Molecular level insight on the adsorption of carboxylic acids to oxide nanoparticles in aqueous solution by X-ray photoelectron spectroscopy

We show, for the first time, the ability to follow the surface chemistry (acid–base equilibrium) of a colloid nanoparticle (AlxOy@SiO2) while simultaneously monitoring the adsorption of a solute molecule (HCOOH) from solution using in situ X-ray photoelectron spectroscopy. Based on the results of the Al 2p and C 1s spectra a mechanism is proposed.