Surface reconstruction during the adsorption/desorption of OH species onto Cu(111) and Cu(100) in O. 1 M NaOH solution

Abstract

The process of adsorption/desorption of OH- species onto Cu(111) and Cu(100) in 0.1M NaOH solution has been investigated by cyclic voltammetry and the potentiostatic pulse technique. Investigation of the electrochemical behavior of the Cu(100) face in 0.1M NaOH solution was performed for the first time in this work. It was shown that the adsorption/ desorption of OH species occurs in the potential range between ?1.13 V vs. SHE and ?0.83V vs SHE forming an adsorbate of low coverage. It was shown that in 0.1MNaOHsolution irreversible surface reconstruction of the Cu(111) face occurs as a consequence of the adsorption/desorption of OH- species. The original surface cannot be restored even if the electrode is exposed to potentials more positive than ?0.53 V vs. SHE for some time. If this time is, in the case of repetitive pulse experiments, equal or smaller than 10 s reconstruction does not occur. Adsorption of OH- species takes place in the potential range more negative than ?0.6 V vs. SHE only on reconstructed surfaces. For this process to occur onto non-reconstructed, original Cu(111) surfaces, higher overpotentials are needed.