Yang Shanshan, Zhao Xiao, Qi Zhiyuan, Lu Yi-Hsien, Somorjai Gabor, Yang Peidong, Baskin Artem, Prendergast David, Salmeron Miquel
Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Department of Materials Science and Engineering, University of California-Berkeley, Berkeley, California 94720, United States.
ACS Appl Mater Interfaces. 2022 Feb 2;14(4):6093-6101. doi: 10.1021/acsami.1c15808. Epub 2022 Jan 21.
The structure and composition of copper surfaces in aqueous solutions of benzotriazole (BTAH) and NaCl was investigated by sum frequency vibrational spectroscopy as a function of concentration and bias during cyclic voltammetry experiments. We found that the protection provided by the BTAH films formed at the copper surface is effective for negative bias voltages below the open circuit potential (OCP) but not at positive voltages where Cl displaces BTAH. By measuring the Gibbs adsorption energy of BTAH and Cl, we found that a particularly stable Cl structure is formed around the OCP, suggesting that electronegative additives that move the OCP to higher negative values can improve BTAH protection, which we confirmed by the addition of a negatively charged sodium dodecyl sulfate surfactant.
在循环伏安法实验中，通过和频振动光谱研究了苯并三唑（BTAH）和氯化钠水溶液中铜表面的结构与组成，该研究是作为浓度和偏压的函数进行的。我们发现，在铜表面形成的BTAH膜所提供的保护作用，对于低于开路电位（OCP）的负偏压是有效的，但在正电压下，Cl会取代BTAH，此时保护作用失效。通过测量BTAH和Cl的吉布斯吸附能，我们发现在OCP附近形成了一种特别稳定的Cl结构，这表明将OCP移至更高负值的电负性添加剂可以改善BTAH的保护作用，我们通过添加带负电荷的十二烷基硫酸钠表面活性剂证实了这一点。
