Electronic Structure of F-Doped Bulk Rutile, Anatase, and Brookite Polymorphs of TiO<sub>2</sub>

Tosoni, Sergio; Lamiel-García, Oriol; Hevia, Daniel Fernández; Doña, J. M.; Illas, Francesc

doi:10.1021/jp301332a

Cited by 69 publications

(74 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As shown in Fig. 2, the band gaps of the surfaces with absorbates become slightly bigger than that of TiO 2 110, in agreement with previous results [30]. Thus, the degradation and mineralization of organic compounds on F-TiO 2 should still rely on the irradiation of UV light, in agreement with most photocatalytic activity measurements.…”

Section: Dft Resultssupporting

confidence: 90%

Photocatalytic Behavior of Fluorinated Rutile TiO₂(110) Surface: Understanding from the Band Model

et al. 2017

View full text Add to dashboard Cite

Surface fluorination of TiO 2 (F-TiO 2 ) has complicate photocatalytic behavior in degradation of organic compounds. This work attempts to establish an elegant scenario based on the band model to understand this behavior. Density functional theory (DFT) calculations show that fluorination of the rutile TiO 2 (110) surface (F-TiO 2 110) results in the falling of band edges. The falling of valence band edge (VBE) facilitates production of free ·OH radicals, whereas the falling of conduction band edge (CBE) lowers the reducing power of photo-electrons and inhibits reductive reactions mediated by them. As a result, the photo-electrons are built up in the conduction band which depresses photo-holes in the valence band to produce ·OH radicals due to the requirement of electrical neutrality and thus leads to a low degradation rate of organic compounds. Even though, our model suggests a route to improve the degradation efficiency, by introducing a scavenger of photo-electrons to promote formation of ·OH radicals.

show abstract

Section: Dft Resultssupporting

confidence: 90%

Photocatalytic Behavior of Fluorinated Rutile TiO₂(110) Surface: Understanding from the Band Model

et al. 2017

View full text Add to dashboard Cite

show abstract

“…46,47,48 In this work, we set the U parameter to 4 eV for Zr and 3 eV for Ti atoms. With these parameters, a good qualitative description of the electronic and geometric structures is given, 49,50,51,52 giving 4.0 eV and 2.4 eV for the ZrO 2 and TiO 2 band gaps, respectively.…”

Section: Methodsmentioning

confidence: 99%

Gold and Silver Clusters on TiO₂ and ZrO₂ (101) Surfaces: Role of Dispersion Forces

2015

View full text Add to dashboard Cite

The adsorption of Ag and Au atoms and Ag 4 and Au 4 clusters on the stoichiometric TiO 2 (anatase) and ZrO 2 (tetragonal) (101) surfaces has been investigated using DFT+U calculations with and without the inclusion of van der Waals (VdW) forces. We have considered the role of VdW interactions on the physical properties of the adsorbed species using three different approaches: two variants of the pair-wise force field method proposed by Grimme (DFT+D2 and DFT+D2'), and the vdW-DF method where the vdW contribution is expressed directly as a function of the electron density. The results show that already at the level of metal atoms and small clusters the inclusion of vdW interactions can change the order of stability of various isomers and, more important, can result in major corrections to the adsorption energies. These, in turn, can affect other properties as for instance the structure and chemical reactivity of supported metal particles on oxides or their diffusion properties.

show abstract

“…For example, the relaxed lattice parameters are in reasonable agreement with the experiment (errors on the cell volume < 5-6%). 41,42,43 There are several polymorphs of TiO 2 -anatase, rutile, brookite and some high pressure phases. Although rutile is the thermodynamically stable bulk phase at all temperatures, 44,45,46 5 anatase is the most common phase in catalytic applications.…”

Section: Methodsmentioning

confidence: 99%

Hydrogen Adsorption, Dissociation, and Spillover on Ru₁₀ Clusters Supported on Anatase TiO₂ and Tetragonal ZrO₂ (101) Surfaces

2015

Self Cite

View full text Add to dashboard Cite

The scope of this work is to study at atomistic level the mechanism of hydrogen spillover promoted by metal particles on oxide surfaces. By means of Density Functional Theory calculations with Hubbard correction (DFT+U) we have analyzed the adsorption and dissociation of molecular hydrogen on anatase titania, a-TiO 2 (101), and tetragonal zirconia, t-ZrO 2 (101), surfaces in the presence of a supported Ru 10 nanocluster. The role of the supported metal particle is essential as it favours the spontaneous dissociation of H 2 , a process which does not occur on the bare oxide surface. At low hydrogen coverage, the H atoms prefer to stay on the Ru 10 particle, charge accumulates on the metal cluster, and reduction of the oxide does not take place. On a hydroxylated surface, the presence of a Ru nanoparticle is expected to promote the reverse effect, i.e. hydrogen reverse spillover from the oxide to the supported metal. It is only at high hydrogen coverage, resulting in the adsorption of several H 2 molecules on the metal cluster, that it becomes thermodynamically favourable to have hydrogen transfer from the metal to the O sites of the oxide surface. In both TiO 2 and ZrO 2 surfaces the migration of an H atom from the Ru cluster to the surface is accompanied by an electron transfer to the empty states of the support with reduction of the oxide surface.

show abstract

Electronic Structure of F-Doped Bulk Rutile, Anatase, and Brookite Polymorphs of TiO₂

Cited by 69 publications

References 69 publications

Photocatalytic Behavior of Fluorinated Rutile TiO₂(110) Surface: Understanding from the Band Model

Photocatalytic Behavior of Fluorinated Rutile TiO₂(110) Surface: Understanding from the Band Model

Gold and Silver Clusters on TiO₂ and ZrO₂ (101) Surfaces: Role of Dispersion Forces

Hydrogen Adsorption, Dissociation, and Spillover on Ru₁₀ Clusters Supported on Anatase TiO₂ and Tetragonal ZrO₂ (101) Surfaces

Contact Info

Product

Resources

About

Electronic Structure of F-Doped Bulk Rutile, Anatase, and Brookite Polymorphs of TiO2

Cited by 69 publications

References 69 publications

Photocatalytic Behavior of Fluorinated Rutile TiO2(110) Surface: Understanding from the Band Model

Photocatalytic Behavior of Fluorinated Rutile TiO2(110) Surface: Understanding from the Band Model

Gold and Silver Clusters on TiO2 and ZrO2 (101) Surfaces: Role of Dispersion Forces

Hydrogen Adsorption, Dissociation, and Spillover on Ru10 Clusters Supported on Anatase TiO2 and Tetragonal ZrO2 (101) Surfaces

Contact Info

Product

Resources

About

Electronic Structure of F-Doped Bulk Rutile, Anatase, and Brookite Polymorphs of TiO₂

Photocatalytic Behavior of Fluorinated Rutile TiO₂(110) Surface: Understanding from the Band Model

Photocatalytic Behavior of Fluorinated Rutile TiO₂(110) Surface: Understanding from the Band Model

Gold and Silver Clusters on TiO₂ and ZrO₂ (101) Surfaces: Role of Dispersion Forces

Hydrogen Adsorption, Dissociation, and Spillover on Ru₁₀ Clusters Supported on Anatase TiO₂ and Tetragonal ZrO₂ (101) Surfaces