Erratum: Structure and energetics of stoichiometric<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">TiO</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>anatase surfaces [Phys. Rev. B<b>63</b>, 155409 (2001)]

Lazzeri, Michele; Vittadini, Andrea; Selloni, Annabella

doi:10.1103/physrevb.65.119901

Cited by 631 publications

(910 citation statements)

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“…The preferred orientation is determined by a configuration of minimum total energy, which results from competition between the planes with minimum deformation energy, and the planes with minimum surface energy. , respectively [29]. In general, based on the Wulff construction, according to which surface energy minimization drives the optimal composition of the crystal surface, the (101) plane and the (001) plane were shown to be the most thermodynamically stable planes of anatase crystallites [30,31], which is also in agreement with the natural minerals.…”

Section: Resultssupporting

confidence: 58%

Preparation and characterization of dye-sensitized TiO2 nanorod solar cells

Chen

et al. 2015

Thin Solid Films

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TiO 2 nanorods were prepared by DC reactive magnetron sputtering technique and applied to dye-sensitized solar cells (DSSCs). The length of the TiO 2 nanorods was varied from 1 μm to 6 μm. The scanning electron microscopy images show that the nanorods are perpendicular to the substrate. Both the X-ray diffraction patterns and Raman scattering results show that the nanorods have an anatase phase; no other phase has been observed. (101) and the (220) diffraction peaks have been observed for the TiO 2 nanorods. The (101) diffraction peak intensity remained constant despite the increase of nanorod length, while the intensity of the (220) diffraction peak increased almost linearly with the nanorod length. These nanorods were used as the working electrodes in DSSCs and the effect of the nanorod length on the conversion efficiency has been studied. An optimum photoelectric conversion efficiency of 4.8% has been achieved for 4 μm length nanorods.

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Section: Resultssupporting

confidence: 58%

Preparation and characterization of dye-sensitized TiO2 nanorod solar cells

Chen

et al. 2015

Thin Solid Films

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“…The average surface free energy of (0 0 1) facets is 0.90 J/m 2 , which is higher than those of (1 0 0) (0.53 J/m 2 ) and (1 0 1) facets (0.44 J/m 2 ) [31]. The majority of exposed facets of anatase TiO 2 are normally (1 0 1) due to it having the lowest surface energy under common conditions.…”

Section: Introductionmentioning

confidence: 91%

Photocatalytic oxidation of gaseous ammonia over fluorinated TiO2 with exposed (001) facets

et al. 2014

Applied Catalysis B: Environmental

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a b s t r a c tA surface-fluorinated TiO 2 (F-TiO 2 ) catalyst was synthesized by a hydrothermal method using hydrofluoric acid (HF) solution as a capping agent, and defluorinated TiO 2 (D-TiO 2 ) was next obtained by washing the F-TiO 2 with NaOH solution. The as-prepared catalysts were tested for the photocatalytic oxidation (PCO) of gaseous NH 3 under UV light. The F-TiO 2 catalyst exhibited remarkable activity for NH 3 removal, about twice as high as that of the commercial catalyst P25. In contrast, D-TiO 2 showed an obvious decrease in PCO activity. The catalysts were characterized by X-ray diffractometry (XRD), Brunauer-Emmett-Teller (BET) adsorption analysis, High-resolution Transmission electron microscopy (HR-TEM), and X-ray photoelectron spectroscopy (XPS). The results showed that the surface fluorination process formed the surface Ti-F group and also increased the percentage of reactive (0 0 1) facets to about 50%; the surface defluorination removed the fluorine (F) element from the F-TiO 2 surface but showed no influence on the percentage of reactive (0 0 1) facets. By comparing the specific activities of the catalysts, we found that both the active (0 0 1) facets and the surface Ti-F group contributed to the improvement of the PCO activity, while the surface Ti-F group plays the dominant role. The Ti-F group could retard the recombination of photogenerated electrons and holes, which is possibly the major reason for the excellent activity of the F-TiO 2 catalyst.

