous bismuth titanate has been discussed. The effect of sintering temperature on the structure and morphology of BTO was investigated. At 644 oC and above, BTO powder undergoes a phase transformation from tetragonal to orthorhombic. At 900 oC, the purified orthorhombic BTO nanocrystals were obtained.

scholarly journals Influence of ThO2 on the photocatalytic activity of TiO2

2011 ◽  
Vol 9 (6) ◽  
pp. 1027-1038 ◽  
Author(s):  
Radina Kralchevska ◽  
Maria Milanova ◽  
Petya Kovacheva ◽  
Jovo Kolev ◽  
Georgi Avdeev ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Sol Gel ◽  
Relative Content ◽  
X Ray Diffraction ◽  
Doping Agent ◽  
X Ray ◽  
Decay Products ◽  
Degradation Rate Constant ◽  
Main Factors ◽  
Sol Gel Synthesis

AbstractMicrocomposites consisting of TiO2 (or Ce-doped TiO2) and ThO2 (0.5–2% of the TiO2 mass) are produced by sol-gel synthesis of TiO2 in presence of ThO2. X-ray diffraction study reveals the effects of ThO2 (compared to the ThO2-free TiO2, obtained by the same method) on the anatase interplanar distances, crystallites size and phase composition. The photocatalytic tests in presence of the composites under UV irradiation reveal an increase of the Malachite Green degradation rate constant. The effect depends on the Th relative content, temperature of annealing of the catalyst and addition of other doping agent. The highest photocatalytic activity is observed for TiO2 obtained at 550°C and containing 1% ThO2. The composite exhibits activity in dark, also. The presence of Ce4+ ions is not an obligatory requirement for the realization of the ThO2 effect. The reported results suggest that the radioactivity of the Th and/or its decay products is one of the main factors responsible for the increased photocatalytic activity of TiO2.

Physical and Chemical Properties of Mineral in Soils of Cassava Cropping Area: A Case Study in Chonburi Province

2014 ◽  
Vol 979 ◽  
pp. 440-443
Author(s):  
W. Siriprom ◽  
K. Teanchai ◽  
S. Kongsriprapan ◽  
J. Kaewkhao ◽  
N. Sangwaranatee
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Chemical Properties ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Physical And Chemical ◽  
And Chemical Properties

The chemical and physical properties of topsoil and subsoil which collected from the cassava cropping area in Chonburi Province have been investigated. The characterization of both soil sample were used X-Ray Diffraction (XRD), Energy Dispersive X-Ray Fluorescence (EDXRF) while FTIR used to confirmed the formation of intermolecular bonding and Thermo-Gravimetric Analysis (TGA) used for investigated the crystalline. It was found that, the XRD pattern indicated quartz phase. The chemical composition by XRF reported that the soils samples consist of Si, Al, Ca, Fe, K, Mn, Ti, Cr, Zn, Ag and Cu. and TGA results, noticed that the removal of moisture and organics material.

Sol-Gel Synthesis of Nanocrystalline Ni-Ferrite and Co-Ferrite Redox Materials for Thermochemical Production of Solar Fuels

2014 ◽  
Vol 1675 ◽  
pp. 203-208 ◽  
Author(s):  
Rahul R. Bhosale ◽  
Ivo Alxneit ◽  
Leo L. P. van den Broeke ◽  
Anand Kumar ◽  
Mehak Jilani ◽  
...  
Keyword(s):  
Sol Gel ◽  
Solar Fuels ◽  
Bet Surface Area ◽  
Mixed Solution ◽  
Gel Formation ◽  
Thermochemical Cycles ◽  
X Ray ◽  
Thermogravimetric Analyzer ◽  
Sol Gel Synthesis

ABSTRACTIn this contribution, we report the synthesis and characterization of NixFe3-xO4 and CoxFe3-xO4 redox nanomaterials using sol-gel method. These materials will be used to produce solar fuels such as H2 or syngas from H2O and/or CO2 via solar thermochemical cycles (STCs). For the sol-gel synthesis of ferrites, the Ni, Co, Fe precursor salts were dissolved in ethanol and propylene oxide (PO) was added dropwise to the well mixed solution as a gelation agent to achieve gel formation. Freshly synthesized gels were aged, dried, and calcined by heating them to 600°C in air. The calcined powders were characterized by powder x-ray diffractometer (XRD), BET surface area, as well as scanning (SEM) and transmission (TEM) electron microscopy. Their suitability to be used in STCs for the production of solar fuels was assessed by performing several reduction/re-oxidation cycles using a thermogravimetric analyzer (TGA).

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