.png){kind=icon}
.png){kind=icon}
Return
Understanding the Thermodynamics of Water on Anatase TiO2(101)-Faceted Nanocrystals
.png){kind=icon}
PRE
AI
C
B
L
M
G
M
J
S
王
DOI：10.1021/acs.jpcc.5c08625.png)
.png){kind=icon}
Original request for help.png){kind=icon}
Share.png){kind=icon}
Save
Abstract
En 中文
Hydrated TiO2 nanocrystals play a central role in photocatalysis and biomass conversion; however, the molecular-level structure of water on anatase (101) remains actively debated. Here, we synthesize anatase nanocrystals that expose >90% of the (101) facet with minimal surface contamination, and we combine in situ diffuse reflectance infrared spectroscopy (DRIFTS) with first-principles calculations to establish a consistent thermodynamic and vibrational picture of adsorbed water up to 1.0 monolayer. Density functional theory is used to compute the adsorption energetics, harmonic and anharmonic vibrational spectra, and the free-energy phase diagram. The calculations show that the stoichiometric (101) surface favors a full monolayer of molecularly adsorbed H2O at temperatures (298–355 K), with dissociated hydroxyls becoming favorable only at elevated temperatures and pressures. Projection analyses of the computed normal modes enable rigorous assignment of the ν(OH) region and clarify long-standing ambiguities in peak interpretation. Comparison with DRIFTS spectra reveals that a commonly reported feature near 3640 cm–1 corresponds to a red-shifted terminal OH group rather than to a water symmetric stretch. The integrated thermodynamic and spectroscopic analysis provides a refined framework for identifying molecular and dissociated water on anatase TiO2(101) and establishes reference points for interpreting water-mediated surface chemistry in oxide-catalyzed transformations.
Keywords:
Adsorption
Hydroxyls
Minerals
Oxides
Thermodynamic properties
Journal
T
IF:
3.2
Papers:
1.2K
Citations:
4