Raman spectroelectrochemical study of electrochemical decomposition of poly(neutral red) at a gold electrode

A gold electrode, modified with poly(neutral red), has been studied with surface-enhanced resonance Raman spectroscopy at 676.4 nm excitation. It has been shown that both qualitative and quantitative changes in Raman spectra occur during prolonged holding of the modified electrode in pH 7.0 solution at a controlled electrode potential ranging from −0.6 to −0.2 V vs. Ag/AgCl, indicating that a decomposition of the poly(neutral red) layer proceeds. The decomposition proceeds slower at a more negative electrode potential. From kinetic data obtained, first-order decomposition rate constants have been calculated, ranging from 9.17 × 10−4 to 1.09 × 10−2 min−1 for electrode potential ranging from −0.6 to −0.2 V.

Graphical abstractTime resolved Raman spectra of poly(Neutral Red) at a gold electrode in pH 7.0 solution at E = −0.4 V.Figure optionsDownload full-size imageDownload as PowerPoint slide