Anatase Rutile Reduction

Carbothermic Reduction of Anatase and Rutile. | Request PDF

The carbothermic reduction of anatase and rutile to TiC was investigated using a combination of thermogravimetric analysis and X-ray diffraction. Samples premilled for 50h prior to heat treatment ...

Preparation of Titanium Dioxide Anatase Pigment from ...

Preparation of Titanium Dioxide Anatase Pigment from Rosetta Ilmenite Concentrate via the Sulfate Route ( 131 ) ABSTRACT KEYWORDS Preparation of Titanium Dioxide Anatase Pigment from Rosetta Ilmenite Concentrate via the Sulfate Route Abdelfattah,N.A. E.mail:[email protected] Ion Beam Emittance, Pentode Extraction System, First and Second

Why is anatase a better photocatalyst than rutile? - Model ...

Feb 10, 2014· Anatase exhibits an indirect band gap that is smaller than its direct band gap. For rutile, on the other hand, its fundamental band gap is either direct or its indirect band gap is very similar to its direct band gap. Semiconductors with indirect band gap generally exhibit longer charge carrier life ...

Enhanced photocatalytic Fe reduction with H O TiO anatase ...

KARUNAKARAN et al.:PHOTOCATALYTIC REDUCTION OF Fe3+ BY TiO 2 ANATASE/RUTILE BLEND 1077 outer-irradiation systems, respectively. TiO 2-coated WO 3 particles are found to be a better photocatalyst for the oxidation of water with Fe3+ ion as the …

Transient Absorption Spectroscopy of Anatase and Rutile ...

Rutile exhibited up to 10 times slower recombination kinetics than anatase. Efficient, irreversible hole scavenging by alcohols was present in mesoporous anatase alone, resulting in the generation of long-lived electrons (τ ≈ 0.7 s) which, upon the addition of the dye reduction target resazurin, enabled efficient electron transfer (τ ≈ 3 ms).

Rutile titanium dioxide prepared by hydrogen reduction of ...

An important factor to improve the photocatalytic activity of rutile TiO 2 is H 2 reduction treatment. H 2-reduced rutile TiO 2 outperforms anatase-rich TiO 2 because of the wider absorption range caused by its smaller band gap (3.0 eV for rutile and 3.2 eV for anatase). The apparent quantum efficiency for H 2 evolution of H 2-reduced rutile ...

Effect of Raw Material Characteristics on the Carbothermal ...

2(II) powder which has a 15% rutile phase structure and an 85% anatase phase structure with an average particle size of 45nm had undergone phase transformation from the anatase phase structure to the rutile phase structure before a carbothermal reduction occurs by the carbon black as in the case of the TiO 2(I) powder.

Photocatalytic CO 2 reduction with H 2O on TiO 2 ...

The production of CO and CH 4 from CO 2 photoreduction was remarkably enhanced on defective anatase and brookite TiO 2 (up to 10-fold enhancement) as compared to the defect-free surfaces. Defective brookite was photocatalytically more active than anatase and rutile, probably because of a lower formation energy of V O on brookite.

Catalytic reduction of nitrate in water over Pd-Cu/TiO2 ...

In this study, we prepared TiO 2-supported Pd-Cu catalysts of different anatase/rutile phase compositions, which were used in a nitrate reduction in water.It was shown that the catalysts containing a greater anatase phase composition had higher catalytic performance.

SYNTHESIS OF MESOPOROUS TITANIA IN RUTILE PHASE …

that no anatase-rutile transformation was detected for 3 h of calcinations at 970oC (Figure 1). The Figure 2 shows the XRD patterns obtained for calcinations at 980oC, considering different periods. The XRD patterns show that the rutile phase starts to form only at 980oC. After 4 hours, rutile …

Enhanced Photoelectrochemical Performance from …

fabricate the FTO/anatase/rutile TiO 2 structure, 5, 10, and 20 nm thicknesses of TiO 2 films are deposited onto the FTO substrates by atomic layer deposition (ALD) before the hydrothermal growth of rutile TiO 2 nanorods (labeled 5AR, 10AR and 20AR, where A, R, and the number correspond to anatase films, rutile nanorods, and anatase film ...

Phase-pure TiO2 nanoparticles: anatase, brookite and ...

We report on the synthesis of phase-pure TiO 2 nanoparticles in anatase, rutile and brookite structures, using amorphous titania as a common starting material. Phase formation was achieved by hydrothermal treatment at elevated temperatures with the appropriate reactants.

Production of Titanium Nitride by Carbothermic Reduction ...

Reduction of anatase started just below 900°C whilst rutile underwent reduction below 800°C. TGA results showed that the anatase reduction was more complex than the rutile reduction with several stages evident between 880 and 1000°C in the anatase sample whilst only two steps were observed for rutile.

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Photocatalytic CO2 Reduction with H2O on TiO2 Nanocrystals ...

The production of CO and CH 4 from CO 2 photoreduction was remarkably enhanced on defective anatase and brookite TiO 2 (up to 10-fold enhancement) as compared to the defect-free surfaces. Defective brookite was photocatalytically more active than anatase and rutile, probably because of a lower formation energy of V O on brookite.

Photocatalysis - Wikipedia

As an efficient absorber in the UV range, titanium dioxide nanoparticles in the anatase and rutile phases are able to generate excitons by promoting electrons across the band gap. The electrons and holes react with the surrounding water vapor to produce hydroxyl radicals and protons.

