| AVS 63rd International Symposium & Exhibition | |
| Surface Science | Thursday Sessions |
| Session SS-ThM |
| Session: | Chirality and Enantioselectivity on Surfaces; Ionic Liquid Interfaces |
| Presenter: | Michael Wagstaffe, University of Manchester, UK |
| Correspondent: | Click to Email |
Ionic liquids are room temperature molten salts comprised entirely of cations and anions. They have an array of unique physico-chemical properties that have led to their use in a wide variety of electrochemical systems.[1] These include actuators, corrosion inhibitors, energy storage for batteries, supercapacitors, displays and as the electrolyte in photovoltaic devices. Both the function and performance of devices employing ionic liquids are dependent on how the ionic liquid behaves at phase boundaries, interfaces and near interfacial areas. Previous studies have shown that ionic liquids have a tendency to self organize at the IL/solid interface.[2] Such ordering has been shown to reduce the barrier to charge injection when ionic liquids are used in oxide solar cells.[3] As such, the ordering and chemistry of ionic liquids at the anatase TiO2(101) surface is of some interest since this is the dominant surface in mesoporous TiO2 films used in dye sensitized solar cells.
Although there is a growing body of work on the surface chemistry of bulk ionic liquids studied by photoelectron spectroscopy, studies of their interaction with solid surfaces are still relatively rare. On this basis, in an attempt to address the gap in the work, we adopted a surface science approach in which we utilized a combination of X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. From this we were able to successfully determine the orientation of the cation on the surface of anatase(101), at both high and low coverage, and also the manner in which it adsorbs. Additionally, a surface induced degradation reaction of the anion was observed at room temperature.
[1] K. R. J. Lovelock et al.Chem. Rev., 2010, 110, 5158–90.
[2] E. Binetti et al.J. Phys. Chem. C, 2013, 117, 12923–12929.
[3] B. R. Lee et al. J. Mater. Chem., 2011, 21, 2051.