VOLTAMMETRIC CHARACTERIZATION OF ACTIVATED CARBONS IN MODIFIED CARBON-PASTE ELECTRODES

Carbon paste electrodes (CPEs), modified by the addition of small amounts of finely powdered activated carbon (AC) were studied using cyclic (CV) and square wave voltammetry (SWV). Cyclic voltammograms revealed the expected increase in surface area associated with the presence of the activated carbon but did not reveal any specific redox peaks. Square wave voltammograms of both the modified and unmodified electrodes obtained in acidic solution were characterized by well-defined redox peaks whose behavior was consistent with that expected for couples of the quinone/hydroquinone type. The modified electrodes showed generally larger peaks than the unmodified ones. Regardless of the origin of the activated carbons, the square wave voltammetric response was fairly similar, and it was not possible to confidently differentiate between the different types on this basis.