Promoted phase transition of titania nanoparticles prepared by a photo-assisted sol-gel method

2002 ◽  
Vol 26 (8) ◽  
pp. 975-977 ◽  
Author(s):  
Haimei Liu ◽  
Wensheng Yang ◽  
Ying Ma ◽  
Yaan Cao ◽  
Jiannian Yao
Keyword(s):  
Phase Transition ◽  
Sol Gel ◽  
Titania Nanoparticles ◽  
Gel Method ◽  
Sol Gel Method

Lanthanide absorption spectral probe in titania nanoparticles synthesized by ultrasonic assistant sol–gel method

2010 ◽  
Vol 71 (7) ◽  
pp. 971-975 ◽  
Author(s):  
Hai-Yan Wang ◽  
Yue-Tao Yang ◽  
Wan-Song Chen ◽  
Yue Wang ◽  
Xiao-Jun Liu ◽  
...  
Keyword(s):  
Sol Gel ◽  
Titania Nanoparticles ◽  
Gel Method ◽  
Sol Gel Method

The Rutile Phase of TiO2/Graphene Films: Sol–Gel Method, Phase Transition, Photocatalytic Properties

2020 ◽  
Vol 207 (1) ◽  
pp. 108-117
Author(s):  
Jin Liu ◽  
Yuanyuan Lv ◽  
Weihu Zhang ◽  
Zhiyong Zhang ◽  
Anyi Wang
Keyword(s):  
Phase Transition ◽  
Sol Gel ◽  
Rutile Phase ◽  
Photocatalytic Properties ◽  
Gel Method ◽  
Sol Gel Method ◽  
Graphene Films

Effect of pH on TiO2 Nanoparticles via Sol-Gel Method

2010 ◽  
Vol 173 ◽  
pp. 184-189 ◽  
Author(s):  
Siti Aida Ibrahim ◽  
Srimala Sreekantan
Keyword(s):  
Sol Gel ◽  
Titania Nanoparticles ◽  
Titanium Tetraisopropoxide ◽  
X Ray Diffraction ◽  
Effect Of Ph ◽  
Gel Method ◽  
Sol Gel Method ◽  
Morphological Studies ◽  
Excellent Photocatalytic Activity ◽  
Sem Micrograph

A series of titania nanoparticles was successfully synthesized via sol gel method using titanium tetraisopropoxide as a precursor. In this paper, data concerning the effect of pH towards the development of TiO2 nanoparticles is reported. The samples were characterised by x-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). XRD results showed the existence of nanocrystalline anatase phases with crystallite size ranging from 7-14 nm. Surface morphological studies obtain from SEM micrograph showed the particles with rodlike shape are rutile while the spherical shapes are anatase in nature. It was also found the pH of the solution affect the agglomeration of the particles. Results of photocatalytic studies exhibits that titania powder prepared at pH 9 has an excellent photocatalytic activity with degradation 74.7% within 60 minutes.

Preparation of Tungsten-Doped VO2 (M) Nanoparticles through Sol-Gel Method and Hydrothermal Synthesis

2014 ◽  
Vol 881-883 ◽  
pp. 960-963 ◽  
Author(s):  
Ji Qi ◽  
Bin Zhao ◽  
Naisen Yu ◽  
Chen Niu ◽  
Guan Gran Sun
Keyword(s):  
Phase Transition ◽  
Vanadium Dioxide ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
New Process ◽  
Scanning Electron

A new process was developed for synthesizing tungsten-doped vanadium dioxide VO2(M) from ammonium metavanadate. The process includes obtaining V2O5by pyrolysing NH4VO3, doping tungsten in V2O5by sol-gel method, and reducing V2O5to VO2(M) with hydrazine by hydrothermal method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) were applied to characterizing the product. The experimental results indicated that tungsten doped VO2(M) nanoparticles were successfully synthesized. The product VO2(M) presents mainly rod-like and block-like morphology. The phase transition temperature decreases with tungsten doped amount increasing, the phase transition takes place over the range from 36.23°C to 62.16°C and the largest enthalpy of the phase transition is 16.24J/g.

