Electrochemical synthesis of a binary Mn-Co oxides decorated graphene nanocomposites for application in nonenzymatic H2O2 sensing

Abstract

In this work, binary metallic oxides of MnO2-Co3O4 nanocomposite was electrodeposited on graphene oxide (GO) modified electrode by a facile and one-step electrochemical method. The resultant MnO2-Co3O4/graphene (MnO2-Co3O4/GP) electrode was characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) to study its morphology and element composition. The as-prepared MnO2-Co3O4/GP modified electrode was employed in fabricating a nonenzymatic H2O2 electrochemical sensor. The cyclic voltammetry (CV) and amperometric experiments demonstrated that the MnO2-Co3O4/GP composites exhibited superior electrocatalytic activities toward oxidation of H2O2 to the monometallic oxide decorated graphene materials (MnO2/GP and Co3O4/GP). The developed nonenzymatic H2O2 sensor showed a high sensitivity of 53.65μA mM-1 cm-2, a wide linear range of 5μM-1.2 mM, and a detection limit of 0.8μM (S/N = 3). In addition, good selectivity, high detection accuracy and acceptable stability were also obtained for the present sensor. Therefore, this work will open an avenue to construct high-performance electrode materials and expand their applications in various fields such as catalysis and biosensor.