anatase rutile reduction


Rutile TiO2 Supported Pt as Stable Electrocatalyst for ...

2016-9-14 · The platinum nanoparticles deposited on rutile TiO 2-800 exhibit higher oxygen reduction reaction (ORR) activity and better fuel cell performance compared to Pt supported on anatase TiO 2. The structural effect, dispersion of platinum nanoparticles, and oxidation states are studied by powder X-ray diffraction (PXRD), transmission electron ...Nb-Doped TiO2 Photocatalysts Used to Reduction of CO2 …2018-4-2 · Considering the change in values of cell parameters (a, b, c) of anatase and rutile crystals that was caused by the replacement of Ti for Nb and comparing them to the Nb–TiO 2 photocatalyst 0.0% (w/w), which does not contain Nb, it was observed that there is a decrease in cell volume ranging from 133.74 Å 3 to 133.53 Å 3 in Nb–TiO 2 0.5 Nb% (w/w) and Nb–TiO 2 …

Nanostructured TiO2 anatase-rutile-carbon solid coating ...

2019-2-13 · Rutile has a smaller bandgap than anatase, but rutile is more challenging to produce as nanoparticles 13. Rutile-anatase heterojunctions have …One-Dimensional Mesoporous Anatase-TiO2/Rutile …2020-7-19 · Based on this mechanism, the photo-excited electrons from the CB of rutile would respectively flow to anatase and ZnTiO 3, while both the holes from VB of anatase and ZnTiO 3 will arrive at rutile. Hence, the separated electrons are …

Differences in the selective reduction mechanism of 4 ...

Ru/TiO2 catalysts exhibit excellent catalytic performance for selective reduction of 4-nitroacetophenone to 4-aminoacetophenone at normal temperature and atmospheric hydrogen pressure. Moreover, 99.9% selectivity to 4-aminoacetophenone can be obtained over 2.7 wt% Ru/TiO2(anatase) catalyst even in a relativeBand restructuring of ordered/disordered blue TiO2 for ...Herein, we present a noble metal-free visible light photocatalyst, blue TiO 2, with type-II band-aligned ordered anatase/disordered rutile structures via phase-selective reduction with alkali metals. The changed band alignment in this heterostructure was identified by absorption and ultraviolet photoemission spectroscopy, which was further ...

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

2005-5-20 · 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.Understanding the anatase–rutile phase junction in …Understanding the anatase–rutile phase junction in charge separation and transfer in a TiO2 electrode for photoelectrochemical water splitting† Ailong Li,ab Zhiliang Wang,ab Heng Yin,ab Shengyang Wang,ab Pengli Yan,ab Baokun Huang,a Xiuli Wang,a Rengui Li,a Xu Zong,a Hongxian Han*ac and Can Li*ac New insight into junction-based designs for efficient charge …

Nanostructured TiO2 anatase-rutile-carbon solid coating ...

2019-2-13 · Rutile has a smaller bandgap than anatase, but rutile is more challenging to produce as nanoparticles 13. Rutile-anatase heterojunctions have …Raman spectra of (a) anatase, and (b) rutile TiO 2 ...2022-2-7 · The cell parameters of anatase were obtained to be a/b = 3.7794 Å and c = 9.4984 Å, and for rutile a/b = 4.5847 Å and c = 2.9557 Å (from refinement in Figure S1 in SI). The anatase showed a ...

Carbothermic reduction of anatase and rutile

2005-3-22 · The carbothermic reduction of anatase and rutile to TiC was investigated using a combination of thermogravimetric analysis and X-ray diffraction. Samples premilled for 50 h prior to heat treatment showed a much greater extent of …Carbothermic Reduction of Anatase and Rutile. | Request …The reduction of rutile started at ∼830°C whilst anatase underwent reduction at 870°C. The initial identified products were Ti5O9 and Ti4O7 with the latter being the last apparently stable ...

Hydrogenation of TiO2 nanosheets and nanoparticles: …

2021-10-1 · When it comes to the reduction of nanoparticles, orientation-relative anisotropic disorder has been observed. It is found that the preferable disordered surface is along {001} for anatase, {100} for brookite and {001} for rutile, causing anisotropic stress deformation.Phase Characterization of TiO Powder by XRD and TEM2010-3-4 · Kasetsart J. (Nat. Sci.) 42 : 357 - 361 (2008) Phase Characterization of TiO 2 Powder by XRD and TEM Kheamrutai Thamaphat 1*, Pichet Limsuwan1 and Boonlaer Ngotawornchai2 ABSTRACT In this study, the commercial TiO 2 nanopowder and micropowder of anatase phase and rutile phase have been characterized by x-ray diffraction (XRD) and transmission electron …

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 ...Selective Catalytic Reduction of NO Using Phase-Pure ...We demonstrate a facile selective synthesis of phase-pure anatase, rutile, and brookite nanocrystal polymorphs of titania (TiO 2) using a benign hydrothermal treatment of an industrial grade TiOSO 4 precursor. Acetic acid (CH 3 COOH) is used for the synthesis of anatase, glycolic acid (HOCH 2 COOH) is used for rutile, and both glycolic acid and ammonium hydroxide (NH …

Effect of elemental iron on the carbothermic reduction of ...

