Investigation on High Performance of Graphite-Ionic Liquid Paste Electrode: Characterization and New Hypothesis

We report on a graphite-based carbon paste electrode with the ionic liquid n-octylpyridiniun hexafluorophosphate as the binder, and its characterization by electrochemical and optical techniques. Voltammetric sudies reveal that the electrode has attractive features compared to conventional electrodes using paraffin, notably an improved sensitivity and an increased electron transfer rate. Distinct flakes have been identified on the electrode surface that possess sharp edges, randomly interlace together, and appear like mono- and/or multilayer graphene. The attractive electrochemical properties are presumed to result from the presence of mono- and/or multilayer graphenes that are formed during the grinding process and combine with the ionic liquid before they can aggregate as in case of exfoliated flakes. This kind of graphene with its edge plane characteristics provides a particularly high density of electrochemically active sites on the surface of the electrode