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.