Self-consistent tight binding molecular dynamics study of TiO2 nanoclusters in water

Erdin, Serkan; Lin, Yen-Hsiang; Halleý, J. W.; Zapol, Peter; Redfern, Paul C.; Curtiss, Larry A.

doi:10.1016/j.jelechem.2007.03.016

Cited by 11 publications

(17 citation statements)

References 27 publications

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“…The work presented here expands on a scheme involving stoichiometric clusters, which excludes unphysical low coordination for all cluster atoms and suppresses charge and dipole imbalances . Also, there have been several attempts to model electronic and geometrical properties of TiO 2 clusters in solution …”

Section: Introductionmentioning

confidence: 99%

Emerging polymorphism in nanostructured TiO₂: Quantum chemical comparison of anatase, rutile, and brookite clusters

Galynska

Persson

2013

Int. J. Quantum Chem.

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Density functional theory (DFT) and time-dependent DFT calculations have been performed on a set of 34 titanium dioxide clusters ((TiO2) n with n 125) to investigate structural and electronic properties of nanostructured TiO 2 (nano-TiO 2 ) materials. The investigated clusters include models of the three low-energy polymorphic forms of TiO 2 anatase, rutile, and brookite. A systematic comparison of clusters of increasing size show clear trends for emerging bulk properties in the investigated systems as the surface-to-bulk ratio changes from small clusters dominated by undercoordinated surface atoms to more realistic model nano-crystals with significant bulk components. Differences and similarities in terms of atomic coordination, structural stability, and electronic properties for the three different polymorphic forms of nano-TiO 2 are discussed. The calculations provide evidence for emerging polymorphism with increasing cluster sizes so that the different TiO 2 forms can be clearly distinguished based on structural characteristics associated with the local bonding environment of the constituent atoms.

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Section: Introductionmentioning

confidence: 99%

Emerging polymorphism in nanostructured TiO₂: Quantum chemical comparison of anatase, rutile, and brookite clusters

Galynska

Persson

2013

Int. J. Quantum Chem.

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“…It is important to explore a more detailed electronic description of the origin of the enhancement of the Raman activities of the organic molecules upon their adsorption on the TiO 2 nanoparticles. A dopamine-to-TiO 2 charge transfer model resulting in a decrease of the effective bandgap of TiO 2 was used to explain the enhancement of Raman activities observed in TiO 2 -dopamine complexes [2,34]. Assuming that the dopamine molecule is neutral, the positions of both the highest occupied (HOMO) and lowest unoccupied (LUMO) molecular orbitals of dopamine with respect to the bandgap in the nanoparticle, shown in Figure 8 are consistent with the proposed explanation of the enhancement.…”

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confidence: 99%

Quantum confinement effects on the surface enhanced Raman spectra of hybrid systems molecule‐TiO₂ nanoparticles

Tarakeshwar

Finkelstein-Shapiro

Rajh

et al. 2010

Int J of Quantum Chemistry

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ABSTRACT:The role of quantum confinement, size, and solvent effects on the surface enhanced Raman spectra of biologically important molecules absorbed on semiconducting titanium dioxide (TiO 2 ) nanoparticles is investigated using density functional calculations. The results obtained for both the gas phase and solvated systems indicate significant changes in the electronic structure and the Raman spectra of molecules like formic acid and dopamine, when they are adsorbed on small TiO 2 nanoparticles. A number of distinctive features that are determined by the formation of a charge-transfer complex at the nanoparticle-molecule interface can be noted in the Raman spectra. Both the spectra and the electronic properties are strongly size dependent and are also sensitive to the presence of the solvent and the nature of adsorbate interaction. Although these calculations reinforce recent experimental findings on the role of quantum confinement, they also pose new questions about the extension of collective effects and the effect of pH and other environmental variables.

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“…We have already used the water model described here for one such study. 10 Another self consistent tight binding model for water was quite recently reported by Paxton and Kohanoff. 11 The basic physics is very similar but the method for taking account of the polarizability of the oxygen entities in the model differs in some details from the method used here as described in more detail in Appendix A of this paper and in Ref.…”

Section: Introductionmentioning

confidence: 91%

“…An advantage of the model reported here is that it has been constructed to be completely compatible with our previous SCTB models of oxides, so that it can be used, as already reported in Ref. 10, to study oxide-water interfaces.…”

Section: Introductionmentioning

confidence: 95%

“…For the tight binding fits, we started with hydrogen-oxygen parameters given for a somewhat similar water model (which, however, was not self consistent) due to Sankey and co-workers. 16 However, for oxygen-oxygen parameters we used values obtained in our most recent SCTB model of titanium dioxide 10 so that the same model parameters for oxygen could be used later to simulate the water-oxide interface. The final parameter set is presented in Appendix B.…”

Section: Determination Of Sctb Parameters For Watermentioning

confidence: 99%

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Self consistent tight binding model for dissociable water

Lin¹,

Wynveen

Halleý

et al. 2012

The Journal of Chemical Physics

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We report results of development of a self consistent tight binding model for water. The model explicitly describes the electrons of the liquid self consistently, allows dissociation of the water and permits fast direct dynamics molecular dynamics calculations of the fluid properties. It is parameterized by fitting to first principles calculations on water monomers, dimers, and trimers. We report calculated radial distribution functions of the bulk liquid, a phase diagram and structure of solvated protons within the model as well as ac conductivity of a system of 96 water molecules of which one is dissociated. Structural properties and the phase diagram are in good agreement with experiment and first principles calculations. The estimated DC conductivity of a computational sample containing a dissociated water molecule was an order of magnitude larger than that reported from experiment though the calculated ratio of proton to hydroxyl contributions to the conductivity is very close to the experimental value. The conductivity results suggest a Grotthuss-like mechanism for the proton component of the conductivity.

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Self-consistent tight binding molecular dynamics study of TiO2 nanoclusters in water

Cited by 11 publications

References 27 publications

Emerging polymorphism in nanostructured TiO₂: Quantum chemical comparison of anatase, rutile, and brookite clusters

Emerging polymorphism in nanostructured TiO₂: Quantum chemical comparison of anatase, rutile, and brookite clusters

Quantum confinement effects on the surface enhanced Raman spectra of hybrid systems molecule‐TiO₂ nanoparticles

Self consistent tight binding model for dissociable water

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Self-consistent tight binding molecular dynamics study of TiO2 nanoclusters in water

Cited by 11 publications

References 27 publications

Emerging polymorphism in nanostructured TiO2: Quantum chemical comparison of anatase, rutile, and brookite clusters

Emerging polymorphism in nanostructured TiO2: Quantum chemical comparison of anatase, rutile, and brookite clusters

Quantum confinement effects on the surface enhanced Raman spectra of hybrid systems molecule‐TiO2 nanoparticles

Self consistent tight binding model for dissociable water

Contact Info

Product

Resources

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Emerging polymorphism in nanostructured TiO₂: Quantum chemical comparison of anatase, rutile, and brookite clusters

Emerging polymorphism in nanostructured TiO₂: Quantum chemical comparison of anatase, rutile, and brookite clusters

Quantum confinement effects on the surface enhanced Raman spectra of hybrid systems molecule‐TiO₂ nanoparticles