Two-dimensional ice-like water adlayers on a mica surface with and without a graphene coating under ambient conditions

• Published in: Nanoscale Vol. 16; no. 24; pp. 11542 - 11549
• Main Authors: Li, Xiaojiao, Fang, Ye-Guang, Bai, Qi, Jiang, Jian, Zeng, Xiao Cheng, Francisco, Joseph S, Zhu, Chongqin, Fang, Weihai
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 20.06.2024
• Subjects: Bilayers; Coating; Deicing; Electrochemistry; Graphene; Hydrogen bonding; Hydrogen bonds; Mica; Microscopy; Molecular dynamics; Water chemistry
• ISSN: 2040-3364; 2040-3372; 2040-3372
• DOI: 10.1039/d4nr00748d

Water tends to wet all hydrophilic surfaces under ambient conditions, and the first water adlayers on solids are important for a broad range of physicochemical phenomena and technological processes, including corrosion, wetting, lubrication, anti-icing, catalysis, and electrochemistry. Unfortunately, challenges in characterizing the first water adlayer in the laboratory have hampered molecular-level understanding of the contact water structure. Herein, we present the first ab initio molecular dynamics simulation evidence of a previously unreported ice-like adlayer structure (named as Ice-AL-II) on a prototype mica surface under ambient conditions. Calculation showed that the newly identified Ice-AL-II structure is more stable than the widely recognized ice-adlayer structure on mica surfaces (named as Ice-AL-I). Ice-AL-II exhibited a face-centered corner-cut tetragon (or a face-centered irregular pentagon) pattern of a hydrogen-bonded network. The center of the corner-cut tetragon was occupied by either a K + cation or a water molecule with two H atoms pinned by the mica (100) via double hydrogen bonds. Our simulation also suggested that bilayer Ice-AL-II favors AA stacking rather than AB stacking. Interestingly, when a graphene sheet was coated on top of the ice-like adlayer, the stability of Ice-AL-II was further enhanced. In contrast, due to its strongly puckered structure, the Ice-AL-I structure could be crushed into a near-Ice-AL-II structure by the graphene coating. Ice-AL-II is thus proposed as a promising candidate for the ice-like structure on a mica surface detected by scanning polarization force microscopy and by atomic force microscopy between a graphene coating and a mica surface. Ab initio molecular dynamics simulations show that a previously unreported two-dimensional ice-like water adlayer structure, termed Ice-AL-II, can form on mica surfaces under ambient conditions.