Investigation of Interrelation between Particle Size and Phase Transition in the Al2O3-ZrO2 System

2009 ◽  
Vol 6 ◽  
pp. 35-41
Author(s):  
Denis A. Ivanov-Pavlov ◽  
Vladimir G. Konakov ◽  
Elena N. Solovieva ◽  
Viktor M. Ushakov ◽  
Natalia V. Borisova
Keyword(s):  
Phase Transition ◽  
Particle Size ◽  
Sol Gel ◽  
Scanning Calorimetry ◽  
Gel Method ◽  
Sol Gel Method ◽  
Drying Conditions ◽  
Phase Symmetry ◽  
Adsorption Desorption ◽  
Zro2 System

Powder precursors of the Al2O3-ZrO2 system were synthesized by the sol-gel method. Dispersity of the powders depended on synthesis and drying conditions. Differential Scanning Calorimetry, X-Ray diffraction, and method of adsorption–desorption isotherms were used to characterize the interrelations between particle size and phase transition in the Al2O3-ZrO2 system. It was revealed that azeotropic drying under overpressure is quite effective for obtaining well-dispersed powder precursors synthesized by the sol-gel method. In contrast to bulk materials, tetragonal, cubic, and monoclinic phases were found to exist in a wider temperature-composition range. It was shown that the existing phase symmetry in the well-dispersed powders correlates with the crystallite size.

scholarly journals Synthesizing and Evaluating the Photocatalytic and Antibacterial Ability of TiO2/SiO2 Nanocomposite for Silicate Coating

2021 ◽  
Vol 9 ◽  
Author(s):  
Manh-Cuong Le ◽  
Thu-Huong Le ◽  
Thanh-Huyen Bui Thi ◽  
Quang-Dat Nguyen ◽  
Thanh-Ha Do Thi ◽  
...  
Keyword(s):  
Phase Transition ◽  
Surface Area ◽  
Anatase Phase ◽  
Sol Gel ◽  
Photocatalytic Reaction ◽  
Photocatalytic Efficiency ◽  
Silicate Coating ◽  
Gel Method ◽  
Sol Gel Method ◽  
Antibacterial Ability

The TiO2/SiO2 nanocomposite has been synthesized by a sol-gel method and investigated the effect of the SiO2 content (0, 5, 10, 15, 20, and 50%) on the rutile-to-anatase phase transition of TiO2 NPs. In order to increase the photocatalytic efficiency of the nanocomposite and decrease the price of material, the TiO2/SiO2 Nc with content SiO2 of 15% sample is chosen for preparing silicate coating. The efficiency of photocatalytic MB and antibacterial ability in the air of W silicate coating (adding TiO2/SiO2 Nc (15%)) achieve almost 100% for 60 h and 94.35% for 3 h, respectively. While the efficiency of photocatalytic MB and antibacterial ability of WO silicate coating (adding commercial TiO2/SiO2) is about 25–30% for 60 h and 6.02% for 3 h, respectively. The presence of TiO2/SiO2 Nc (15%) with a larger surface area in W silicate coating can provide increased centers for absorption, photocatalytic reaction, and the contact between sample and bacteria lead to enhance the photocatalytic and antibacterial ability of W silicate coating.

scholarly journals Synthesis and characterization of nanoscaled Ba(Ti1-x-ySnxGey)O3 powders and corresponding ceramics

2019 ◽  
Author(s):  
Roberto Köferstein
Keyword(s):  
Phase Transition ◽  
Mixed Oxide ◽  
Sol Gel ◽  
Correlation Spectroscopy ◽  
Germanium Content ◽  
Gel Method ◽  
Sol Gel Method ◽  
Phase Transition Temperatures ◽  
Germanium Concentration

Nanoscaled Ba(Ti1−x−ySnxGey)O3 (BTSG − x − y, x = 0–0.1, y = 0–0.05) powders were synthesized by a sol–gel method (SG) and, as a reference, coarse powders by a mixed-oxide method (MO). The particle sizes were determined by XRD, BET, photon correlation spectroscopy (PCS) and scanning electron microscopy (SEM). The sol–gel method supplied globular particles with narrow fractions in the range between 53 nm and 125 nm. However, from the mixed-oxide method irregularly grown particles were generated with diameters between 300 nm and 700 nm. The SG powders showed a higher sintering activity and, additionally, Sn4+ ions were incorporated at lower temperatures into the BaTiO3 structure. The addition of at least 2 mol% BaGeO3 (BG) resulted in ceramics of densities as high as 96% even at 1050 °C. Furthermore, the cubic ⇆ tetragonal phase transition temperatures were measured by dilatometry, differential thermal analysis (DTA) and dielectric measurements. The temperature and sharpness of the transition are dependent on tin and germanium content. Increasing tin and germanium concentration causes the phase transition temperature to decrease and more diffuse transition.

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