ELECTROCHEMICAL CONTORL OF SIGLE ELECTRON TRANSFER AT INTERFACES IN SOLUTION

在外加电场的白光照射下，将银纳米粒子（d =约20 nm）吸附在溶于纯水的玻璃板表面。通过吸收光谱的变化监测溶出度。结构表征表明，由于处理的结果，玻璃上的银纳米颗粒数量减少。然而，经过处理后，颗粒的大小增加到约80纳米。结构的变化率取决于辐照光强度和外电场的存在。结果表明，光激发与溶液中银纳米粒子的电极化相结合，导致了吸附在玻璃板上的银纳米粒子的结构变化。这些变化可归因于金属在银纳米颗粒表面的溶解/沉积的高度局部化电化学反应。采用电化学刻蚀或沉积的方法，在溶液中的可持续性细金线间隙处成功制备了Cu、Ag、Ni、Pd和Pb等金属纳米触点。在Cu， Ag， Ni和Pd的接触处，电导量化表现出相对稳定的单位值行为。与其他金属相比，铅接触的电导量化行为相当不稳定。在该体系中首次观察到室温下Ni、Pd和Pb纳米触点在溶液中的电导量化。

Ag nanoparticles(d = ca. 20 nm) adsorbed on the surface of a glass plate immersed in pure water dissolved when white light was irradiated under application of an external electric field. Dissolution was monitored via change in absorption spectrum. Structural characterization revealed that the number of Ag nanoparticles on the glass decreased as a consequence of the treatment. The size of the particles, however, increased to ca. 80 nm following the treatment. The rate of change in the structure was dependent on both the irradiated light intensity and the existence of an external electric field. The results demonstrate that photo-excitation combined with the electric polarization of Ag nanoparticles in solution leads to structural changes in Ag nanoparticles adsorbed on a glass plate. The changes were attributable to the highly localized electrochemical reactions of metal dissolution/deposition on the surface of the Ag nanoparticles.Metal nano-contacts of Cu, Ag, Ni, Pd and Pb were successfully fabricated via the electrochemical etching or deposition method at a gap of a sustainable thin gold wire in solution. Relatively stable behaviors of the conductance quantization exhibiting a unit value were apparent at the contacts of Cu, Ag, Ni, and Pd. Conductance quantization behavior of the Pb contact was rather unstable in comparison with other metals. The conductance quantization of Ni, Pd and Pb nano-contacts in solution at room temperature was observed for the first time in the present system.