The interface between Au(1 0 0) and 1-butyl-3-methyl-imidazolium-bis(trifluoromethylsulfonyl)imide

• The interface of Au(1 0 0) and an ionic liquid has been studied.
• The double layer rearrangement processes are very slow.
• Ordered adlayers of cations and anions of the ionic liquid have been imaged by STM.

The electrochemical interface of Au(1 0 0) and an ionic liquid, BMITf2N, has been characterized by cyclic voltammetry, electrochemical impedance spectroscopy and in situ STM with the aim to compare this particular electrochemical system with the Au(1 0 0)|BMIPF6 electrode. It is demonstrated that the two systems share the same electrochemical features: the capacitance spectra around the pztc show a double-arc structure on the complex plane, and the high frequency capacitance limits are practically the same in both systems. The double layer rearrangement processes are very slow; they proceed with time constants of minutes. Ordered adlayers of cations and anions have been imaged by in situ STM.