2005-5-31 · Fig. 1 shows the mass loss for anatase and rutile systems both with and without iron. The mass losses up to ∼800 °C in all the systems is related to adsorbed gas, as shown elsewhere, with XRD showing no evidence for reduction in any system after heating to 800. °C.. Download : Download full-size image Fig. 1.. Mass loss as a function of temperature for mixtures of rutile …Understanding the surface reduction of nano rutile and ...2020-1-1 · Though black titania has been widely investigated, the influence of crystal phase during the reduction process remains unknown. In the present study, we found that the rutile phase is preferentially reduced over anatase from detailed experimental investigations and a comprehensive understanding of selective breaking of Ti-O bonds in surfaced TiO 6 …

Structural Aspects of Anatase to Rutile Phase Transition ...

2016-11-17 · It was noticed that the crystallite size stays in low values until the beginning of anatase‐to‐rutile phase formation and the peak narrowing is originated from the reduction of the lattice microstrain practically (Figure 4(a)). Thus, the crystallite coalescence occurs as a consequence of the destroying-rebuilt oxygen-metallic cation bonds ...Understanding the anatase–rutile phase junction in …Understanding the anatase–rutile phase junction in charge separation and transfer in a TiO2 electrode for photoelectrochemical water splitting† Ailong Li,ab Zhiliang Wang,ab Heng Yin,ab Shengyang Wang,ab Pengli Yan,ab Baokun Huang,a Xiuli Wang,a Rengui Li,a Xu Zong,a Hongxian Han*ac and Can Li*ac New insight into junction-based designs for efficient charge …

Review of the anatase to rutile phase transformation

2017-8-28 · the anatase to rutile transformation, and the principles of controlling phase composition through the inhibition or promotion of the transformation of anatase to rutile. Titania polymorphs Titanium dioxide, the only naturally occurring oxide of titanium at atmospheric pressure, exhibits three poly-morphs: rutile, anatase, and brookite [1–7].Enhanced photocatalytic Fe reduction with H O TiO …2016-7-20 · 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 electron acceptor12. The present work shows that TiO

Structural Aspects of Anatase to Rutile Phase Transition ...

2016-11-17 · It was noticed that the crystallite size stays in low values until the beginning of anatase‐to‐rutile phase formation and the peak narrowing is originated from the reduction of the lattice microstrain practically (Figure 4(a)). Thus, the crystallite coalescence occurs as a consequence of the destroying-rebuilt oxygen-metallic cation bonds ...Production of Titanium Nitride by Carbothermic Reduction ...Reduction was completed in rutile sample before 1180°C whilst in anatase completed at 1230°C. TiN was the final product in both systems after heating to 1400°C.

Differences in the selective reduction mechanism of 4 ...

Ru/TiO2 catalysts exhibit excellent catalytic performance for selective reduction of 4-nitroacetophenone to 4-aminoacetophenone at normal temperature and atmospheric hydrogen pressure. Moreover, 99.9% selectivity to 4-aminoacetophenone can be obtained over 2.7 wt% Ru/TiO2(anatase) catalyst even in a relativeComparison of the reduction of metal oxide surfaces: TiO2 ...2005-5-20 · 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.

Photocatalytic Reduction of Uranyl Ions over Anatase and ...

2018-2-6 · Anatase and rutile nanostructured TiO 2 semiconductor catalysts were prepared by wet-chemical methods and used for the photoreduction of uranyl ions under UV radiation. It was found that there is an obvious difference between their catalytic performances: rutile TiO 2 nanorods give the highest activity per unit surface area, being over twice as active as P25 and …catalysts and rutile) nanoparticles as efficient ...2015-4-7 · anatase and rutile TiO2 phase (PDF no. 21-1272 and PDF no. 21-1276), respectively, indicating that pure anatase and rutile were also successfully prepared, and after being calcinated, the phase structures were maintained. Table S1 The calculated lattice parameters, unit cell volume, crystalline size and specific surface area

Iso-valent doping of reducible oxides: a comparison of ...

2021-9-29 · In rutile TiO 2 the predicted band gap is 1.94 eV; in anatase the gap is 2.73 eV, figure 2. Since the position of the O 2p VB is similar, 7.1–7.2 eV below vacuum, this means that the bottom of the CB in rutile is about 0.8 eV lower in energy that that of anatase (experimentally this energy difference is much smaller, about 0.2–0.4 eV).Phase Characterization of TiO Powder by XRD and TEM2010-3-4 · Kasetsart J. (Nat. Sci.) 42 : 357 - 361 (2008) Phase Characterization of TiO 2 Powder by XRD and TEM Kheamrutai Thamaphat 1*, Pichet Limsuwan1 and Boonlaer Ngotawornchai2 ABSTRACT In this study, the commercial TiO 2 nanopowder and micropowder of anatase phase and rutile phase have been characterized by x-ray diffraction (XRD) and transmission electron …

Band restructuring of ordered/disordered blue TiO2 for ...

