# Insights into the Hydration Layer of Reduced Graphene Oxides: A Computational Study

## TL;DR

This study explores how water interacts with reduced graphene oxide, showing how oxygen groups affect its water-attracting properties and potential uses in water-based technologies.

## Contribution

The study reveals the atomic-scale relationship between rGO's oxidation level and its hydrophilicity through detailed simulations.

## Key findings

- Higher oxidation levels in rGO lead to stronger hydrogen bonding with water molecules.
- Water confined between rGO layers shows lateral self-diffusion similar to bulk water.
- Oxygen-containing functional groups directly influence rGO's wettability and hydration behavior.

## Abstract

Reduced graphene oxide (rGO) has emerged as a versatile material with diverse applications, particularly in aqueous environments. Understanding its interactions with water molecules is crucial for various fields, ranging from energy storage to sensing. In this study, we investigate the behavior of graphene and rGO in water, focusing on elucidating their wetting properties and the influence of oxygen‐containing functional groups. Through extensive molecular dynamics simulations, we analyze the orientation and electrostatic dipole of water molecules near the rGO interface, revealing a direct correlation between rGO hydrophilicity and oxidation level. Specifically, we observe stronger hydrogen bonding networks near higher coverage rGO monolayers, indicating enhanced hydrophilicity. Furthermore, by studying water confined between rGO layers, we find uniform water transport with lateral self‐diffusion coefficients comparable to bulk water, highlighting the potential of rGO membranes in various applications. Our findings provide insights into the atomic‐scale interactions governing rGO‐water interfaces, paving the way for the rational design of graphene‐based materials for application in aqueous environments.

The hydration behavior of reduced graphene oxide (rGO) is studied using ab initio molecular dynamics simulations, revealing the role of oxygen‐containing functional groups in determining rGO′s wettability.