Comparative surface electrochemistry of Co and Co3O4 nanoparticles : nitrite as an analytical probe

Abstract

This study described the decoration of edge plane pyrolytic graphite electrode (EPPGE) with synthesised cobalt and cobalt oxide nanoparticles. The modified electrode was characterised by techniques such as TEM, FESEM, XRD, EDS, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The EPPGE-Co demonstrated enhanced electron transport and catalytic efficiency towards nitrite oxidation at pH 7.4 compared with the other electrodes studied. The catalytic rate constant (K) obtained at the EPPGE-Co for nitrite at pH 7.4 is 2.32 x 106 cm3mol-1s-1 while the limits of detection (LoD = 3.3 δ/m) is 7.3 x 10-7 M.