微电极上单核沉积的现场电化学原子力显微镜研究

In-situ Electrochemical Atomic Force Microscopy Studies of Nucleation of Single Nucleus on Microelectrodes

用现场电化学原子力显微镜（ECAFM）观察玻碳微电极上银单核电化学成核与生长的不同阶段的行为．结果表明银单核在玻碳边缘生成以（100）面择优的晶粒，证实了成核过程强烈地依赖于玻碳基底的状态．有成核历史的基底沉积多核，经特殊方法“清洗”的基底沉积单核．本工作中首次把ECAFM应用于微电极系统的研究，对微电极上的单核生长进行实时观察；同非现场测量进行比较，演示一种制备单晶微电极的可行方法．

The electrochemical nucleation and growth of silver single nucleus on glassy car-bon microelectrode have been monitored in-situ with electrochemical atomic force microscopy(ECAFM) at different stages. The AFM results show that the silver single nucleus forms atthe edge of the glassy carbon and grows to form a crystallite with (100) facet preferentiallydominated. It is confirmed that the nucleation process strongly relies on the condition ofglassy carbon substrate. Multiple nuclei are formed on the substrate with nucleation historybut single nucleus can be achieved on the same substrate after the application of a special'purging' method. The work is the first example for the real time observation of nucleationand growth of a single nucleus on a microelectrode and for the application of ECAFM to thestudies of microelectrode systems. Comparison of the work with previous ex-situ measure-ments are given. The work also demonstrates a possible way to obtain a single crystal micro-electrode which c0uld be valuable for various purposes.