[10a-N306-1~11] 17.2 Graphene

△ [10a-N306-3] Kelvin Probe Measurement of Water-on-Graphene Adsorption Kinetics
Modulated by Substrate Surface Modification

〇(M2)Takumu Hirose¹, Ryo Nouchi^1,2 (1.Osaka Pref. Univ., 2.JST-PRESTO)

Keywords:single layer graphene, kinetics measurement, surface modification

Single layer graphene is an ultimately thin material. This makes it a suitable platform for sensor applications. The response time of molecular sensing strongly depends on the adsorption rate of target molecules on graphene. In this talk, we report the results of measuring the adsorption kinetics of water on graphene using the Kelvin probe technique. Single layer graphene grown by CVD was transferred onto hydrophilicity-controlled SiO₂/Si substrates whose surfaces were modified with two types of silane coupling agents. From the time evolution of the measured surface potential, it was found that the adsorption rate of water on graphene on the hydrophobic substrate was slower than that on the hydrophilic substrate. It was also found that the surface potential of graphene on the hydrophobic substrate recovered to its original value when the exposure to water molecules was stopped, but the surface potential of graphene on the hydrophilic substrate did not completely return.