@article{876ac726b06744cb9d738517b3e16a69,
title = "Free energy of proton transfer at the water-TiO2 interface from: ab initio deep potential molecular dynamics",
abstract = "TiO2 is a widely used photocatalyst in science and technology and its interface with water is important in fields ranging from geochemistry to biomedicine. Yet, it is still unclear whether water adsorbs in molecular or dissociated form on TiO2 even for the case of well-defined crystalline surfaces. To address this issue, we simulated the TiO2-water interface using molecular dynamics with an ab initio-based deep neural network potential. Our simulations show a dynamical equilibrium of molecular and dissociative adsorption of water on TiO2. Water dissociates through a solvent-assisted concerted proton transfer to form a pair of short-lived hydroxyl groups on the TiO2 surface. Molecular adsorption of water is ΔF = 8.0 ± 0.9 kJ mol-1 lower in free energy than the dissociative adsorption, giving rise to a 5.6 ± 0.5% equilibrium water dissociation fraction at room temperature. Due to the relevance of surface hydroxyl groups to the surface chemistry of TiO2, our model might be key to understanding phenomena ranging from surface functionalization to photocatalytic mechanisms.",
author = "Andrade, {Marcos F.Calegari} and Ko, {Hsin Yu} and Linfeng Zhang and Roberto Car and Annabella Selloni",
note = "Funding Information: This work was conducted within the Computational Chemical Center: Chemistry in Solution and at Interfaces funded by the DoE under Award DE-SC0019394. A. S. acknowledge the support of DoE-BES, Division of Chemical Sciences, Geosciences and Biosciences under Award DE-SC0007347. M. C. A. acknowledges partial nancial support from the CNPq-Brazil. We used resources of the National Energy Research Scientic Computing Center (DoE Contract No. DE-AC02-05cH11231). We also acknowledge use of the TIGRESS High Performance Computer Center at Princeton University. Funding Information: This work was conducted within the Computational Chemical Center: Chemistry in Solution and at Interfaces funded by the DoE under Award DE-SC0019394. A. S. acknowledge the support of DoE-BES, Division of Chemical Sciences, Geosciences and Biosciences under Award DE-SC0007347. M. C. A. acknowledges partial financial support from the CNPq-Brazil. We used resources of the National Energy Research Scientific Computing Center (DoE Contract No. DE-AC02-05cH11231). We also acknowledge use of the TIGRESS High Performance Computer Center at Princeton University. Publisher Copyright: This journal is {\textcopyright} 2020 The Royal Society of Chemistry.",
year = "2020",
month = mar,
day = "7",
doi = "10.1039/c9sc05116c",
language = "English (US)",
volume = "11",
pages = "2335--2341",
journal = "Chemical Science",
issn = "2041-6520",
publisher = "Royal Society of Chemistry",
number = "9",
}