异烟酸在碱性溶液中金电极上的现场表面增强振动光谱研究

应用表面增强红外吸收光谱法、循环伏安法和微分电容法研究了0.1 mol?L^－1 KClO₄和0.1 mol?L^－1 KCl碱性化溶液(pH 10)中, 异烟酸(INA)在Au电极表面的吸附取向和结构. 结果表明: －0.5～0.2 V (vs. SCE)间INA阴离子(INA^－)通过其羧酸根上的两个氧原子垂直吸附在Au电极表面; 特性吸附Cl^－对上述吸附结构无实质影响. 进一步的表面增强拉曼光谱的测试表明即使在－0.8～－0.5 V, 极少量吸附的INA^－很可能仍维持上述基本构型.

In situ Surface-Enhanced Vibrational Spectroscopies on Isonicotinic Acid Adsorbed on Gold Electrodes in Alkaline Solutions

Surface-enhanced infrared absorption spectroscopy (SEIRAS) in conjunction with cyclic voltammetry and differential capacitance measurement has been applied to investigate the adsorption configuration of isonicotinate (INA^－) species on Au electrodes in alkalinized 0.1 mol?L^－1 KClO₄ and 0.1 mol?L^－1 KCl solutions (pH 10). The results indicate that INA^－ is nearly vertically adsorbed on the Au surface through the two oxygen atoms of its carboxylate group between －0.5 and 0.2 V (vs. SCE). The presence of Cl^－ in a supporting electrolyte dose not change the adsorption configuration of INA^－ on Au electrodes. Further supporting information from surface-enhanced Raman spectroscopy suggests that at negative potentials from －0.8 to －0.5 V, INA^－ species adsorbed on Au electrode of a very low coverage is likely to remain the nearly same configuration as that revealed at more positive potentials.