SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2021, Vol. 29 ›› Issue (3): 67-74.DOI: 10.1016/j.cjche.2020.10.028

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Structure and dynamics of water in TiO2 nano slits: The influence of interfacial interactions and pore sizes

Mingjie Wei, Yong Wang   

  1. State Key Laboratory of Materials-Oriented Chemical Engineering, and College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China
  • Received:2020-08-30 Revised:2020-10-27 Online:2021-05-13 Published:2021-03-28
  • Contact: Mingjie Wei
  • Supported by:
    Financial support from the National Key Research and Development Program of China (2017YFC0403902) and the Jiangsu Natural Science Foundations (BK20190085).

Structure and dynamics of water in TiO2 nano slits: The influence of interfacial interactions and pore sizes

Mingjie Wei, Yong Wang   

  1. State Key Laboratory of Materials-Oriented Chemical Engineering, and College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China
  • 通讯作者: Mingjie Wei
  • 基金资助:
    Financial support from the National Key Research and Development Program of China (2017YFC0403902) and the Jiangsu Natural Science Foundations (BK20190085).

Abstract: The interaction of water with TiO2 surfaces is of enduring interest because of wide applications of the TiO2 materials in aqueous environments. The structure and dynamic properties of water molecules in TiO2 nanopores are crucial as increasingly TiO2 materials are synthesized into nanoporous structures. In this work, the structural and dynamic properties of water molecules in nanoscale slit pores of TiO2 are investigated, by using three sets of force field models for the water- TiO2 interaction, as well as four TiO2 slit pore widths. It is concluded that the water- TiO2 interaction dominates the interfacial structure of water molecules, while the dynamic properties of water molecules are primarily influenced by the slit width in both interfacial and central regions. These findings indicate that both of the fluid properties and the interactions of fluids with pore wall will determine the transport properties of fluid in nanopores. If the pore size is large enough, e.g. 1.0 nm or larger in this work, the transport properties will be determined most by the fluids themselves. For the cases of pores whose sizes are in the range of interfacial region, the influences of pore size and interfacial interaction will interfere each other.

Key words: TiO2, Water, Molecular dynamics, ReaxFF, Nanopore, Transport

摘要: The interaction of water with TiO2 surfaces is of enduring interest because of wide applications of the TiO2 materials in aqueous environments. The structure and dynamic properties of water molecules in TiO2 nanopores are crucial as increasingly TiO2 materials are synthesized into nanoporous structures. In this work, the structural and dynamic properties of water molecules in nanoscale slit pores of TiO2 are investigated, by using three sets of force field models for the water- TiO2 interaction, as well as four TiO2 slit pore widths. It is concluded that the water- TiO2 interaction dominates the interfacial structure of water molecules, while the dynamic properties of water molecules are primarily influenced by the slit width in both interfacial and central regions. These findings indicate that both of the fluid properties and the interactions of fluids with pore wall will determine the transport properties of fluid in nanopores. If the pore size is large enough, e.g. 1.0 nm or larger in this work, the transport properties will be determined most by the fluids themselves. For the cases of pores whose sizes are in the range of interfacial region, the influences of pore size and interfacial interaction will interfere each other.

关键词: TiO2, Water, Molecular dynamics, ReaxFF, Nanopore, Transport