Electrochemical Potential Stabilization of Reconstructed Au(111) Structure by Monolayer Coverage with Graphene.
The electrochemical properties of a monolayer graphene grown on a Au(111) electrode were studied using cyclic voltammetry (CV) and electrochemical scanning tunneling microscopy (EC-STM). CV and EC-STM measurements in 0.1 M H2SO4 aqueous solution revealed that graphene grown on the reconstructed (22 × √3) Au(111) structure effectively inhibited potential-induced structural transitions between reconstructed (22 × √3) and unreconstructed (1 × 1), and the adsorption/desorption of SO4(2-) ions, which are intrinsic behavior of the bare Au(111) surface. The underlying reconstructed structure was significantly stabilized by covering with monolayer graphene over a wide potential range between -0.2 V and +1.35 V vs Ag/AgCl (saturated KCl), which is much wider than that for bare Au(111) (-0.2 to + 0.35 V vs Ag/AgCl (saturated KCl)). Such high stability has not been reported to date; therefore, these results are considered to be important for understanding the fundamentals of surface reconstruction and also serve to open a new branch of electrochemistry related to graphene/metal-electrolyte interfaces.
Department of Chemistry, Faculty of Science, Hokkaido University , Sapporo, Hokkaido 060-0810, Japan.|Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology, Kawaguchi, Saitama 332-0012, Japan.
Satoshi
S
Yasuda
Department of Chemistry, Faculty of Science, Hokkaido University , Sapporo, Hokkaido 060-0810, Japan.
Ryota
R
Kumagai
Department of Chemistry, Faculty of Science, Hokkaido University , Sapporo, Hokkaido 060-0810, Japan.
Koji
K
Nakashima
Department of Chemistry, Faculty of Science, Hokkaido University , Sapporo, Hokkaido 060-0810, Japan.
Kei
K
Murakoshi
Au(111); Electrochemical scanning tunneling microscopy (EC-STM); chemical vapor deposition; electrochemistry; graphene; graphene-metal interface; reconstructed surface