石墨烯缺陷处的水分解
Breaking Water at Graphene Defects
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中文总结 AI 辅助
本研究利用机器学习原子间势探究缺陷石墨烯-水界面的水分解，发现溶剂化开启两条竞争反应路径，产生不同中间体并增强吸附，揭示碳空位丰富的界面化学及其对功能化和输运的意义。
中文摘要 AI 辅助
固体表面的水分解支撑着从腐蚀、催化到电化学和光伏等一系列过程。缺陷通常作为分解反应的活性位点，然而溶剂化如何影响这些位点上的水分解仍知之甚少。在此，我们使用最先进的机器学习原子间势来探索缺陷石墨烯-水界面处的水分解。我们表明，溶剂化定性地改变了石墨烯单空位（SV）处的反应机理，开辟了孤立水分子所不具备的路径。气相过程通过单一协同通道进行，而溶剂化的SV通过两条竞争路径分解水：一条碱性路径形成SV-H和OH-(aq)，以及一条酸性路径形成SV-OH和H3O+(aq)。这些较低能垒的路径产生不同的化学吸附中间体，增强了石墨烯-水的吸附。因此，即使是一个简单的碳空位也会产生出乎意料的丰富界面化学，将表面化学与界面电荷和润湿性耦合起来，对碳功能化和纳米流体输运具有重要意义。
英文摘要
Water dissociation at solid surfaces underpins processes ranging from corrosion and catalysis to electrochemistry and photovoltaics. Defects often serve as reactive sites for dissociation, yet how solvation influences water dissociation at such sites remains poorly understood. Here, we use state-of-the-art machine-learned interatomic potentials to explore water dissociation at defective graphene-water interfaces. We show that solvation qualitatively changes the reaction mechanism at a graphene single vacancy (SV), opening pathways that are absent for an isolated water molecule. Whereas the gas-phase process proceeds via a single concerted channel, the solvated SV splits water through two competing pathways: a basic route forming SV-H and OH-(aq), and an acidic route forming SV-OH and H3O+(aq). These lower-barrier pathways produce distinct chemisorbed intermediates that enhance graphene-water adsorption. Accordingly, even a simple carbon vacancy gives rise to unexpectedly rich interfacial chemistry, coupling surface chemistry to interfacial charge and wettability, with implications for carbon functionalization and nanofluidic transport.
