2124
Visualizing the 2nd Layer: 4,4´-Bipyridine Adsorption on Sb(111) from EMImBF4

Tuesday, 31 May 2022: 08:40
West Meeting Room 120 (Vancouver Convention Center)
H. Ers, L. Siinor, and P. Pikma (University of Tartu)
Room temperature ionic liquids (RTIL) have had a lot of attention in modern chemical research. Due to their high stability under applied electrode potential, the wide electrochemical window and dual usability as a solvent and an electrolyte RTILs have become very attractive in the field of applied electrochemistry and modern energetics [1]. Molecular self-assembly at solid surfaces, resulting in the formation of the nanostructures with well-controlled properties and functionality reveals fascinating perspectives in science and technology at nanoscale [2]. For instance, the smart tailoring of the structural properties of the functionalized electrodes enables SAMs to be used as protective coatings and for the fabrication of organic thin-film transistors and sensors, and as triggers of specific electrochemical processes.

In this study the in situ STM and impedance spectroscopy methods have been applied to study the structure and properties of the electrochemically polished Sb(111) single crystal electrode | EMImBF4, and EMImBF4 + 1% 4,4´-bipyridine, interface.

Using in situ scanning tunnelling microscopy, the adsorption/desorption of 4,4’-bipyridine was demonstrated and a dense underlying structure, formed below a sparse self-assembled monolayer, was visualized. The detection of two separate adsorbed layers indicates that the ordering of organic molecules could extend well beyond the monolayer on the electrode’s surface. These insights are of fundamental and practical importance in the development of nanoelectronics.

References:

[1] H. Ohno (Ed.), Electrochemical Aspects of Ionic Liquids, John Wiley & Sons, Inc., New Jersey, 2005, p.1.

[2] T. Wandlowski, Phase Transitions in Two-dimensional Adlayers at Electrode Surfaces: Thermodynamics, Kinetics, and Structural Aspects, A.J. Bard, M. Stratmann (Eds.), Encyclopedia of Electrochemistry, Wiley VCH, Weinheim (2002) p. 383-471.

Acknowledgments:

This work was supported by the Estonian Research Council grant PSG249 and by the EU through the European Regional Development Fund under project TK141 (2014-2020.4.01.15-0011). For providing us with the computational resources, we would like to acknowledge the HPC Center of the University of Tartu.

See more of: L06 - Monolayers and Thin Films
See more of: L06: Electrochemistry at the Nanoscale
See more of: Physical and Analytical Electrochemistry, Electrocatalysis, and Photoelectrochemistry
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