Dynamics of charge at water-to-semiconductor interface: Case study of wet [0 0 1] anatase TiO2 nanowire

Huang, Shuping; Balasanthiran, Choumini; Tretiak, Sergei; Hoefelmeyer, James D.; Kilina, Svetlana; Kilin, Dmitri S.

doi:10.1016/j.chemphys.2016.08.002

Cited by 5 publications

(3 citation statements)

References 85 publications

(86 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As expected, the NAC between adjacent states (e.g., the subdiagonals) is larger than the couplings between energetically distant electronic states. This trend is consistent with the notion that the magnitude of NAC between two states is inversely proportional to the energy gap between them. , Comparing the average NAC between the HOMO and LUMO states in SiR- and GeR-based heterostructures, we observe larger magnitudes in the latter. The average NAC between HOMO and LUMO states is 0.04 meV in SiH/a-TiO 2 and 0.26 meV in SiH/r-TiO 2 , whereas it increases to 0.54 meV in GeH/a-TiO 2 and 3.00 meV in GeH/r-TiO 2 .…”

Section: Resultssupporting

confidence: 91%

Excited-State Dynamics in Two-Dimensional Heterostructures: SiR/TiO₂ and GeR/TiO₂ (R = H, Me) as Promising Photocatalysts

Nijamudheen

Akimov

2017

J. Phys. Chem. C

View full text Add to dashboard Cite

The electronic structure and excited-state dynamics of heterojunctions composed of 2D silicane and germanane-based materials (SiR, GeR; R = H, Me) and anatase or rutile isomorphs of TiO2 are investigated. Our calculations reveal a high tunability of the band gaps of these heterostructures: 2.28 eV in SiH/a-TiO2 to 0.16 eV in GeMe/r-TiO2. Nonadiabatic molecular dynamic (NA-MD) simulations suggest that electron–hole recombination in SiH/a-TiO2, SiH/r-TiO2, and GeH/a-TiO2 occurs within 46.0, 3.6, and 1.2 ns, respectively, which is notably slower than in other analogous materials. The methylation of Si or Ge monolayers and the use of rutile polymorphs increase the nonadiabatic coupling and accelerate the recombination. A simple accelerated NA-MD method is devised in this work to evaluate the time scales for extremely slow dynamics of excited states. On the contrary to the electron–hole recombination, “hot” electrons are found to thermalize within a picosecond time scale, whereas some hot holes thermalize notably slower, on the order of 20.5 ps in SiH/a-TiO2 and 65.3 ps in GeH/a-TiO2. High tunability of the band gaps, suitable electron and hole localization, and long recombination time scales suggest that SiH/a-TiO2, SiH/r-TiO2, and GeH/a-TiO2 heterostructures may be promising candidates for photocatalytic applications.

show abstract

Section: Resultssupporting

confidence: 91%

Excited-State Dynamics in Two-Dimensional Heterostructures: SiR/TiO₂ and GeR/TiO₂ (R = H, Me) as Promising Photocatalysts

Nijamudheen

Akimov

2017

J. Phys. Chem. C

View full text Add to dashboard Cite

show abstract

“…The electronic structure of bulk anatase TiO 2 has been described elsewhere. , It is an indirect band gap semiconductor (E g ∼ 3.2 eV) with intense absorption in the UV region due to O 2p → Ti 3d ligand to metal charge transfer (LMCT). However, TiO 2 nanostructures with dimension <5 nm undergo significant changes in electronic structure due to quantum confinement and transition to a direct band gap semiconductor. − In anatase TiO 2 nanosheets, quantum confinement leads to a slight negative shift of the conduction band edge potential of ∼0.08 V, and a positive shift of the valence band edge by ∼0.5 V yields a bandgap of ∼3.8 eV. , The thickness of TiO 2 NR and TiO 2 nanosheets are very similar, and both materials give rise to strongly blue-shifted UV–visible spectra …”

Section: Resultsmentioning

confidence: 99%

“…91,92 The thickness of TiO 2 NR and TiO 2 nanosheets are very similar, and both materials give rise to strongly blue-shifted UV−visible spectra. 93 Addition of transition metal ions to the surface of TiO 2 NR leads to changes in the UV−visible spectrum. The UV−visible spectra of M-TiO 2 samples were reported previously.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Quantitative Attachment of Bimetal Combinations of Transition-Metal Ions to the Surface of TiO₂ Nanorods

et al. 2018

Self Cite

View full text Add to dashboard Cite

We report the sequential, quantitative loading of transition-metal ions (Cr, Mn, Fe, Co, Ni, and Cu) onto the surface of rod-shaped anatase TiO nanocrystals in bimetallic combinations ( C = 15) to form M,M'-TiO nanocrystals. The materials were characterized with transmission electron microscopy (TEM), powder X-ray diffraction (XRD), elemental analysis, X-ray photoelectron spectroscopy (XPS), and UV-visible spectroscopy. TEM and XRD data indicate that the sequential adsorption of metal ions occurs with the retention of the phase and morphology of the nanocrystal. Atomistic models of the M,M'-TiO nanocrystals were optimized with density functional theory calculations. Calculated UV-visible absorption spectra and partial charge density maps of the donor and acceptor states for the electronic transitions indicate the importance of metal-to-metal charge transfer (MMCT) processes.

show abstract

Quantum Dynamics Effects in Photocatalysis

Nijamudheen

Akimov

2018

Visible Light‐Active Photocatalysis

View full text Add to dashboard Cite

Dynamics of charge at water-to-semiconductor interface: Case study of wet [0 0 1] anatase TiO2 nanowire

Cited by 5 publications

References 85 publications

Excited-State Dynamics in Two-Dimensional Heterostructures: SiR/TiO₂ and GeR/TiO₂ (R = H, Me) as Promising Photocatalysts

Excited-State Dynamics in Two-Dimensional Heterostructures: SiR/TiO₂ and GeR/TiO₂ (R = H, Me) as Promising Photocatalysts

Quantitative Attachment of Bimetal Combinations of Transition-Metal Ions to the Surface of TiO₂ Nanorods

Quantum Dynamics Effects in Photocatalysis

Contact Info

Product

Resources

About

Dynamics of charge at water-to-semiconductor interface: Case study of wet [0 0 1] anatase TiO2 nanowire

Cited by 5 publications

References 85 publications

Excited-State Dynamics in Two-Dimensional Heterostructures: SiR/TiO2 and GeR/TiO2 (R = H, Me) as Promising Photocatalysts

Excited-State Dynamics in Two-Dimensional Heterostructures: SiR/TiO2 and GeR/TiO2 (R = H, Me) as Promising Photocatalysts

Quantitative Attachment of Bimetal Combinations of Transition-Metal Ions to the Surface of TiO2 Nanorods

Quantum Dynamics Effects in Photocatalysis

Contact Info

Product

Resources

About

Excited-State Dynamics in Two-Dimensional Heterostructures: SiR/TiO₂ and GeR/TiO₂ (R = H, Me) as Promising Photocatalysts

Excited-State Dynamics in Two-Dimensional Heterostructures: SiR/TiO₂ and GeR/TiO₂ (R = H, Me) as Promising Photocatalysts

Quantitative Attachment of Bimetal Combinations of Transition-Metal Ions to the Surface of TiO₂ Nanorods