scholarly journals Tuning the Photo-Luminescence Properties of WO3 Layers by the Adjustment of Layer Formation Conditions

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2814 ◽  
Author(s):  
Milda Petruleviciene ◽  
Jurga Juodkazyte ◽  
Maliha Parvin ◽  
Alla Tereshchenko ◽  
Simonas Ramanavicius ◽  
...  
Keyword(s):  
Sol Gel ◽  
Photo Luminescence ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Photoluminescence Decay ◽  
Formation Conditions ◽  
Sol Gel Synthesis ◽  
Time Resolved Photoluminescence ◽  
Dipping Time

In this research we have applied sol-gel synthesis for the deposition of tungsten (VI) oxide (WO3) layers using two different reductants (ethanol and propanol) and applying different dipping times. WO3 samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared spectroscopy (FTIR), photoluminescence (PL) and time-resolved photoluminescence decay methods. Photoelectrochemical (PEC) behaviour of synthesized coatings was investigated using cyclic voltammetry in the dark and under illumination. Formation of different structures in differently prepared samples was revealed and significant differences in the PL spectra and PEC performance of the samples were observed. The results showed that reductant used in the synthesis and dipping time strongly influenced photo-electrochemical properties of the coatings. Correlation between the morphology, PL and PEC behaviour has been explained.

scholarly journals Effect of Polymers (PEG and PVP) on Sol-Gel Synthesis of Microsized Zinc Oxide

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Thilagavathi Thirugnanam
Keyword(s):  
Sol Gel ◽  
Cost Effective ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural Modifications ◽  
Phase Pure ◽  
Sol Gel Synthesis ◽  
Polyethylene Glycol 6000 ◽  
Granular Morphology ◽  
Scanning Electron

Fibers irregular and seed-like microcrystalline ZnO were synthesized by using a cost-effective and low temperature aqueous sol-gel method. Various polymers, namely, polyethylene glycol 6000 (PEG 6000) and polyvinyl pyrrolidone (PVP), were used as structure directing agents. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The X-ray diffraction pattern revealed the formation of phase-pure ZnO micropowders. It is observed that the polymers play an important role in modifying the surface morphology and the size of the crystallites. A compact granular morphology is observed for the ZnO samples without polymer. The samples exhibit microparticles of size 100 nm for PVP and for PEG-mediated growth, whereas microporous corrugated morphology is observed for added PEG-mediated micropowder. FTIR study is used to confirm the structural modifications occurring in the polymers.

scholarly journals Sol-Gel Synthesis, X-Ray Diffraction Studies, and Electric Conductivity of Sodium Europium Silicate

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ekaterina V. Borisova ◽  
Alexey V. Ignatov ◽  
Eugeni I. Get'man ◽  
Stanislav N. Loboda ◽  
Lyudmyla I. Ardanova ◽  
...  
Keyword(s):  
Activation Energy ◽  
Electric Conductivity ◽  
Rietveld Refinement ◽  
Sol Gel ◽  
Apatite Structure ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Sol Gel Synthesis

Sodium europium silicate, NaEu9(SiO4)6O2, with apatite structure has been obtained and studied using X-ray diffraction and SEM. It has been shown that sodium sublimation does not take place upon synthesis by the sol-gel method. Rietveld refinement has revealed that sodium atoms are ordered and occupy the 4f position. O(4) atoms not related to silicate ions are placed at the centers of Eu(2) triangles. DC and AC electric conductivity and activation energy have been determined for the compound studied.

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.

Homogeneity in the Polyether Alkoxide Sol‐Gel Synthesis of YBa2Cu3O7-δ

1994 ◽  
Vol 346 ◽  
Author(s):  
Carol S. Houk ◽  
Gary A. Burgoine ◽  
Catherine J. Page
Keyword(s):  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Mapping Techniques ◽  
Starting Solutions ◽  
Average Size ◽  
Sol Gel Synthesis ◽  
Elemental Maps

ABSTRACTWe have investigated the homogeneity of sol‐gel derived YBa2Cu307‐s from the solution phase to the final product using transmission electron microscopy (TEM), x‐ray diffraction (XRD), and Energy Dispersive X‐ray (EDX) lateral mapping techniques. The starting solutions contain stoichiometric amounts of the metal 2‐(2‐methoxyethoxy)ethoxide components in 2‐(2‐methoxyethoxy)ethanol and appear to be homogeneous by TEM with a uniform distribution of particles having an average size of less than 40 â. Through elemental mapping we see elemental segregation in the high temperature (950 °C) products, which are orthorhombic by XRD. In elemental maps of gel samples fired to 700 °C, which are tetragonal by XRD, we also see elemental inhomogeneity within particles and phase zoning in maps of products from finely ground gels. A comparison of elemental maps and x‐ray diffraction patterns of the products from gel processing and conventional solid state processing is made.

