1
|
Yamada T, Tawa T, Murase N, Kato HS. Formation and Structural Characterization of Two-dimensional Wetting Water Layer on Graphite (0001). J Chem Phys 2022; 157:074702. [DOI: 10.1063/5.0097760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Understanding the structure and wettability of monolayer water is essential for revealing the mechanisms of nucleation, growth, and chemical reactivity at interfaces. We have investigated the wetting layer formation of water (ice) on the graphite (0001) surface using a combination of low-energy electron diffraction (LEED) and scanning tunneling microscopy (STM). At around monolayer coverages, the LEED pattern showed a (2×2) periodicity, and the STM revealed a hydrogen-bonded hexagonal network. The lattice constant was about 9% larger than that for ice Ih/Ic crystals, and the packing density was 0.096 Å-2. These results indicate that an extended ice network is formed on graphite, different from that on metal surfaces. Graphite is hydrophobic under ambient conditions due to the airborne contaminant but is considered inherently hydrophilic for a clean surface. In this study, the hydrophilic nature of the clean surface has been investigated from a molecular viewpoint. The formation of a well-ordered commensurate monolayer supports that the interaction of water with graphite is not negligible so that a commensurate wetting layer is formed at the weak substrate-molecule interaction limit.
Collapse
Affiliation(s)
- Takashi Yamada
- Chemistry, Graduate School of Science, Osaka University Graduate School of Science Department of Chemistry, Japan
| | - Takenori Tawa
- Osaka University Graduate School of Science Department of Chemistry, Japan
| | - Natsumi Murase
- Osaka University Graduate School of Science Department of Chemistry, Japan
| | - Hiroyuki S Kato
- Osaka University Graduate School of Science Department of Chemistry, Japan
| |
Collapse
|
2
|
|
3
|
Jiang J, Gao Y, Zhu W, Liu Y, Zhu C, Francisco JS, Zeng XC. First-Principles Molecular Dynamics Simulations of the Spontaneous Freezing Transition of 2D Water in a Nanoslit. J Am Chem Soc 2021; 143:8177-8183. [PMID: 34008407 DOI: 10.1021/jacs.1c03243] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
As with bulk ices, two-dimensional (2D) ices exhibit diverse crystalline structures, and the majority of these 2D structures have been predicted based on classical molecular dynamics (MD) simulations. Here, the spontaneous freezing transition of 2D liquid water within hydrophobic nanoslits is demonstrated for the first time using first-principles MD simulations. Various 2D ices are observed under different lateral pressure and temperature conditions. Notably, the liquid water confined to a 6.0 Å-wide nanoslit can spontaneously freeze into a monolayer ice consisting of an array of zigzag water chains at 2.5 GPa and 250 K. Moreover, within an 8.0 Å-wide nanoslit and at 4.0 GPa and 300 K, a previously unreported bilayer ice forms spontaneously that has a structure resembling that of the double surface layers of bulk ice-VII. Both 2D crystalline ices do not obey the ice rule, suggesting first-principles simulation can access a certain phase space that is not easily approached using classical simulations.
Collapse
Affiliation(s)
- Jian Jiang
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Yurui Gao
- Laboratory of Theoretical and Computational Nanoscience and Technology, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Weiduo Zhu
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Yuan Liu
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Chongqin Zhu
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing, 100190, P. R. China
| | - Joseph S Francisco
- Department of Earth & Environmental Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Xiao Cheng Zeng
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| |
Collapse
|
4
|
Abstract
A highly stable ice monolayer with folded structural motifs is predicted by means of a novel tiling method augmented with ab initio calculations. This ice monolayer has every two neighboring water hexamers connected by a water square yet folded into two distinct planes, and is thus coined as a folded ice model. It is in the ground state in a range of water densities from 0.08 to 0.12 Å-2, with a stronger energy preference at a lower water density. Its stability shown by ab initio molecular dynamics simulations can sustain up to a temperature of 100 K. The tiling method also enables the prediction of a family of considerably stable ice monolayers with a variety of puckered structures. These results enrich our knowledge of low-dimensional water structures and pave a way to explore more exotic ice nanostructures under confinements.
Collapse
Affiliation(s)
- Ying Xu
- State Key Laboratory of Mechanics and Control of Mechanical Structures and Institute of Nanoscience, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing, China.
| | - Xiaoyu Xuan
- State Key Laboratory of Mechanics and Control of Mechanical Structures and Institute of Nanoscience, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing, China.
| | - Zhuhua Zhang
- State Key Laboratory of Mechanics and Control of Mechanical Structures and Institute of Nanoscience, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing, China.
| | - Wanlin Guo
- State Key Laboratory of Mechanics and Control of Mechanical Structures and Institute of Nanoscience, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing, China.
| |
Collapse
|
5
|
Zhu C, Gao Y, Zhu W, Liu Y, Francisco JS, Zeng XC. Computational Prediction of Novel Ice Phases: A Perspective. J Phys Chem Lett 2020; 11:7449-7461. [PMID: 32787287 DOI: 10.1021/acs.jpclett.0c01635] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Although computational prediction of new ice phases is a niche field in water science, the scientific subject itself is representative of two important areas in physical chemistry, namely, statistical thermodynamics and molecular simulations. The prediction of a variety of novel ice phases has also attracted general public interest since the 1980s. In particular, the prediction of low-dimensional ice phases has gained momentum since the confirmation of a number of low-dimensional "computer ice" phases in the laboratory over the past decade. In this Perspective, the research advancements in computational prediction of novel ice phases over the past few years are reviewed. Particular attention is placed on new ice phases whose physical properties or dimensional structures are distinctly different from conventional bulk ices. Specific topics include the (i) formation of superionic ices, (ii) electrofreezing of water under high pressure and in a high external electric field, (iii) prediction of low-density porous ice at strongly negative pressure, (iv) ab initio computational study of two-dimensional (2D) ice under nanoscale confinement, and (v) 2D ices formed on a solid surface near ambient temperature without nanoscale confinement. Clearly, the formation of most of these novel ice phases demands certain extreme conditions. Ongoing challenges and new opportunities for predicting new ice phases from either classical molecular dynamics simulation or high-level ab initio computation are discussed.
Collapse
Affiliation(s)
- Chongqin Zhu
- Department of Earth and Environmental Science, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Yurui Gao
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Weiduo Zhu
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
- Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yuan Liu
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Joseph S Francisco
- Department of Earth and Environmental Science, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Xiao Cheng Zeng
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
- Department of Chemical & Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| |
Collapse
|