Preconcentration and Electroanalysis of Copper Species at Electrochemically Activated Glassy Carbon Electrodes

Scanning tunneling microscopic and voltammetric studies of the surface structures of an electrochemically activated glassy carbon electrode

The microscopic surface structures of electrochemically activated glassy carbon have been examined by scanning tunneling microscopy. Experimental results demonstrate that there are two different types of electrode surface sites, corresponding to the bundles and bundle edges of the fibrous graphite microcrystallities. Electrochemical activation results in the formation of new void spaces of different sizes, and the structures are affected by the electrochemical activation procedures employed. The void volume resulting from cyclic polarization is usually smaller than that obtained by potentostatic activation. Electrochemical behaviors of the activated electrode are related to both the new void structures and the size of the electroactive species employed. On the basis of the STM voltammetric results, the microscopic structure of the activated electrode is proposed.