文摘
Pencil lead is composed of clay and graphite and it has been widely used as a low-cost electrode system in electrochemistry. There are a few reports on chemical modification of PGE as oxygen functionalized surface that has been prepared via a pre-anodization technique for electro-analytical applications. For the first time in this work, we introduce a new strategy for electrochemical derivatization of PGE as Prussian blue (PB) and Fe(bpy)32 + functionalized PGEs (i.e., PGE-PB and PGE-Fe(bpy)32 +), utilizing its intrinsic iron (1.31 wt.%), in 0.1 M KCl-HCl medium. Potential cycling of the PGE with Fe(CN)63 − (as solution phase system) and bipyridyl (as surface adsorbed system) resulted in a facile formation of the hybrid complexes on the PGE surface. Physico and electrochemical characterization of PGE-PB and PGE-Fe(bpy)32 + modified electrodes by Raman, FT-IR and UV–Vis spectroscopies, cyclic voltammetry and several control experiments (graphite nano powder, clay, Fe2O3 modified electrodes) evidenced the formation of surface confined complexes on PGE. It was found that the intrinsic iron in clay is responsible for the complexation reactions. Selective electrocatalytic function for the H2O2 reduction reaction was demonstrated as an application of the PGE-PB system.
