Graphene oxide is a rising star among 2D materials, yet its interaction with liquid water remains a fundamentally open question: experimental characterization at the atomic scale is difficult, and modeling by classical approaches cannot properly describe chemical reactivity. Here, we bridge the gap between simple computational models and complex experimental systems, by realistic first-principles molecular simulations of graphene oxide (GO) in liquid water. We construct chemically accurate GO models and study their behavior in water, showing that oxygen-bearing functional groups (hydroxyl and epoxides) are preferentially clustered on the graphene oxide layer. We demonstrated the specific properties of GO in water, an unusual combination of both hydrophilicity and fast water dynamics. Finally, we evidence that GO is chemically active in water, acquiring an average negative charge of the order of 10 mC m⁻². The ab initio modeling highlights the uniqueness of GO structures for applications as innovative membranes for desalination and water purification.

氧化石墨烯是2D材料中的一颗冉冉升起的新星，但它与液态水的相互作用仍然是一个根本性的开放性问题：在原子尺度上进行实验表征非常困难，并且通过经典方法进行建模无法正确描述化学反应性。在这里，我们通过对液态水中氧化石墨烯（GO）进行逼真的第一原理分子模拟，弥合了简单计算模型与复杂实验系统之间的鸿沟。我们构建化学上准确的GO模型并研究它们在水中的行为，表明含氧官能团（羟基和环氧化物）优先聚集在氧化石墨烯层上。我们证明了GO在水中的特殊特性，即亲水性和快速水动力学的非凡组合。最后，我们证明GO在水中具有化学活性，⁻²。从头开始的建模突出了GO结构的独特性，可作为脱盐和水净化的创新膜应用。