Surface reconstruction during the adsorption/desorption of OH- species onto Cu(111) and Cu(100) in 0.1 M NaOH solution

Abstract

The process of adsorption/desorption of OH- species onto Cu(111) and Cu(100) in 0.1 M NaOH solution has been investigated by cyclic voltammetry and the potentiostatic pulse technique. Investigation of the electrochemical behavior of the Cu(100) face in 0.1 M 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 -0.83 V vs. SHE forming an adsorbate of low coverage. It was shown that in 0.1 M NaOH solution 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.