Hong GLaboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich , Sonneggstrasse 3, 8092 Zurich, Switzerland.
Han YInstitute of Mineral Engineering, Division of Materials Science and Engineering, Faculty of Georesources and Materials Engineering, RWTH Aachen University , 52064 Aachen, Germany.
Schutzius TMLaboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich , Sonneggstrasse 3, 8092 Zurich, Switzerland.
Wang YInstitute of Functional Nano & Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology, Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University , Suzhou, Jiangsu 215123, P. R. China.
Pan YLaboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich , Sonneggstrasse 3, 8092 Zurich, Switzerland.
Hu MInstitute of Mineral Engineering, Division of Materials Science and Engineering, Faculty of Georesources and Materials Engineering, RWTH Aachen University , 52064 Aachen, Germany.
Jie JInstitute of Functional Nano & Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology, Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University , Suzhou, Jiangsu 215123, P. R. China.
Sharma CSLaboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich , Sonneggstrasse 3, 8092 Zurich, Switzerland.
Müller UEmpa, Swiss Federal Laboratories for Materials Science and Technology , Laboratory for Nanoscale Materials Science, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland.
Poulikakos DLaboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich , Sonneggstrasse 3, 8092 Zurich, Switzerland.
English
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.