Sol-Gel Synthesis and Characterizations of LiCF3SO3-CeO2 Solid Composite Electrolytes

2010 ◽  
Vol 129-131 ◽  
pp. 506-510 ◽  
Author(s):  
N.A. Dzulkurnain ◽  
N.S. Mohamed
Keyword(s):  
Sol Gel ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Lithium Triflate ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
X Ray ◽  
Composite Solid Electrolyte ◽  
Sol Gel Synthesis ◽  
Composite Solid

Composite solid electrolyte systems composed of different compositions of lithium triflate (LiCF3SO3) as host, and cerium oxide (CeO2) as dispersoid were prepared using sol-gel method. The electrical, structural and morphological properties of the composite solid electrolytes were investigated using impedance spectroscopy (IS), X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM). Maximum room temperature conductivity was obtained for the system of 60 mol % LiCF3SO3 – 40 mol % CeO2.

Sol–gel synthesis, structural and electrical properties of Li2CoSiO4 cathode material

2014 ◽  
Vol 07 (06) ◽  
pp. 1440001 ◽  
Author(s):  
Michał Świętosławski ◽  
Marcin Molenda ◽  
Piotr Natkański ◽  
Piotr Kuśtrowski ◽  
Roman Dziembaj ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Sol Gel ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Structural And Electrical Properties ◽  
Potential Alternative ◽  
Sol Gel Synthesis ◽  
First Time

Polyanionic cathode materials for lithium-ion batteries start to be considered as potential alternative for layered oxide materials. Among them, Li 2 CoSiO 4, characterized by outstanding capacity and working voltage, seems to be an interesting substitute for LiFePO 4 and related systems. In this work, structural and electrical investigations of Li 2 CoSiO 4 obtained by sol–gel synthesis were presented. Thermal decomposition of gel precursor was studied using EGA (FTIR)-TGA method. Chemical composition of the obtained material was confirmed using X-ray diffraction and energy-dispersive X-ray spectroscopy. The morphology of β- Li 2 CoSiO 4 was studied using transmission electron microscopy. High temperature electrical conductivity of Li 2 CoSiO 4 was measured for the first time. Activation energies of the electrical conductivity of two Li 2 CoSiO 4 polymorphs (β and γ) were determined. The room temperature electrical conductivity of those materials was estimated as well.

Morphology and Phase Composition of Sol-Gel Derived Aluminum Borate Nanowhiskers

2015 ◽  
Vol 659 ◽  
pp. 121-126 ◽  
Author(s):  
Pat Sooksaen
Keyword(s):  
Fourier Transform ◽  
Phase Composition ◽  
Sol Gel ◽  
Molar Ratio ◽  
Aluminum Borate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Higher Temperature ◽  
Sol Gel Synthesis ◽  
Scanning Electron

Aluminium borate nanowhiskers with varying aspect ratio were synthesized via sol–gel synthesis. The morphology of aluminum borate (Al4B2O9 and Al18B4O33) nanowhiskers could be controlled by varying the aluminum to boron (Al:B) molar ratio in the sol–gel derived precursors. Sintering temperatures (850 and 1100°C) and sintering times (4 and 32 hours) also affected the phase composition and size of the nanowhiskers. Citric acid was also added in the sol–gel derived precursors as a surface stabilizer for obtaining uniform finely dispersed nanostructures. Fine nanowhiskers were obtained by the calcination at 850°C, whereas higher temperature of 1100°C led to thicker and longer nanowhiskers and became rod-like crystals. The morphology and phase composition were investigated by field emission scanning electron microscope and X-ray diffraction. Chemical bond vibrations in the synthesized nanowhiskers were investigated by Fourier-transform infrared spectroscopy.

scholarly journals Structural and Microstructural Properties of Systems Based on Bi0.5Na0.5TiO3

Revista EIA ◽  
2020 ◽  
Vol 17 (33) ◽  
Author(s):  
Marcela Revelo Castro ◽  
Sonia Gaona Jurado ◽  
Claudia Fernanda Villaquiran Raigoza
Keyword(s):  
Piezoelectric Materials ◽  
Sol Gel ◽  
Structural Complexity ◽  
Microstructural Properties ◽  
X Ray Diffraction ◽  
Ceramic Powders ◽  
Scanning Electronic Microscopy ◽  
X Ray ◽  
Infrared And Raman Spectroscopy ◽  
Sol Gel Synthesis

Perovskites based on bismuth sodium titanates, Bi0.5Na0.5TiO3 (BNT), are incorporated into lead-free piezoelectric materials. Although BNT was discovered five decades ago, many aspects such as the structural complexity and the modifications produced when it is combined with other perovskites are not clearly understood. We studied the structural and microstructural properties of BNT upon addition of BaTiO3 (BT) and SrTiO3 (ST) during sol-gel synthesis. We characterized the ceramic powders by infrared and Raman spectroscopy, X-ray diffraction and scanning electronic microscopy. The addition of BT/ST modified the bonds, generating coexistence and phase transition and confirmed the existence of a morphotropic phase boundary. 

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