表面增强红外光谱电化学揭示电极-电解质界面处的抗衡离子效应  

Study on Counter Ion Effect at Electrode/Electrolyte Interface by Surface-enhanced Infrared Absorption Spectroelectrochemistry

作　　者：程晓伟 李姗姗 武烈[1] 姜秀娥 CHENG Xiao-Wei;LI Shan-Shan;WU Lie;JIANG Xiu-E(State Key Laboratory of Electroanalytical Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022,China;School of Applied Chemistry and Engineering,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学院长春应用化学研究所,电分析化学国家重点实验室,长春130022 [2]中国科学技术大学应用化学与工程学院,合肥230026

出　　处：《分析化学》2022年第3期365-374,共10页Chinese Journal of Analytical Chemistry

基　　金：中国科学院青年创新促进会项目(No.2020233);国家自然科学基金项目(Nos.22025406,22074138);吉林省科技发展计划项目(No.20200703021ZP)资助。

摘　　要：选用4种中性电化学反应体系中常用的电解质,利用表面增强红外吸收光谱电化学技术结合振动斯塔克效应对电极-电解质溶液界面处特殊的抗衡离子效应进行谱学-电化学表征。应用不同分子长度的振动斯塔克探针,揭示了阴离子作为抗衡离子,因与电极表面相互作用强度的差异而在双电层中具有不同的浓度分布,进而对界面局域电场产生不同的屏蔽效应。与电极表面存在特异性相互作用的离子可大量吸附到紧密层,使界面局域有效电场强度显著降低。此外,本研究还提出了定量分析离子与电极界面相互作用程度的方法。本研究结果对进一步理解电化学双电层的结构以及电催化反应的构效关系具有重要意义。The electrode-electrolyte interface is very important in electrochemistry,but the quantitative analysis of the adsorption of counter ions on the electrode surface and its influence on the interfacial electric field is extremely lacking,which limits the in-depth understanding of the electrode-electrolyte interface.In this study,four commonly used electrolytes in neutral electrochemical reaction systems were selected,and surface-enhanced infrared absorption spectroelectrochemistry combined with the vibrational Stark effect was used to analyze the special counter-ion effect at the electrode-electrolyte interface.The difference in distributions of anions as counter ions in the electric double layer due to the difference in the strength of the interaction with the electrode surface and the resultant different shielding of the local electric field at the interface were revealed through vibrational Stark probe with different molecular length.Anions that specifically interacted with the electrode could be adsorbed in the Stern layer in large quantities,significantly reducing the local effective electric field.This had far-reaching significance for deep understanding of the electrochemical double layer structure and the structure-activity relationship of the electrocatalytic reaction.At the same time,an effective quantitative analysis method was proposed for analysis of electrode-electrolyte interface.

关 键 词：振动斯塔克效应 表面增强红外光谱电化学 双电层 电极-电解质界面 定量研究 

分 类 号：O657.1[理学—分析化学] O646[理学—化学]