Mouhat Félix, Coudert François-Xavier, Bocquet Marie-Laure
PASTEUR, Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 24 Rue Lhomond 75005, Paris, France.
Chimie ParisTech, PSL University, CNRS, Institut de Recherche de Chimie Paris, 75005, Paris, France.
Nat Commun. 2020 Mar 26;11(1):1566. doi: 10.1038/s41467-020-15381-y.
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. The ab initio modeling highlights the uniqueness of GO structures for applications as innovative membranes for desalination and water purification.
氧化石墨烯是二维材料中的一颗新星，然而其与液态水的相互作用在根本上仍是一个悬而未决的问题：在原子尺度上进行实验表征很困难，而用经典方法进行建模又无法恰当地描述化学反应活性。在此，我们通过对液态水中的氧化石墨烯（GO）进行逼真的第一性原理分子模拟，弥合了简单计算模型与复杂实验系统之间的差距。我们构建了化学精确的GO模型并研究其在水中的行为，结果表明含氧化官能团（羟基和环氧基）优先聚集在氧化石墨烯层上。我们展示了GO在水中的特殊性质，即亲水性和快速水动力学的非同寻常组合。最后，我们证明GO在水中具有化学活性，获得了约10 mC m数量级的平均负电荷。从头算建模突出了GO结构在作为创新型脱盐和水净化膜应用方面的独特性。