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“…These results from DFT may aid in the design of improved catalysts for mercury oxidation while simultaneously maintaining optimal performance for NO x reduction. The TiO 2 (001) surface has been studied previously, 16,25,30,72 and is shown in Figure 9. It is composed of five-coordinated Ti atoms bonded to two O atoms along the (001) direction and to three O atoms in the (010) direction.…”

Section: ■ Conclusionmentioning

confidence: 99%

DFT Study of Hg Oxidation across Vanadia-Titania SCR Catalyst under Flue Gas Conditions

2013

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The density functional theory was used to analyze the thermodynamic stability and reactivity of the vanadia-titania catalyst below monolayer regime with the purpose of having a good representation of a commercial SCR catalyst (V 2 O 5 (<2 wt %)−TiO 2 ). The objective of this paper is to understand the reactivity of this catalyst in Hg oxidation. The SCR catalyst is modeled as a tetrahedrally coordinated divanadate unit supported on a 3-layer TiO 2 (001) slab to represent a catalyst with low vanadia loadings. Under flue gas conditions, the interaction of water with this surface has been studied as a function of pressure and temperature using ab initio thermodynamic calculations, showing that water coverage is temperature-dependent. Adsorbed water acts as a Lewis base, donating electrons to the TiO 2 (001) surface support, which increases the negative charge and reactivity of the oxygen atoms of the vanadia dimer. The reactivity of the vanadia dimer toward Hg oxidation is analyzed through the adsorption energies of Hg, HgCl, HCl, and H 2 O. Surfaces with high water coverage showed higher reactivity toward HgCl, which has the highest adsorption energy, followed by HCl. The adsorption energies of Hg suggest a negligible interaction with the vanadia dimer. Lateral interactions between neighboring adsorbed flue gas components on the vanadia dimer were studied, suggesting that having H 2 O or HgCl adsorbed on a neighboring oxygen atom increases the adsorption energies of Hg and HCl respectively. Temperature, pressure, and entropic effects were taken into account to study the reactivity of these surface interactions under flue gas conditions. Based on these results, it is proposed that the oxidation of Hg to HgCl 2 follows a Langmuir−Hinshelwood mechanism, represented as a cycle where HgCl and HCl interact without poisoning the surface. The proposed steps during the formation of HgCl 2 are the adsorption and dissociation of HCl, adsorption of HgCl, formation of HgCl 2 , and its desorption from the surface. ■ INTRODUCTIONThe U.S. Environmental Protection Agency (EPA) proposed the Mercury and Air Toxics Standards (MATS) in December 2011, which require U.S. natural gas and coal-fired power plants to install air pollution control devices to prevent 91% of the Hg present in flue gas from being released.1 Rising atmospheric levels of gaseous Hg have caused public concern because Hg has been shown to have negative neurological effects, affecting memory, attention, language, and visual skills.2 In the U.S., 40% of the total coal-fired generating capacity is generated in power plants equipped with selective catalytic reduction (SCR) units . Oxidized Hg is highly soluble in aqueous solutions, making its removal by conventional wet flue gas desulfurization processes possible. 5−7A widely employed material in commercial SCR units is titaniasupported vanadium and tungsten oxides, that is, V 2 O 5 −WO 3 / TiO 2 . 8,9 The active vanadia phase, V 2 O 5 , is responsible for NO x reduction 10 and can also catalyze Hg 0 oxidatio...

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Erratum: Structure and energetics of stoichiometricTiO2anatase surfaces [Phys. Rev. B63, 155409 (2001)]

Cited by 631 publications

References 0 publications

Preparation and characterization of dye-sensitized TiO2 nanorod solar cells

Preparation and characterization of dye-sensitized TiO2 nanorod solar cells

Photocatalytic oxidation of gaseous ammonia over fluorinated TiO2 with exposed (001) facets

DFT Study of Hg Oxidation across Vanadia-Titania SCR Catalyst under Flue Gas Conditions

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