Early Stages of Electrochemical Oxidation of Cu(111) and Polycrystalline Cu Surfaces Revealed by in Situ Raman Spectroscopy
Early Stages of Electrochemical Oxidation of Cu(111) and Polycrystalline Cu Surfaces Revealed by in Situ Raman Spectroscopy
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原位拉曼光谱揭示 Cu(111) 和多晶铜表面电化学氧化的早期阶段
DOI：
10.1021/jacs.9b04638
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发表时间：
2019-08-07
影响因子：
15
通讯作者：
Li, Jian-Feng
中科院分区：
文献类型：
--
作者：
Bodappa, Nataraju;Su, Min;Li, Jian-Feng
研究在明确的铜单晶基底上吸附的中间物种的化学性质对于理解许多电催化反应至关重要。在此，我们使用原位壳层隔绝纳米粒子增强拉曼光谱（SHINERS）系统地研究了在不同pH值电解液中Cu(111)和多晶铜表面电化学氧化的早期阶段。在Cu(111)上，我们首次确定了表面OH物种，它在碱性（0.01 M KOH）和中性（0.1 M Na₂SO₄）电解液中形成Cu₂O之前会转变为化学吸附的“O”；而在多晶铜表面，我们只检测到表面氢氧化物的存在。然而，在强酸性溶液（0.1 M H₂SO₄）中，硫酸盐取代了羟基/氧物种。这一结果增进了对各种电催化反应机制的理解。
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.