The adsorption of aromatic acids onto the graphite basal surface

The adsorption of benzoic acid, toluic acid, and salicylic acid from solution onto the graphite basal surface has been studied using atomic force microscopy (AFM). A systematic study of these three related planar aromatic acids is conducted in order to observe the influence of the functional side-group upon adsorption. It is found that upon adsorption all three acids orient with the benzene ring parallel to the graphite surface. On the graphite terraces, the benzoic acid decoration follows a Stranski–Krastanov growth mode whereas toluic acid follows Volmer–Weber growth. Salicylic acid forms a fibrous aggregate network. In addition to the terraces, graphite steps and near-surface bulk defects are found to be important sites for adsorption. The AFM tip is used to create irreversible nanoscale modifications of adsorbate structures.