Effect of a Finite Single-Layer Graphene Sheet on Water

Area of Science:

• Materials Science
• Physical Chemistry
• Computational Physics

Background:

• Atomically flat surfaces and mesoscopic surfaces are known to induce water layering.
• Molecular dynamics simulations and experimental studies have confirmed water layering phenomena.

Purpose of the Study:

• To investigate the influence of a finite single-layer graphene sheet (SLGS) on water structure and hydrogen bonding at room temperature.
• To explore the effect of graphene sheet size and C-H interactions on water layering.

Main Methods:

• Molecular dynamics simulations were employed to examine the interaction between water and a finite SLGS.
• Simulations were conducted at room temperature, with and without short-range C-H interactions.

Main Results:

• Distinct water layering was observed near the finite SLGS, with weak structural and orientational ordering.
• Changes in hydrogen bonding, including reduced donor count in the first layer, were identified.
• Disabling C-H interactions led to broader water layers and asymmetric donor/acceptor profiles.
• Layering tendencies persisted even for small graphene sheets, but thermal fluctuations caused SLGS deformations, hindering stable layering.

Conclusions:

• Finite single-layer graphene sheets can induce water layering and alter hydrogen bonding networks.
• The size of the graphene sheet and specific atomic interactions influence the degree of water ordering.
• Room temperature thermal fluctuations pose a challenge for the formation of stable water layers on deformable graphene sheets.