Unraveling doping induced anatase–rutile phase transition in TiO2 using electron, X-ray and gamma-ray as spectroscopic probes

2018 ◽  
Vol 20 (45) ◽  
pp. 28699-28711 ◽  
Author(s):  
D. Banerjee ◽  
Santosh K. Gupta ◽  
N. Patra ◽  
Sk Wasim Raja ◽  
N. Pathak ◽  
...  
Keyword(s):  
Phase Transition ◽  
Phase Transformation ◽  
Gamma Ray ◽  
Rutile Phase ◽  
X Ray ◽  
System P ◽  
Spectroscopic Probes ◽  
Mn Doped

The present work reports the microscopic details of anatase (A) to rutile (R) phase transformation in a Mn-doped TiO2 system.

The Effect of Al2O3 and Li2O on the Anatase to Rutile Phase Transformation

2010 ◽  
Vol 297-301 ◽  
pp. 918-923 ◽  
Author(s):  
M.D. Athanassopoulou ◽  
T.G. Argyropoulos ◽  
G.T. Paparoupas ◽  
J.A. Mergos ◽  
C.T. Dervos
Keyword(s):  
Phase Transition ◽  
Phase Transformation ◽  
Transition Rate ◽  
Complex Oxides ◽  
Rutile Phase ◽  
Pure Tio2 ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pseudobinary Systems ◽  
Al2o3 Doping

The utilization of Al2O3 and Li2O as dopants that promote the anatase-to-rutile (A-R) phase transition in TiO2 nanoparticles during calcinations is studied. X-Ray Diffraction and SEM techniques were employed for the evaluation of phase transformation and particle size coarsening in pure TiO2, TiO2-Al2O3 and TiO2-Li2O mixtures. For the Li-Ti-O pseudobinary systems some complex oxides may be formed during phase transformation that occurs at significantly lower temperatures compared to pure TiO2 or TiO2-Al2O3 mixtures. Al2O3 doping in TiO2 only increases the anatase-to-rutile transition rate once the phase transformation has been initiated.

scholarly journals Synthesis and photocatalytic properties of Sn–TiO2 nanomaterials

2020 ◽  
Vol 10 (01n02) ◽  
pp. 2060018
Author(s):  
E. M. Bayan ◽  
T. G. Lupeiko ◽  
L. E. Pustovaya ◽  
M. G. Volkova
Keyword(s):  
Phase Transition ◽  
Thermal Stability ◽  
Sol Gel ◽  
Rutile Phase ◽  
Photocatalytic Properties ◽  
Light Activation ◽  
X Ray ◽  
Tio2 Nanomaterials ◽  
Visible Light Activation ◽  
Thermal Stability Of

Sn-doped TiO2 nanomaterials were synthesized by sol–gel method. It was shown the phase compositions and phase transitions change with the introduction of different tin amounts (0.5–20[Formula: see text]mol.%). X-ray powder diffraction was used to study the effect of different tin amounts on the anatase–rutile phase transition. It was found that the introduction of ions increases the thermal stability of anatase modifications. The material’s photocatalytic activity was studied in reaction with a model pollutant (methylene blue) photodegradation under UV and visible light activation. The best photocatalytic properties were shown for material, which contains 5[Formula: see text]mol.% of Sn.

Unfolding the Anatase-to-Rutile Phase Transition in TiO2 Nanotubes Using X-ray Spectroscopy and Spectromicroscopy

2016 ◽  
Vol 120 (38) ◽  
pp. 22079-22087 ◽  
Author(s):  
Jun Li ◽  
Zhiqiang Wang ◽  
Jian Wang ◽  
Tsun-Kong Sham
Keyword(s):  
Phase Transition ◽  
Tio2 Nanotubes ◽  
Rutile Phase ◽  
X Ray

scholarly journals Tuning Anatase-Rutile Phase Transition Temperature: TiO2/SiO2 Nanoparticles Applied in Dye-Sensitized Solar Cells

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Billy N. Cardoso ◽  
Emerson C. Kohlrausch ◽  
Marina T. Laranjo ◽  
Edilson V. Benvenutti ◽  
Naira M. Balzaretti ◽  
...  
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Surface Area ◽  
Phase Transition Temperature ◽  
Dye Sensitized Solar Cells ◽  
Rutile Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Molar Percent

