Preparation, Characterization, and Spectral Studies on Nanocrystalline Anatase TiO2

Reddy, K. Mohan; Reddy, Ch. Venkat; Manorama, Sunkara V.

doi:10.1006/jssc.2001.9090

Cited by 197 publications

(25 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The bandgap of Ն10 nm sized anatase particles has been reported with values ranging between 3.14 and 3.35 eV. 35,36 This corresponds, in average, to a transition energy of 26 170 cm −1 , reachable by two-photon absorption in the blue edge of our pump pulses. Since the pump light is linearly polarized, the two-photon absorption cross section of the particles depends on their relative orientation.…”

Section: High-power Effectsmentioning

confidence: 84%

Ultrafast nonresonant response of TiO2 nanostructured films

Portuondo-Campa

Tortschanoff

Mourik

et al. 2008

The Journal of Chemical Physics

View full text Add to dashboard Cite

We present a detailed study of the nonresonant third-order ultrafast response of TiO(2) nanostructured films, combining a classical heterodyned optical Kerr effect experiment, with two polarization selective Kerr techniques, based on transient lensing and phase modulation effects. The complementarity of these techniques is highlighted and demonstrated with calculations. Different aspects of the experimental results are addressed in detail and, finally, the possibilities of performing experiments on liquid dynamics in the pores of TiO(2) films, are discussed in the light of the present results.

show abstract

Section: High-power Effectsmentioning

confidence: 84%

Ultrafast nonresonant response of TiO2 nanostructured films

Portuondo-Campa

Tortschanoff

Mourik

et al. 2008

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…Nanoscale TiO 2 particle morphology can provide a large specific surface area to increase the photodegradation rate since photocatalytic reactions occur mainly on the TiO 2 photocatalyst surface, which is very sensitive to particle size . TiO 2 in nanopowder form is used mostly as a catalyst, and can be synthesized by many approaches such as inert gas condensation, solution combustion, hydrothermal techniques, solvothermal methods, plasma spray coating, and sol‐gel methods .…”

Section: Introductionmentioning

confidence: 99%

Effect of pressure on TiO₂ crystallization kinetics using in‐situ high‐temperature synchrotron radiation diffraction

2017

View full text Add to dashboard Cite

The phase transformation behavior of TiO 2 sol-gel synthesized nanopowder heated in a sealed quartz capillary from room temperature to 800°C was studied using in-situ synchrotron radiation diffraction (SRD). Sealing of the capillary resulted in an increase in capillary gas pressure with temperature. The pressures inside the sealed capillary were calculated using Gay-Lussac's Law, and they reached 0.36 MPa at 800°C. The as-synthesized material was entirely amorphous at room temperature, with crystalline anatase first appearing by 200°C (24 wt% absolute), then increasing rapidly in concentration to 89 wt% by 300°C and then increasing more slowly to 97 wt% by 800°C, with there being no indication of the anatase-to-rutile transformation up to 800°C. The best estimate of activation energy for the amorphous-to-anatase transformation from the SRD data was 10 (2) kJ/mol, which is much lower than that observed when heating the material under atmospheric pressure in a laboratory XRD experiment, 38(5) kJ/mol. For the experiment under atmospheric pressure, the anatase crystallization temperature was delayed by~200°C, first appearing after heating the sample to 400°C, after which crystalline rutile was first observed after heating to 600°C. The estimated activation energy for the anatase-to-rutile transformation was 120(18) kJ/mol, which agrees with estimates for titania nanofibers heated under atmospheric pressure. Thus, heating the nanopowders material under pressure promoted the amorphous-to-anatase transformation, but retarded the anatase-to-rutile transformation. This behavior is believed to occur in an oxygen-rich environment and interstitial titanium is also expected to form when the material is heated under high gas pressure. This suggests that atmospheric oxygen appears to accelerate the amorphousto-anatase transformation, whereas interstitial titanium inhibits TiO 2 structure relaxation, which is required for the anatase-to-rutile transformation. K E Y W O R D STiO 2 nanopowders, anatase, rutile, sol-gel method, in-situ synchrotron radiation diffraction

show abstract

“…The TiO 2 was always used in environment protection as a result of its eximious light degradability. [22][23][24] In the UV-Vis spectra of MO degraded by different samples, an absorption peak around 463 nm arises and the intensity of the absorption peak reduces with the increasing of photocatalytic activity of additive (Fig. 8).…”

Section: Morphologies and Performance Of Hap/tio 2 Compositementioning

confidence: 96%

“…16 Nano-titania (TiO 2 ) photocatalysts have attracted a great attention due to their non-expensive, nontoxic, biocompatible, and high reactivity for the degradation of organic compounds. [17][18][19][20][21][22][23] A new generation of photocatalysts in near future is expected to possess high degradation efficiency, and set in contact with external pollutant molecules. Therefore, composite photocatalysts were designed by immobilization of TiO 2 on the support materials with large surface area in order to condense diluted pollutants, and enhance the photocatalytic efficiency.…”

Section: Introductionmentioning

confidence: 99%

Preparation and Enhanced Catalyst Effect of Assembled Hydroxylapatite Microsphere Chains

Liu¹,

Wang²,

Luo³

et al. 2012

j nanosci nanotechnol

View full text Add to dashboard Cite

The hydroxyapatite (HAP) assembled microsphere chains with high surface area and large size in length (20-35 microm) were prepared by a facile and efficient cooperation template method. The products were characterized by XRD, TEM, SEM, FT-IR, EDS, BET, etc. The possible mechanism for the formation of HAP assembled microsphere chains was also discussed. In addition, the products were used as carried materials to synthesize HAP/TiO2 (anatase phase) composite catalyst, the bandgap of TiO2 nanomaterials was enlarged. The degradation speed of methyl orange (MO) was increased to 150% when using the composite as catalyst compared with using TiO2 nanoparticles. At the same time, the composite catalyst can be separated and recycled more easily than existing carry materials.

show abstract

Preparation, Characterization, and Spectral Studies on Nanocrystalline Anatase TiO2

Cited by 197 publications

References 27 publications

Ultrafast nonresonant response of TiO2 nanostructured films

Ultrafast nonresonant response of TiO2 nanostructured films

Effect of pressure on TiO₂ crystallization kinetics using in‐situ high‐temperature synchrotron radiation diffraction

Preparation and Enhanced Catalyst Effect of Assembled Hydroxylapatite Microsphere Chains

Contact Info

Product

Resources

About

Preparation, Characterization, and Spectral Studies on Nanocrystalline Anatase TiO2

Cited by 197 publications

References 27 publications

Ultrafast nonresonant response of TiO2 nanostructured films

Ultrafast nonresonant response of TiO2 nanostructured films

Effect of pressure on TiO2 crystallization kinetics using in‐situ high‐temperature synchrotron radiation diffraction

Preparation and Enhanced Catalyst Effect of Assembled Hydroxylapatite Microsphere Chains

Contact Info

Product

Resources

About

Effect of pressure on TiO₂ crystallization kinetics using in‐situ high‐temperature synchrotron radiation diffraction