Structural Aspects of Anatase to Rutile Phase Transition ...

In temperatures close to anatase‐to‐rutile phase transition, the both vectors a and c of anatase phase for pure titanium dioxide samples start to reduce, marking the initial collapse of anatase phase, which will no longer be present at 800°C.

catalysts and rutile) nanoparticles as efficient ...

in Fig.S6b and S6c, the as-prepared anatase or rutile showed the best photocatalytic activity the calcinated and fluorinated anatase or results showed that surface fluorination photocatalytic performance of brookite TiO2 while reduced the performance of anatase and TiO2.

Review of the anatase to rutile phase transformation ...

Abstract. Titanium dioxide, TiO 2, is an important photocatalytic material that exists as two main polymorphs, anatase and rutile.The presence of either or both of these phases impacts on the photocatalytic performance of the material. The present work reviews the anatase to rutile …

The Interaction of V2O5 with TiO2(Anatase): The Active ...

reduction kinetics of the V205/Ti02(anatase) samples and the unsupported V205 were examined with the temperature programmed reduction method. The TPR experiments reveal that the surface vanadia species and V205 crystallites supported on the Ti02(anatase) surface reduce more readily

Photocatalytic Reduction of Uranyl Ions over Anatase and ...

Photocatalytic Reduction of Uranyl Ions over Anatase and Rutile Nanostructured TiO2. ... A series of TiO2 samples with different anatase-to-rutile ratios was prepared by calcination, and the roles ...

Pd Loaded TiO2 Nanotubes for the Effective ... - SpringerLink

Titania nanotubes Anatase Rutile Morphology Palladium Catalysis and reduction Electronic supplementary material The online version of this article (doi: 10.1007/s10562-015-1663-8 ) contains supplementary material, which is available to authorized users.

Preparation and Comparison of Supported Gold Nanocatalysts ...

mixture (P25) of anatase and rutile. To more deeply understand the reaction mechanism associated with gold nanoparticles, it is useful to study the support effect induced by allotropic forms. Titanium dioxide is a good candidate be-cause it exists in three different allotropic forms: anatase, brookite, and rutile.

Titanium dioxide (TiO ) Nanoparticles - XRD Analyses – An ...

anatase, brookite and rutile forms. These phases are characterized with high refractive index (anatase = 2.488, rutile = 2.609, brookite = 2.583), low absorption and low dispersion in visible and near-infrared spectral regions, high chemical and thermal stabilities [3].

Black and white anatase, rutile and mixed forms: band ...

Black and white anatase, rutile and mixed forms: band-edges and photocatalytic activity . ... By optimizing the thermal reduction conditions of black anatase/rutile junctions the H 2 production can be significantly increased. About. Cited by. Related. Back to tab navigation.

A Patterned TiO2(Anatase)/TiO2(Rutile) Bilayer-Type ...

Coupling of anatase and rutile TiO 2 in a bilayer form significantly increases photocatalytic activity relative to the individual components. Reducing the dimensions of the junction to the charge-separation distance is of importance in increasing this activity.

Photocatalytic Reduction of Benzophenone on TiO2: Effect ...

Photocatalytic Reduction of Benzophenone on TiO 2: Effect of Preparation Method and Reaction Conditions 135 The liquid phase photochemical reduction of benzophe-none in N 2 atmosphere was carried under UV light irradiation. Figure 3 shows the chromatogram after 45 min of reaction

The structure and catalytic activity of anatase and rutile ...

Mar 14, 2011· Under the SCR reaction conditions, Mn(+3) species on anatase are oxidized to Mn(+4) species, inserting in the surface of anatase and promoting the anatase-to-rutile transformation in the surface layers of the anatase support.

Phase Characterization of TiO Powder by XRD and TEM

is widely nominated for three main phases of rutile, anatase and brookite (Kim et al., 2005). Among them, the TiO 2 exists mostly as rutile and anatase phases which both of them have the tetragonal structures. However, rutile is a high-temperature stable phase and has an optical energy band gap of 3.0 eV (415 nm), anatase is formed at a lower

Study of ethanol reactions on H2 reduced Au/TiO2 anatase ...

AbstractThe effect of Au particle size and loading (over TiO2 anatase and rutile) on the reaction selectivity and conversion of ethanol has been studied using temperature programmed desorption. The addition of Au onto TiO2 had three main effects on the reaction. First, a gradual decrease is observed in the reaction selectivity of the dehydration (to ethylene) in favor of dehydrogenation (to ...

Comparison of the reduction of metal oxide surfaces: TiO2 ...

Reduction of stoichiometric metal oxide can be reached by two processes: oxygen vacancies or hydrogenation. We present DFT-GGA periodic calculations for the O vacancies in the bulk and selected slabs of TiO 2-rutile, TiO 2-anatase, and SnO 2-rutile as well as their hydrogenation.We focus on the comparison between these structures.

TiO2 on Gold Nanostars Enhances Photocatalytic Water ...

TiO 2 on Gold Nanostars Enhances Photocatalytic Water Reduction in the Near-Infrared Regime. Supriya Atta. Supriya Atta. Affiliations. Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA ... P25 is a 3:1 mixture of anatase and rutile TiO 2, and the rate enhancement observed in P25 ...