Dynamic Equilibrium at the HCOOH-Saturated TiO<sub>2</sub>(110)–Water Interface
Fernanda Brandalise Nunes, Nicoló Comini, J. Trey Diulus, Thomas Huthwelker, Marcella Iannuzzi, Jürg Osterwalder, Zbyněk Novotný
Abstract
High Resolution Image Download MS PowerPoint Slide Carboxylic acids bind to titanium dioxide (TiO 2 ) dissociatively, forming surface superstructures that give rise to a (2 × 1) pattern detected by low-energy electron diffraction. Exposing this system to water, however, leads to a loss of the highly ordered surface structure. The formate-covered surface was investigated by a combination of diffraction and spectroscopy techniques, together with static and dynamic ab initio simulations, with the conclusion that a dynamic equilibrium exists between adsorbed formic acid and water molecules. This equilibrium process is an important factor for obtaining a better understanding of controlling the self-cleaning properties of TiO 2, because the formic acid monolayer is responsible for the amphiphilic character of the surface.