Electrocatalytic Activity And Electrochemical Impedance Spectroscopy Of Poly(Aniline-Co-Ortho-Phenylenediamine) Modified Electrode On Ascorbic Acid

The poly(aniline-co-ortho-phenylenediamine) modified composite graphite (poly(Ani-co- oPDA)/CG)) has shown excellent electrocatalytic response towards the oxidation of ascorbic acid (AA). The anodic peak potential (E-pa) of AA has shifted from +0.48 V (bare CG) to +0.17 V (poly(Ani-co-oPDA/CG)). The anodic peak currents (I-pa) are linearly dependent upon the square root of scan rate indicating a favourable diffusion controlled process. The electro oxidation of AA on poly(Ani-co-oPDA/CG is more feasible in acidic medium than in either neutral or alkaline medium. This is shown by negative shift of E-pa. The charge transfer resistance (R-ct) at the poly(Ani-co-oPDA/CG) shows that the rate of the electro oxidation of AA changes with electrode potential. The R-ct and diffusion process are dependant not only on applied potential and electrode material but also on the AA.[GRAPHICS]The poly(aniline-co-ortho-phenylenediamine) modified composite graphite (CG) electrode has shown excellent electrocatalytic response towards the oxidation of ascorbic acid (AA). Charge transfer resistance (R-ct) at the poly(Ani-co-oPDA/CG) shows that the rate of the electro oxidation of AA changes with electrode potential.