Elucidating the Structure of the Cu-Alkaline Electrochemical Interface with the Laser-Induced Temperature Jump Method
Paula Sebastián‐Pascual, Francisco J. Sarabia, Vı́ctor Climent, Juan M. Feliú, Marı́a Escudero-Escribano
Abstract
A detailed description of the Cu–electrolyte interface is vital to understand the electrocatalytic properties of Cu surfaces. Herein, we combine cyclic voltammetry and the laser-induced temperature jump technique to describe the structure of the Cu(111) and Cu(100) | electrolyte interfaces in 0.1 M NaOH in a glass-free electrochemical cell. The laser-induced potential transients recorded at different potentials provided information of the surface charge distribution, which allowed us to calculate the potential of maximum entropy (pme), which can be considered as a good estimation of the potential of zero charge (pzc) of Cu(111) and Cu(100). We found that pzcCu(111) > pzcCu(100), following the same order as their respective work function values. Interestingly, the estimated pzc appears to be located at the onset potential of the OH* voltammetric feature for Cu(111) and Cu(100), which suggests that this feature shifts with the pzc of each crystallographic orientation. This is the first study that provides the experimental evidence of charge distribution at the Cu–solution interface under alkaline conditions.