On the Mechanism of Hydrophilicity of Graphene

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• 作者：Guo Hong ; Yang Han ; Thomas M. Schutzius ; Yuming Wang ; Ying Pan ; Ming Hu ; Jiansheng Jie ; Chander S. Sharma ; Ulrich Müller ; Dimos Poulikakos
• 刊名：Nano Letters
• 出版年：2016
• 出版时间：July 13, 2016
• 年：2016
• 卷：16
• 期：7
• 页码：4447-4453
• 全文大小：443K
• 年卷期：0
• ISSN：1530-6992

文摘

It is generally accepted that the hydrophilic property of graphene can be affected by the underlying substrate. However, the role of intrinsic vs substrate contributions and the related mechanisms are vividly debated. Here, we show that the intrinsic hydrophilicity of graphene can be intimately connected to the position of its Fermi level, which affects the interaction between graphene and water molecules. The underlying substrate, or dopants, can tune hydrophilicity by modulating the Fermi level of graphene. By shifting the Fermi level of graphene away from its Dirac point, via either chemical or electrical voltage doping, we show enhanced hydrophilicity with experiments and first principle simulations. Increased vapor condensation on graphene, induced by a simple shifting of its Fermi level, exemplifies applications in the area of interfacial transport phenomena.