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 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.

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.

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 Transition of TiO2 Nanotubes: An X-ray Study as a Function of Temperature

2017 ◽  
Vol 121 (44) ◽  
pp. 24871-24876 ◽  
Author(s):  
Francesca A. Scaramuzzo ◽  
Alessandro Dell’Era ◽  
Gabriele Tarquini ◽  
Ruggero Caminiti ◽  
Paolo Ballirano ◽  
...  
Keyword(s):  
Phase Transition ◽  
Tio2 Nanotubes ◽  
X Ray

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.

Electron Microscope study of commensurate-incommensurate phase transition in BaZnGeO4

1990 ◽  
Vol 48 (4) ◽  
pp. 172-173
Author(s):  
Naoki Yamamoto ◽  
Makoto Kikuchi ◽  
Tooru Atake ◽  
Akihiro Hamano ◽  
Yasutoshi Saito
Keyword(s):  
Phase Transition ◽  
Electron Microscope Study ◽  
Room Temperature ◽  
Hexagonal Lattice ◽  
Ferroelectric Materials ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Periodic Arrays ◽  
Modulation Wave Vector

BaZnGeO4 undergoes many phase transitions from I to V phase. The highest temperature phase I has a BaAl2O4 type structure with a hexagonal lattice. Recent X-ray diffraction study showed that the incommensurate (IC) lattice modulation appears along the c axis in the III and IV phases with a period of about 4c, and a commensurate (C) phase with a modulated period of 4c exists between the III and IV phases in the narrow temperature region (—58°C to —47°C on cooling), called the III' phase. The modulations in the IC phases are considered displacive type, but the detailed structures have not been studied. It is also not clear whether the modulation changes into periodic arrays of discommensurations (DC’s) near the III-III' and IV-V phase transition temperature as found in the ferroelectric materials such as Rb2ZnCl4.At room temperature (III phase) satellite reflections were seen around the fundamental reflections in a diffraction pattern (Fig.1) and they aligned along a certain direction deviated from the c* direction, which indicates that the modulation wave vector q tilts from the c* axis. The tilt angle is about 2 degree at room temperature and depends on temperature.

scholarly journals Pressure-induced Jahn-Teller Switch in the Homoleptic Hybrid Perovskite [(CH3)2NH2]Cu(HCOO)3: Orbital Reordering by Unconventional Degrees of Freedom

2021 ◽  
Author(s):  
Rebecca Scatena ◽  
Michał Andrzejewski ◽  
Roger D Johnson ◽  
Piero Macchi
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Coordination Polymer ◽  
Degrees Of Freedom ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hybrid Perovskite ◽  
Jahn Teller

Through in-situ, high-pressure x-ray diffraction experiments we have shown that the homoleptic perovskite-like coordination polymer [(CH3)2NH2]Cu(HCOO)3 undergoes a pressure-induced orbital reordering phase transition above 5.20 GPa. This transition is distinct...

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