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

Abstract

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.

Dynamic dissolution of Cm3+ ions incorporated at the calcite–water interface: an ab initio molecular dynamics simulation study

“…To explore the free-energy landscape of the dissolution process, we employed the ab initio metadynamics approach 51–54 implemented in CP2K, 55 which has been applied previously for studying various chemical processes. 56–58 In the ab initio metadynamics simulations, we applied two-dimensional collective variables (CVs) to monitor the dissolution process. Each collective variable represented the mean number of oxygen atoms coordinated with the Cm atom.…”