吡啶在Au电极上吸附的紫外可见反射光谱法研究

Studies on Adsorption of Pyridine at AU Electrode by Modulated UV/Vis Reflection Spectrometry

电化学调制紫外可见反射光谱技术可用来测定金属电极上吸附物种的取向和吸附物种与金属表面间的相互作用,金属Au与已研究过的Pb、In和Pt具有不同形式的能带结构,吸附物种与电极表面间相互作用的电位依赖性可能不同。本文测定了吡啶分子吸附时Au电极的反射差谱,并试图从能带模型角度探讨吡啶分子与Au电极表面原子间的相互作用。

Both the dependence of relative change in reflectance on potential and the differential reflection spectra for Au electrode in both 0.1 mol/L NaF solution and 0. 1 mol/L NaF, 0. 01 mol/L pyridine solution have been measured respectively. The results show the a new band at 700 nm appeared after the surface atoms of the Au electrode were in a certain oxidized state during anodic polarization. It is assigned to charge-transfer band formed by the adsorbed pyridine molecules and the surface atoms of the Au electrode via the upper full ω-orbitals and the dangling bonds. The band was shiefted to 650 nm after the surface atoms of the Au electrode were in a higher oxidized state due to more anodic polarization.