Analyzing the Adsorption Behavior of Thiocyanide on Pure Pt and Ni Electrode Surfaces by Confocal Microprobe Raman Spectroscopy

Abstract

Thiocyanide ion adsorption on Pt and Ni electrode surfaces was investigated by confocal Raman microscopy. The effects on the adsorption behavior of SCN^- by the electrolyte anion, concentration and applied potential were studied. The potential has a significant effect on the frequency shift of SCN^- as a result of the electrochemical Stark effect. The adsorbability of the electrolyte anion has a significant influence on the surface Raman intensity of SCN^-; the intensity follows the order Cl^-<ClO₄^-<F^-. It can be explained in terms of competitive adsorption between the SCN^- and the anion. It has been shown that surface Raman spectroscopy can be a sensitive tool for the in-situ analysis of the surface species and its configuration, such as surface complexes and films on transition metal electrodes.