ELECTROCHEMICAL-BEHAVIOR OF MODIFIED ACTIVATED CARBONS IN AQUEOUS ANDNONAQUEOUS SOLUTIONS

Cyclic voltammetric studies of electrodes prepared from unmodified and oxidized activated carbons were carried out, Three kinds of de-ashed commercial carbons were oxidized by treatment with concentrated nitric acid or by beating in air. For all samples the following properties w ere characterized: surface area (S-BET), quality and quantity of surfa ce functionalities and total bonded oxygen. Cyclic voltammograms in aq ueous and nonaqueous solutions (water, acetonitrile, water-acetonitril e mixtures) of electrolytes were recorded. Aqueous solutions with a wi de pH range were used. The relations between cathodic peak potentials and pH values of the electrolyte solutions were estimated. An attempt to characterize the mechanisms of the electrode processes responsible for the formation of these peaks was undertaken.