Herein, we present a noble metal-free visible light photocatalyst, blue TiO 2, with type-II band-aligned ordered anatase/disordered rutile structures via phase-selective reduction with alkali metals. The changed band alignment in this heterostructure was identified by absorption and ultraviolet photoemission spectroscopy, which was further ...Review of the anatase to rutile phase transformation2017-8-28 · the anatase to rutile transformation, and the principles of controlling phase composition through the inhibition or promotion of the transformation of anatase to rutile. Titania polymorphs Titanium dioxide, the only naturally occurring oxide of titanium at atmospheric pressure, exhibits three poly-morphs: rutile, anatase, and brookite [1–7].

Role of point defects on the reactivity of ...

2013-7-30 · It should be mentioned that Ar + sputtering and annealing are commonly used for the reduction of rutile TiO 2 (ref. 1). We believe that a similar treatment is important to reduce the anatase TiO 2 ...Phase Characterization of TiO Powder by XRD and TEM2010-3-4 · Kasetsart J. (Nat. Sci.) 42 : 357 - 361 (2008) Phase Characterization of TiO 2 Powder by XRD and TEM Kheamrutai Thamaphat 1*, Pichet Limsuwan1 and Boonlaer Ngotawornchai2 ABSTRACT In this study, the commercial TiO 2 nanopowder and micropowder of anatase phase and rutile phase have been characterized by x-ray diffraction (XRD) and transmission electron …

Production of Titanium Nitride by Carbothermic Reduction ...

Reduction was completed in rutile sample before 1180°C whilst in anatase completed at 1230°C. TiN was the final product in both systems after heating to 1400°C. These results are discussed in light of recent work demonstrating the different reductions paths of rutile and anatase.Why is anatase a better photocatalyst than rutile? - Model ...2014-2-10 · The prototypical photocatalyst TiO2 exists in different polymorphs, the most common forms are the anatase- and rutile-crystal structures. Generally, anatase is …

Review of the anatase to rutile phase transformation ...

2010-12-8 · Titanium dioxide, TiO2, 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 phase transformation. The synthesis and properties of anatase and rutile are examined, followed by a …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 ...

Recent Advances in TiO2-Based Heterojunctions for ...

2021-4-15 · As a classic anatase-rutile phase heterojunction, the commercial Degussa P25 has been regarded as a benchmark for both photocatalytic oxidation and reduction reactions. As reported by Reñones et al., hierarchical TiO 2 nanofibres composed of anatase and rutile nanoparticles were synthesized by the calcination of electrospun TiO 2 fibers under ...Phase-selective Disorder Anatase/order Rutile Interface ...2019-9-10 · A phase-selective disorder anatase/order rutile interface system for visible-driven metal-free CO2 reduction using narrow-band structured TiO2, whose conduction band position is well-matched with reduction potential of CO2 to CH4 and CO. Visible light-driven photocatalytic CO2 reduction using TiO2 that can absorb all wavelengths of light has been sought for over …

Hydrogen Reduced Rutile Titanium Dioxide Photocatalyst ...

2016-11-23 · Highly efficient rutile photocatalyst is easily fabricated from P25 by H 2 reduction treatment at 700°C for 2 h [ 18 ]. The H 2 -reduced rutile TiO 2 outperforms anatase-rich TiO 2 because of the wider absorption range caused by its bandgap of rutile (3.0 eV) smaller than that of anatase (3.2 eV).Production of Titanium Nitride by Carbothermic Reduction ...Reduction was completed in rutile sample before 1180°C whilst in anatase completed at 1230°C. TiN was the final product in both systems after heating to 1400°C. These results are discussed in light of recent work demonstrating the different reductions paths of rutile and anatase.

Hydrogenation of TiO2 nanosheets and nanoparticles ...

When it comes to the reduction of nanoparticles, orientation-relative anisotropic disorder has been observed. It is found that the preferable disordered surface is along {001} for anatase, {100} for brookite and {001} for rutile, causing anisotropic stress deformation.Why is anatase a better photocatalyst than rutile? - Model ...2014-2-10 · The prototypical photocatalyst TiO2 exists in different polymorphs, the most common forms are the anatase- and rutile-crystal structures. Generally, anatase is …

Carbothermic Reduction of Anatase and Rutile., …

2005-1-31 · The reduction of rutile starts at about 830 °C, whereas reduction of anatase begins at 875 °C. The initial products are Ti 5 O 9 and Ti 4 O 7 with the latter being the last apparently stable phase prior to TiC formation. The TiC formed from anatase is stoichiometric whilst that from rutile is sub‐stoichiometric.Phase-selective Disorder Anatase/order Rutile Interface ...2019-9-10 · A phase-selective disorder anatase/order rutile interface system for visible-driven metal-free CO2 reduction using narrow-band structured TiO2, whose conduction band position is well-matched with reduction potential of CO2 to CH4 and CO. Visible light-driven photocatalytic CO2 reduction using TiO2 that can absorb all wavelengths of light has been sought for over …