TiO2/SiO2 nanoparticles with 3, 5, and 10 molar percent of silica, were synthesized by hydrothermal method and characterized by SEM, TEM, N2 adsorption-desorption isotherms, X-ray diffraction, and Raman and UV-Vis spectroscopy. While pristine TiO2 thermally treated at 500°C presents a surface area of 36 m2 g-1 (±10 m2 g-1), TiO2/SiO2 containing 3, 5, and 10 molar percent of silica present surface areas of 93, 124, and 150 m2 g-1 (±10 m2 g-1), respectively. SiO2 is found to form very small amorphous domains well dispersed in the TiO2 matrix. X-ray diffraction and Raman spectroscopy data show that anatase-to-rutile phase transition temperature is delayed by the presence of SiO2, enabling single-anatase phase photoanodes for DSSCs. According to the I×V measurements, photoanodes with 3% of SiO2 result in improved efficiency, which is mainly related to increased surface area and dye loading. In addition, the results suggest a gain in photocurrent related to the passivation of defects by SiO2.

scholarly journals Study on the Phase Transformation Kinetics of Sol-Gel DrivedTiO2Nanoparticles

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
H. Mehranpour ◽  
M. Askari ◽  
M. Sasani Ghamsari ◽  
H. Farzalibeik
Keyword(s):  
Activation Energy ◽  
Phase Transformation ◽  
Sol Gel ◽  
Rutile Phase ◽  
Transformation Kinetics ◽  
X Ray ◽  
Prepared Nanoparticles ◽  
Phase Transformation Kinetics ◽  
Diffusion Controlled ◽  
Kinetics Of

Titanium dioxide nanopowders were synthesized by the diffusion controlled sol-gel process (LaMer model) and characterized by DTA-TG, XRD, and SEM. The preparedTiO2nanoparticles have uniform size and morphology, and the phase transformation kinetics of obtained material was studied by interpretation of the X-ray diffraction patterns peaks on the base of Avrami equation. The stating point of anatase-rutile phase transformation temperature in the prepared nanoparticles was found between 100 and200°C. A decreasing trend on the intensity of X-ray peaks of anatase phase was observed up to600°Cwhen the presence of the rutile phase became predominant. Results indicated that the transition kinetics of the diffusion controlled prepared nanoparticles was begun at low temperature, and it can be concluded that the nucleation and growth sites in these particles were more than other. However, it has been found that the nucleation activation energy of rutile phase was 20 kj/mol, and it is the lowest reported activation energy.

Effect of Oxidation on Phase Transformation in Ti-Bearing Blast Furnace Slag

2013 ◽  
Vol 641-642 ◽  
pp. 363-366 ◽  
Author(s):  
Wu Zhang ◽  
Li Zhang ◽  
Nai Xiang Feng
Keyword(s):  
Phase Transformation ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Glass Phase ◽  
Perovskite Phase ◽  
Rutile Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Furnace Slag ◽  
Scanning Electron

Abstract. Effect of oxidation on phase transformation in Ti-bearing blast furnace slag is studied. The slag is analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM), EDX and metallographic microscope. The experiment results indelicate that the phase composition of the oxidized slag is simpler which are only rutile and glass phase. The titanaugite, Ti-rich diopside and perovskite phase are vanished and most of the Ti components were enriched in the rutile phase.

Study on the Structure and Phase Transition of Sm Substituted BiFeO3 Nanoparticles

2011 ◽  
Vol 418-420 ◽  
pp. 278-281
Author(s):  
Yu Xia Sun ◽  
Xing Wen Zhang ◽  
Hong Ri Liu
Keyword(s):  
Phase Transition ◽  
Phase Transformation ◽  
Annealing Temperature ◽  
Raw Materials ◽  
Structural Phase ◽  
Phase Transformation Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bifeo3 Nanoparticles ◽  
Substitution Ratio

Pure and Sm substituted BiFeO3 nanoparticles were prepared by a coprecipitate method using Bi(NO3)3•5H2O and Fe(NO3)•9H2O as raw materials. X-ray diffraction pattern indicates that perovskite structural BiFeO3 can be obtained using 0.02 molar precursor precipitate by annealing at 550 °C. A structural phase transition deduced by Sm substitution was observed. SEM results showed that the size of BiFeO3 increases with annealing temperature and substitution ratio. DTA results showed that the phase transformation temperature decreases with Sm substitution ratio.

