非水体系中苯并三唑在铜电极上吸附的电化学表面增强拉曼光谱研究

采用电化学现场表面增强拉曼光谱(SERS)研究了非水体系中苯并三唑(BTAH)在铜电极上的吸附及成膜行为, 结果表明非水体系中BTAH的吸附行为随电位变化而不同. 较负电位区间主要以中性分子形式吸附; 中间电位区间主要以BTA^－吸附并不可逆成膜; 而在氧化电位区间主要表现为铜的氧化. 随中性配体三苯基膦(pph₃)的加入, 在中间电位区间, 由于易溶的Cu(pph₃)_n⁺的生成而使铜的溶解速度加快, 最终该阳离子在溶液中和BTA^-作用而生成了多核铜的配合物. 采用直接电化学方法模拟电极表面过程合成了相应的吸附产物, 并对其组成进行了相关表征.

Electrochemical Surface Enhanced Raman Spectroscopic Studies on the Adsorption of Benzotriazole at Cu Electrode in Non-aqueous Solution

The surface coordination chemistry of benzotriazole (BTAH) at copper electrode was investigated by in situ electrochemical surface enhanced Raman spectroscopy (SERS) and electrochemical synthesis in the acetonitrile solution for the first time. The surface coordination processes were researched and the surface complexes prepared by electrochemical method were characterized by microanalysis, X-ray crystallographic determination and Raman spectroscopy. The influence of the neutral ligand of triphenylphosphine (pph₃) on the adsorption and film formation process of BTAH was investigated. In situ SERS studies revealed that BTAH underwent three processes of chemical adsorption, formation of compact polymer layer and the breaking of the polymer layer due to the oxidation of copper on the surface, in which the compact polymer layer inhibited the dissolution and oxidation of copper effectively. With the introduction of pph₃ into the solution, the formation of surface polymer complex film was suppressed because of the existence of the soluble cation. The formation of complex of Cu(pph₃)_n⁺ with BTA^－ in the solution resulted in a significant increase of the dissolution of copper. The microanalysis and X-ray crystal measurements indicated its structure of Cu₅(BTA)₅(pph₃)₄Cl•2CH₃CN.