Electrocatalytic Oxidation of Ascorbic Acid on a Modified Carbon Ceramic Electrode with Carbon Nanotube and Rh(III)terpyridine Complex

A novel chemically modified electrode containing Rh(III)terpyridine complex was achieved on the surface of glass carbon electrode by sol-gel technique. The electrochemical behavior of modified electrode was characterized by cyclic voltammetry in detail. The film electrode obtained was very stable and exhibited electrocatalytic response for oxidation of ascorbic acid. Results showed at bare GC electrode, a small oxidation peak current was observed at about 0.42 V and a well-formed sharp catalytic oxidation peak at about -0.08 V was observed at Rh(III)terpyridine complex modified electrode. The transfer coefficient (?) for electrocatalytic oxidation of ascorbic acid and the diffusion coefficient of this substance under the experimental conditions were also investigated