INVESTIGATION ON ELECTRO CATALYTIC REDUCTION OF OXYGEN IN 2-AMINO-3-CHLORO-1, 4-NAPHTHOQUINONE SOLUTION AT POLYANILINE MODIFIED GCE

Abstract

The oxygen reduction is an important reaction in metal/air batteries, biosensors and fuel cells. The electrocatalyst for oxygen reduction was fabricated by coating poly aniline on glassy carbon electrode (PANI/GCE) with 2-amino-3- chloro-1,4-naphthoquinone (ACNQ) in various buffer solutions of pH 5.0 to 9.0. Cyclic voltammetry, chronoamperometry and chronocoulometric techniques were used to study the electrocatalytic reduction of naphthoquinone as well as oxygen. The stability of the modified electrode was ascertained. The surface morphology of PANI/GCE was examined by atomic force microscopy (AFM). The influence of pH and scan rate on the electrochemical and electrocatalyticbehaviour of the modified electrode was studied and pH 7.0 was chosen as the optimum working pH. The oxygen reduction behaviour of PANI/GCE was compared with that of a bare GCE and the studies reveal that PANI/GCE shows a high electrocatalytic activity towards O2 reduction with the overpotential 583.7 mV. The reduction process proceeds by a two-electron pathway.