Structural and Thermal Studies of Titanium Dioxide Gel Modified with Anatase Isostructural Zircon Silicate

2018 ◽  
Vol 930 ◽  
pp. 73-78
Author(s):  
Eduardo Felipe de Carli ◽  
Natali Amarante da Cruz ◽  
Hiana Muniz Garcia ◽  
Jusinei Meireles Stropa ◽  
Lis Regiane Vizolli Favarin ◽  
...  
Keyword(s):  
Phase Transition ◽  
Titanium Dioxide ◽  
Rietveld Method ◽  
Anatase Phase ◽  
Sol Gel ◽  
Thermal Studies ◽  
Rutile Phase ◽  
Structural Rearrangements ◽  
X Ray Diffraction ◽  
X Ray

Important changes in anatase crystal structure are responsible for the consequent anatase-to-rutile phase transition in titanium dioxide powders. In order to investigate several structural rearrangements occurring in anatase phase obtained by hydrolysis-based method such as Sol-Gel method the X-ray diffraction techniques followed by Rietveld method seems to better approach. Several alterations in anatase lattice parameters can occur by doping insertion and the investigation of isostructural zircon silicate can provide interesting ones. In the present paper, the monitoring of anatase structure reordering and the consequent anatase-to-rutile phase transition along the thermal treatment up to higher temperatures were monitored carrying out DSC and XRD characterizations. The insertion of 6 mol% of zircon silicate leads to the fully anatase stabilization up to 900 °C due the control of ordering process, even that a continuous increasing in anatase tetragonality is present during the entire process. We can conclude the reconstructive anatase-to-rutile phase transition is delayed to very higher temperatures can consequence of more stable cross-linked metal oxide bond in anatase phase.

Modification of the phase transition temperatures in titania doped with various cations

1997 ◽  
Vol 12 (2) ◽  
pp. 439-443 ◽  
Author(s):  
R. Rodríguez-Talavera ◽  
S. Vargas ◽  
R. Arroyo-Murillo ◽  
R. Montiel-Campos ◽  
E. Haro-Poniatowski
Keyword(s):  
Phase Transition ◽  
Anatase Phase ◽  
Sol Gel ◽  
Rutile Phase ◽  
Transition Temperatures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Phase Transition Temperatures ◽  
Gel Technique ◽  
Almost All

Titania matrices prepared by a sol-gel technique were doped with several cations (La, Zn, Al, K, Na, Ca, Ba, and Co). The effect of the dopants on the thermal and structural properties of the materials is analyzed. The dopant concentration was 2% mol with respect to titanium, and in all cases the same anion (nitrate) was used. The transition temperatures from amorphous to anatase and from anatase to rutile were measured using x-ray diffraction. The amorphous-anatase transition is independent, for almost all samples, of the type of dopant used; however, the anatase-to-rutile phase transition depends strongly on the kind of cation. This means that the temperature range where the anatase phase exists can be controlled by choosing the appropriate dopant. We have found a correlation between the anatase-rutile phase transition temperature and the radius of the cations and their electric charge.

Phase transformation studies on anthranilic acid by thermal analysis, infrared absorption, and X-ray diffraction methods

1976 ◽  
Vol 54 (15) ◽  
pp. 2509-2513 ◽  
Author(s):  
Krishnan Rajeshwar ◽  
Etalo A. Secco
Keyword(s):  
Phase Transition ◽  
Thermal Analysis ◽  
Phase Transformation ◽  
Infrared Absorption ◽  
Anthranilic Acid ◽  
X Ray Diffraction ◽  
X Ray

The kinetic, structural, and thermodynamic aspects of the phase transition, orthorhombic I → orthorhombic II, in anthranilic acid (o-C6H4NH2COOH) were investigated by thermal analysis, infrared absorption, and X-ray diffraction methods.

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