Substituent effects on the electrocatalytic oxidation of phenols at preanodized screen-printed carbon electrodes

Preanodized screen-printed carbon electrodes (SPCEs*) lower the oxidation overpotential and improve the peak current of phenols because of the presence of hydroxyl groups on the surface of SPCEs*. These hydroxyl groups can form hydrogen bonds with the OH groups of the phenols. The oxidation peak potential (Epa) is linearly related to the number of hydroxyl groups on the surface of SPCEs*. Moreover, the Epa of phenols at SPCEs* was found to systematically shift depending on the substituents on the phenols. The shifts in the Epa are strongly associated with Hammett’s constant.