Highly Efficient Charge Transfer between Water and Two-Dimensional Materials with Polar Bonds.

Area of Science:

• Surface Science
• Computational Chemistry
• Materials Science

Background:

• Charge transfer at solid-liquid interfaces is crucial for many applications.
• Understanding nanoscale interfacial charge transfer remains a challenge.

Purpose of the Study:

• Investigate interfacial charge transfer between water and 2D materials (graphene and hBN).
• Explore the influence of material properties on charge transfer mechanisms.

Main Methods:

• Ab initio molecular dynamics simulations were employed.
• Comparative analysis of water interaction with graphene (nonpolar) and hBN (polar).

Main Results:

• hBN shows ~10x higher charge transfer with water than graphene, contrary to expectations.
• Water's hydrogen-down orientation on hBN facilitates electron delocalization and migration.
• Polar B-N bonds in hBN enhance orbital overlap with water's hydrogen atoms.
• Similar charge transfer enhancement observed for polar 2D materials like GaN and AlN.
• Positive correlation found between charge transfer and bond polarity.
• Friction coefficient of water on surfaces correlates positively with charge transfer.

Conclusions:

• Materials with polar bonds, like hBN, significantly enhance interfacial charge transfer with water.
• This phenomenon is driven by specific water molecule orientation and orbital interactions.
• Polar 2D materials show promise for biochemical sensors and energy conversion devices.