| AVS 63rd International Symposium & Exhibition | |
| In-Situ and Operando Spectroscopy and Microscopy for Catalysts, Surfaces, & Materials Focus Topic | Thursday Sessions |
| Session IS-ThP |
| Session: | In-Situ and Operando Spectroscopy and Microscopy for Catalysts, Surfaces, & Materials Poster Session |
| Presenter: | Sefik Suzer, Bilkent University, Turkey |
| Authors: | M.T. Camci, Mrs, Turkey P. Aydogan, Bilkent University, Turkey B. Ulgut, Bilkent University, Turkey C. Kocabas, Bilkent University, Turkey S. Suzer, Bilkent University, Turkey |
| Correspondent: | Click to Email |
X-ray photoelectron spectroscopic (XPS) investigation of charge screening across two gold electrodes fabricated on a porous polymer surface which is impregnated with an ionic liquid (IL) will be presented. The IL provides a sheet of conducting layer to the insulating polymer film, and allows monitoring charging and screening dynamics at the polymer + IL / vacuum interface in a laterally resolved fashion across the electrodes. Time-resolved measurements are also implemented by recording F1s peak of the IL, while imposing 10 mHz square-wave-pulses (SQW) across the two electrodes in source-drain geometry. Variations in the F1s binding energy reflects directly the transient local electrical potential, and allow us visualize screening of the otherwise built-in local voltage drop on and across the metal electrodes in the range of millimeters. Accordingly, the device is partitioned into two oppositely polarized regions, each following polarization of one electrode through the IL medium. On the other extreme, upon imposing a relatively fast 1 kHz square-wave pulses the charge screening is prevented and the device is brought to assume a simple resistor role. The presented structure and variants of XPS measurements, enabling to record voltage transients in unexpectedly large lateral distances away from the interface(s), can impact on understanding of various electrochemical concepts.