Dynamic Equilibrium at the HCOOH-Saturated TiO2(110)-Water Interface

Carboxylic acids bind to titanium dioxide (TiO2) dissociatively, forming surface superstructures that give rise to a (2 x 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 TiO2, because the formic acid monolayer is responsible for the amphiphilic character of the surface.

Automated summary

Carboxylic acids can bind to titanium dioxide (TiO2) and form surface superstructures, but exposure to water leads to loss of the ordered surface structure. Research shows that a dynamic equilibrium exists between adsorbed formic acid and water molecules on the formate-covered surface. Understanding and controlling this equilibrium process is crucial for enhancing the self-cleaning properties of TiO2.