采用现场表面增强拉曼光谱(SERS)研究了4-氰基吡啶在不同pH值下铂电极上的吸附行为。结果表明, pH对4-氰基吡啶的吸附原子没有影响, 均以吡啶环上的氮吸附在电极表面, 但分子的取向不同。酸性条件下, 4-氰基吡啶在正于0. 6V(SCE)的电位区间倾斜吸附, 在0. 6V到-0. 2V以相对垂直方式吸附, 而在负于-0. 4V的电位区间, 分子倾向于平躺吸附; 中性条件下, 在0V附近, 分子由从相对垂直吸附向倾斜吸附转变; 碱性条件下, 分子在可测的整个电位区间内保持近乎垂直的方式吸附在铂电极上。

In situ surface enhanced Raman spectroscopy (SERS) was employed to investigate the adsorption behavior of 4-cyanopyridine on the Pt electrode at different pH values. It was concluded that 4-cyanopyridine adsorbed on the Pt surface via N atom of pyridine ring, which was independent of pH values. However, the molecular orientation was greatly influenced by various pH values. The tilted adsorption configuration is favored in the potential positive than 0. 6Vin acidic solution. It converted to a vertical mode from 0. 6V to-0. 2V. When the potential is moved negatively than -0. 4V, the parallel mode is dominant. In the neutral condition, the orientation would switch from vertical to tilted at ca. 0V. However, it kept vertical mode nearly constant in the alkaline solution during the whole potential region.