Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich , Sonneggstrasse 3, 8092 Zurich, Switzerland.
Institute of Mineral Engineering, Division of Materials Science and Engineering, Faculty of Georesources and Materials Engineering, RWTH Aachen University , 52064 Aachen, Germany.
Nano Lett. 2016 Jul 13;16(7):4447-53. doi: 10.1021/acs.nanolett.6b01594. Epub 2016 Jun 3.
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.
人们普遍认为石墨烯的亲水性可以受到基底的影响。然而，内在贡献与基底贡献的作用以及相关机制仍存在激烈的争论。在这里，我们表明石墨烯的内在亲水性与其费米能级的位置密切相关，而费米能级会影响石墨烯与水分子的相互作用。基底或掺杂剂可以通过调节石墨烯的费米能级来调节其亲水性。通过化学或电电压掺杂，将石墨烯的费米能级从狄拉克点移动，我们通过实验和第一性原理模拟显示出增强的亲水性。通过简单地移动其费米能级，增加了石墨烯上的蒸汽冷凝，这例证了在界面输运现象领域的应用。
