Comparison of H<sub>2</sub>O Adsorption and Dissociation Behaviors on Rutile (110) and Anatase (101) Surfaces Based on ReaxFF Molecular Dynamics Simulation
The relationship between structure and reactivity plays a dominant role in water dissociation on the various TiO<sub>2</sub> crystallines. To observe the adsorption and dissociation behavior of H<sub>2</sub>O, the reaction force field (ReaxFF) is used to investigate the dynam...
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MDPI AG
2023-09-01
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| author | He Zhou Heng Zhang Shiling Yuan |
| author_facet | He Zhou Heng Zhang Shiling Yuan |
| author_sort | He Zhou |
| collection | DOAJ |
| description | The relationship between structure and reactivity plays a dominant role in water dissociation on the various TiO<sub>2</sub> crystallines. To observe the adsorption and dissociation behavior of H<sub>2</sub>O, the reaction force field (ReaxFF) is used to investigate the dynamic behavior of H<sub>2</sub>O on rutile (110) and anatase (101) surfaces in an aqueous environment. Simulation results show that there is a direct proton transfer between the adsorbed H<sub>2</sub>O (H<sub>2</sub>O<sub>ad</sub>) and the bridging oxygen (O<sub>br</sub>) on the rutile (110) surface. Compared with that on the rutile (110) surface, an indirect proton transfer occurs on the anatase (101) surface along the H-bond network from the second layer of water. This different mechanism of water dissociation is determined by the distance between the 5-fold coordinated Ti (Ti<sub>5c</sub>) and O<sub>br</sub> of the rutile and anatase TiO<sub>2</sub> surfaces, resulting in the direct or indirect proton transfer. Additionally, the hydrogen bond (H-bond) network plays a crucial role in the adsorption and dissociation of H<sub>2</sub>O on the TiO<sub>2</sub> surface. To describe interfacial water structures between TiO<sub>2</sub> and bulk water, the double-layer model is proposed. The first layer is the dissociated H<sub>2</sub>O on the rutile (110) and anatase (101) surfaces. The second layer forms an ordered water structure adsorbed to the surface O<sub>br</sub> or terminal OH group through strong hydrogen bonding (H-bonding). Affected by the H-bond network, the H<sub>2</sub>O dissociation on the rutile (110) surface is inhibited but that on the anatase (101) surface is promoted. |
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| spelling | doaj.art-7748bf2892964322ae860f2c3ef453402023-11-19T14:46:03ZengMDPI AGMolecules1420-30492023-09-012819682310.3390/molecules28196823Comparison of H<sub>2</sub>O Adsorption and Dissociation Behaviors on Rutile (110) and Anatase (101) Surfaces Based on ReaxFF Molecular Dynamics SimulationHe Zhou0Heng Zhang1Shiling Yuan2Key Lab of Colloid and Interface Chemistry, Shandong University, Jinan 250100, ChinaKey Lab of Colloid and Interface Chemistry, Shandong University, Jinan 250100, ChinaKey Lab of Colloid and Interface Chemistry, Shandong University, Jinan 250100, ChinaThe relationship between structure and reactivity plays a dominant role in water dissociation on the various TiO<sub>2</sub> crystallines. To observe the adsorption and dissociation behavior of H<sub>2</sub>O, the reaction force field (ReaxFF) is used to investigate the dynamic behavior of H<sub>2</sub>O on rutile (110) and anatase (101) surfaces in an aqueous environment. Simulation results show that there is a direct proton transfer between the adsorbed H<sub>2</sub>O (H<sub>2</sub>O<sub>ad</sub>) and the bridging oxygen (O<sub>br</sub>) on the rutile (110) surface. Compared with that on the rutile (110) surface, an indirect proton transfer occurs on the anatase (101) surface along the H-bond network from the second layer of water. This different mechanism of water dissociation is determined by the distance between the 5-fold coordinated Ti (Ti<sub>5c</sub>) and O<sub>br</sub> of the rutile and anatase TiO<sub>2</sub> surfaces, resulting in the direct or indirect proton transfer. Additionally, the hydrogen bond (H-bond) network plays a crucial role in the adsorption and dissociation of H<sub>2</sub>O on the TiO<sub>2</sub> surface. To describe interfacial water structures between TiO<sub>2</sub> and bulk water, the double-layer model is proposed. The first layer is the dissociated H<sub>2</sub>O on the rutile (110) and anatase (101) surfaces. The second layer forms an ordered water structure adsorbed to the surface O<sub>br</sub> or terminal OH group through strong hydrogen bonding (H-bonding). Affected by the H-bond network, the H<sub>2</sub>O dissociation on the rutile (110) surface is inhibited but that on the anatase (101) surface is promoted.https://www.mdpi.com/1420-3049/28/19/6823water dissociationhydrogen bond networkTiO<sub>2</sub>ReaxFFmolecular dynamics simulation |
| spellingShingle | He Zhou Heng Zhang Shiling Yuan Comparison of H<sub>2</sub>O Adsorption and Dissociation Behaviors on Rutile (110) and Anatase (101) Surfaces Based on ReaxFF Molecular Dynamics Simulation Molecules water dissociation hydrogen bond network TiO<sub>2</sub> ReaxFF molecular dynamics simulation |
| title | Comparison of H<sub>2</sub>O Adsorption and Dissociation Behaviors on Rutile (110) and Anatase (101) Surfaces Based on ReaxFF Molecular Dynamics Simulation |
| title_full | Comparison of H<sub>2</sub>O Adsorption and Dissociation Behaviors on Rutile (110) and Anatase (101) Surfaces Based on ReaxFF Molecular Dynamics Simulation |
| title_fullStr | Comparison of H<sub>2</sub>O Adsorption and Dissociation Behaviors on Rutile (110) and Anatase (101) Surfaces Based on ReaxFF Molecular Dynamics Simulation |
| title_full_unstemmed | Comparison of H<sub>2</sub>O Adsorption and Dissociation Behaviors on Rutile (110) and Anatase (101) Surfaces Based on ReaxFF Molecular Dynamics Simulation |
| title_short | Comparison of H<sub>2</sub>O Adsorption and Dissociation Behaviors on Rutile (110) and Anatase (101) Surfaces Based on ReaxFF Molecular Dynamics Simulation |
| title_sort | comparison of h sub 2 sub o adsorption and dissociation behaviors on rutile 110 and anatase 101 surfaces based on reaxff molecular dynamics simulation |
| topic | water dissociation hydrogen bond network TiO<sub>2</sub> ReaxFF molecular dynamics simulation |
| url | https://www.mdpi.com/1420-3049/28/19/6823 |
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