Early Stages of Electrochemical Oxidation of Cu(111) and Polycrystalline Cu Surfaces Revealed by in Situ Raman Spectroscopy

Nataraju Bodappa; Min Su; Yu Zhao; Jia-Bo Le; Wei-Min Yang; Petar Radjenovic; Jin-Chao Dong; Jun Cheng; Zhong-Qun Tian; Jian-Feng Li

doi:10.1021/jacs.9b04638

Early Stages of Electrochemical Oxidation of Cu(111) and Polycrystalline Cu Surfaces Revealed by in Situ Raman Spectroscopy

J Am Chem Soc. 2019 Aug 7;141(31):12192-12196. doi: 10.1021/jacs.9b04638. Epub 2019 Jul 25.

Authors

Nataraju Bodappa¹, Min Su¹, Yu Zhao¹, Jia-Bo Le¹, Wei-Min Yang², Petar Radjenovic¹, Jin-Chao Dong¹, Jun Cheng¹, Zhong-Qun Tian¹, Jian-Feng Li^{1

2}

Affiliations

¹ MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering , Xiamen University , Xiamen 361005 , China.
² Department of Physics , Xiamen University , Xiamen 361005 , China.

PMID: 31328527
DOI: 10.1021/jacs.9b04638

Abstract

Investigating the chemical nature of the adsorbed intermediate species on well-defined Cu single crystal substrates is crucial in understanding many electrocatalytic reactions. Herein, we systematically study the early stages of electrochemical oxidation of Cu(111) and polycrystalline Cu surfaces in different pH electrolytes using in situ shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS). On Cu(111), for the first time, we identified surface OH species which convert to chemisorbed "O" before forming Cu₂O in alkaline (0.01 M KOH) and neutral (0.1 M Na₂SO₄) electrolytes; while at the Cu(poly) surface, we only detected the presence of surface hydroxide. Whereas, in a strongly acidic solution (0.1 M H₂SO₄), sulfate replaces the hydroxyl/oxy species. This results improves the understanding of the reaction mechanisms of various electrocatalytic reactions.