IN-SITU OBSERVATION OF OXYGEN ADLAYER FORMATION ON CU(110) ELECTRODE SURFACES

In-situ atomic force microscopy (AFM) was used to image Cu(110) single crystals in aqueous solutions during the initial stages of oxidation. Images obtained in pH 2.5-2.7 HClO4 and H2SO4 solutions revealed the growth of oxygen adlayers consisting primarily of [001] oriented chain s. A majority of these chains (ca. 70%) were arranged in (2 x 1) and ( 3 x 1) structures. These chain structures were observed in the thermod ynamically forbidden region of the pH-potential phase diagram, which i ndicates that stable oxygen adlayers develop prior to bulk oxide forma tion.