The effect of adsorbate-adsorbate interaction on the structure of chemisorbed overlayers on TiO2(110)

The adsorption of acetic and benzoic acid on a TiO2(110) surface has been s tudied using scanning tunnelling microscopy (STM) and low energy electron d iffraction (LEED). Both acids dissociate upon adsorption at room temperatur e and with saturation coverage for both species, LEED identifies a (2 x 1) pattern. Under the same conditions. STM shows a (2 x 1) form for acetate, b ut a predominance of (2 x 2) with benzoate. It is proposed that rotation of the phenyl ring takes place, allowing the formation of dimers of benzoate at the surface. 8 1999 Elsevier Science B.V. All rights reserved.