| Abstract
| - Acetonitrile and several other common organic solvents have been found to dramatically influence thekinetics of electron transfer and the adsorption at freshly cleaved highly oriented pyrolytic graphite (HOPG).Ferricyanide and anthraquinone-2,6-disulfonate were used to investigate the effect of several pretreatmentprocedures including cleaving, electrochemical pretreatment, and thermal etching on the activity of basalplane HOPG. The results of this work suggest that although active sites produced by cleaving are relativelystable in air and in aqueous solution, exposure to organic solvents quickly and irreversibly passivates themtoward simple outer-sphere electron transfer and adsorption. In contrast, electrochemically pretreatedand thermally etched HOPG is much less sensitive to organic solvents, suggesting that the natures of theactive sites produced by these methods are significantly different. As a result, it is important to take intoaccount this behavior when using freshly cleaved HOPG in surface and electrochemical studies.
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