EVALUATION OF THE ELECTRO-CATALYTIC OXIDATION OF ASCORBIC ACID, USING A PLATINUM ELECTRODE MODIFIED WITH POLY-3- METHYLTHIOPHENE

Resumo

This study investigated the oxidation of ascorbic acid using a clean platinum electrode coated with a film of poly-3-methylthiophene, called a modified electrode. The films were grown using the chronoamperometric technique and the electrochemical measurements were taken using the cyclic voltammetry technique. We analyzed the anodic peak current and the anodic peak potential using the platinum electrode with and without the film, and in the presence and absence of ascorbic acid. We also investigated the effect of ascorbic acid concentration, the effect of scan rate and the effect of the pH of the solution on the parameters of anodic peak. The results show that the anodic current peak increases and the potential of anodic peak shifts to a more negative value when compared with the clean electrode. We also observed that the anodic peak current increases as the concentration of ascorbic acid, the scan rate and the pH increase. The anodic peak potential shifts to more positive values as the concentration of ascorbic acid and the scan rate increase, while it shifts to more negative values as the pH of the solution increases.