The interface between HOPG and 1-butyl-3-methyl-imidazolium hexafluorophosphate

Abstract

The interface between highly oriented pyrolytic graphite (HOPG) and 1-butyl-3-metyl-imidazolium hexafluorophosphate (BMIPF6) has been studied using cyclic voltammetry, electrochemical impedance spectroscopy, immersion charge measurements and in-situ scanning tunneling microscopy (insitu STM). The results are compared with those obtained with Au(100) in BMIPF6 (Phys.Chem.Chem.Phys., 2011, 13, 11627). The main result is that the high frequency capacitance spectra on the two systems are similar to each other, however at low frequencies some slow interfacial processes cause the appearance of a second capacitance arc on Au(100), which is absent for HOPG. The slow processes are attributed to the rearrangement of the Au surface structure and to the formation of ionic liquid adlayers -these are visualized by in-situ STM.

Electrochemical impedance spectroscopy in interfacial studies

“…As evidenced by in-situ STM imaging, contrary to a rigid and inert structure of the HOPG surface, the Au(100) surface in contact with ILs undergoes a slow rearrangement phenomena and a distinct corrosion processes. These findings explain the presence and absence of of Z 2 in the equivalent circuit for Au(100) and HOPG, respectively [6]. 3.…”

The metal–ionic liquid interface as characterized by impedance spectroscopy andin situscanning tunneling microscopy

“…Since then, we have performed many measurements; the reports on these are given in ref. [31][32][33][34][35][36][37][38]. The present overview is a summary of the obtained findings, extended with new measurements, in order to draw a more complete picture of these interesting systems.…”

Static Capacitance at the Electrochemical Liquid-liquid Interface Between Ionic Liquids and Eutectic Ga-In Alloy Measured Using the Pendant Drop Method

“…In contrast to the progress of the understanding of the EDL of ILs from the theoretical side, experimental confirmation of the predicted IL-peculiar behavior is not straightforward. It has been found, from studies using electrochemical impedance spectroscopy (EIS), that C for the EDL of ILs has strong frequency dependence [11][12][13][14][15][16][17][18] and shows potential hysteresis, 11,[19][20][21] both of which seem to result from the structural ordering of IL interface [22][23][24][25][26][27][28][29] and the ultraslow dynamics [29][30][31][32][33][34][35][36][37][38] of such ordered structure. These tendencies have hampered rigorous evaluation of C experimentally.…”