Impurity levels of iron-group ions in TiO2(II)

Mizushima, Koichi; Tanaka, Mitsuaki; Asai, Akio; Iida, Shūichi; Goodenough, John B

doi:10.1016/0022-3697(79)90148-3

Cited by 182 publications

(83 citation statements)

References 19 publications

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“…43 Mizushima et al, from optical absorption data and photocurrent measurements, calculated the impurity levels of some iron-group ions in rutile. 64 The presence of such levels was invoked by Grätzel and Howe 44 to explain the role of Fe, V, and Mo on the photoreactivity of TiO 2 colloids.…”

Section: Discussionmentioning

confidence: 98%

Preparation of Polycrystalline TiO₂ Photocatalysts Impregnated with Various Transition Metal Ions: Characterization and Photocatalytic Activity for the Degradation of 4-Nitrophenol

et al. 2001

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A set of polycrystalline TiO 2 photocatalysts loaded with various ions of transition metals (Co, Cr, Cu, Fe, Mo, V, and W) were prepared by using the wet impregnation method. The samples were characterized by using some bulk and surface techniques, namely X-ray diffraction, BET specific surface area determination, scanning electron microscopy, point of zero charge determination, and femtosecond pump-probe diffuse reflectance spectroscopy (PP-DRS). The samples were employed as catalysts for 4-nitrophenol photodegradation in aqueous suspension, used as a probe reaction. The characterization results have confirmed the difficulty to find a straightforward correlation between photoactivity and single specific properties of the powders. Diffuse reflectance measurements showed a slight shift in the band gap transition to longer wavelengths and an extension of the absorption in the visible region for almost all the doped samples. SEM observation and EDX measurements indicated a similar morphology for all the particles, and a not homogeneous distribution of the metal species onto the surface of catalyst particles. The impregnated samples revealed recombination rates always higher than that of bare TiO 2 . The photoactivity of TiO 2 was reduced by the presence of transition metal ions with the exception of W, which instead played a beneficial role. The results of femtosecond pumpprobe diffuse reflectance spectroscopy appear quite in accord with the observed photocatalytic activity only for the lowest values of electron-hole recombination rate of the samples.

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Section: Discussionmentioning

confidence: 98%

Preparation of Polycrystalline TiO₂ Photocatalysts Impregnated with Various Transition Metal Ions: Characterization and Photocatalytic Activity for the Degradation of 4-Nitrophenol

et al. 2001

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“…Recent reports from Klosek et al also indicate that V 4+ -doped TiO 2 is quite active under visible-light irradiation [17]. Visible absorption in these catalysts is indicative of the excitation of a 3d electron from a V 4+ center into the TiO 2 conduction band [18]. To the best of our knowledge, there has been no related theoretical work which attempts to rationalize and explain the relationship between electronic structure and photocatalytic activity underlined by these experimental observations.…”

Section: Introductionmentioning

confidence: 89%

First‐principles calculation of electronic structure of V‐doped anatase TiO₂

Long

English

2010

ChemPhysChem

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The energetic and electronic structures of V‐doped anatase TiO2 have been investigated systematically by the GGA+U approach, including replacement of Ti by V in the absence and presence of oxygen vacancies and the presence of an interstitial site. It was found that V should exist as a V4+ ion in the replacement of Ti in the anatase lattice, the electron transitions of which to the conduction band from V 3d states are responsible for the experimentally observed visible light absorption. The influence of V dopant concentration on the electronic and magnetic properties is also discussed, such as the influence of the U value in systems containing oxygen vacancies and spin flip phenomena for interstitial V‐doping.

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“…4) Experimentally, the formation of localized TM dopant states have been studied by electron spin resonance in TiO 2 crystals where the Fermi level position was adjusted by Li doping. 5) In this paper, we report on a systematic photoemission spectroscopy study of TM-doped (TM = V, Cr, Mn, Fe, Co, and Ni) TiO 2 films grown on Nb-doped TiO 2 single crystal substrates for various film thicknesses and including a non-doped TiO 2 /Nb:TiO 2 sample as a reference. In this study, there are two methodological key points: The first is the use of the combinatorial laser molecular beam epitaxy (LMBE) method, 6) which enabled us to grow thickness gradient samples for an efficient trace of thickness-dependent electronic properties.…”

Section: Introductionmentioning

confidence: 99%

Chemical trend of Fermi-level shift in transition metal-doped TiO2 films

Matsumoto¹,

Katayama²,

Abe³

et al. 2010

J. Ceram. Soc. Japan

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The effect of doping a wide range of transition metals (TMs) including V, Cr, Mn, Fe, Co, and Ni into rutile TiO 2 films grown on Nb-doped TiO 2 (110) single-crystal substrates was investigated by photoemission spectroscopy and X-ray absorption spectroscopy. For all TM-doped TiO 2 films, the Ti 2p and O 1s core levels were similarly shifted to lower binding energies with increasing film thickness and the shifts were similarly saturated at a film thickness of about 15 nm. These peak shifts could be interpreted in terms of the Fermi level shift, indicating that dopants trap excess electrons from the Ti 3d band like acceptors. The present systematic data revealed that the magnitude of the saturated Fermi level shift correlates well with the effective charge transfer energy.

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Impurity levels of iron-group ions in TiO2(II)

Cited by 182 publications

References 19 publications

Preparation of Polycrystalline TiO₂ Photocatalysts Impregnated with Various Transition Metal Ions: Characterization and Photocatalytic Activity for the Degradation of 4-Nitrophenol

Preparation of Polycrystalline TiO₂ Photocatalysts Impregnated with Various Transition Metal Ions: Characterization and Photocatalytic Activity for the Degradation of 4-Nitrophenol

First‐principles calculation of electronic structure of V‐doped anatase TiO₂

Chemical trend of Fermi-level shift in transition metal-doped TiO2 films

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Impurity levels of iron-group ions in TiO2(II)

Cited by 182 publications

References 19 publications

Preparation of Polycrystalline TiO2 Photocatalysts Impregnated with Various Transition Metal Ions: Characterization and Photocatalytic Activity for the Degradation of 4-Nitrophenol

Preparation of Polycrystalline TiO2 Photocatalysts Impregnated with Various Transition Metal Ions: Characterization and Photocatalytic Activity for the Degradation of 4-Nitrophenol

First‐principles calculation of electronic structure of V‐doped anatase TiO2

Chemical trend of Fermi-level shift in transition metal-doped TiO2 films

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Product

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Preparation of Polycrystalline TiO₂ Photocatalysts Impregnated with Various Transition Metal Ions: Characterization and Photocatalytic Activity for the Degradation of 4-Nitrophenol

Preparation of Polycrystalline TiO₂ Photocatalysts Impregnated with Various Transition Metal Ions: Characterization and Photocatalytic Activity for the Degradation of 4-Nitrophenol

First‐principles calculation of electronic structure of V‐doped anatase TiO₂