镉电极上的衰减全反射表面增强红外光谱

利用两步“湿法镀膜”方法将ATR-SEIRAS的研究进一步拓展到ⅡB族Cd电极上. 选择吡啶(Py)作为模型分子, 初步比较了Py在不同金属电极表面上的吸附构型.

Attenuated-total-reflection Surface-enhanced Infrared Absorption Spectroscopy on Cadmium Electrode

Surface-enhanced IR absorption spectroscopy in attenuated-total reflection(ATR-SEIRAS) configuration was extended for the first time to a cadmium electrode with the adsorption of pyridine as the model system. The SEIRAS active Cd film electrode was prepared by electrodeposition of Cd mulitlayers onto a underlying Au nanofilm on Si in 0.01 mol/L CdSO_ 4 +0.1 mol/L KClO_ 4. The morphology of the as-prepared Cd film exhibits an island structure. In the potential range of -1.2 to -0.8 V(vs. SCE), only in-plane vibrations belonging to the A_1 symmetry were detected whereas those to the B_1 symmetry virtually were not, suggesting that pyridine coordinates vertically or at a little angle to the Cd electrode surface via its nitrogen end without edge-tilted rotation of its ring plane. The Py adsorption configuration is closed to that found on a Au electrode, but different from that on a Ni or Pt electrode, which may be assigned to different structures of valence electron shells for the substrate metals.