Abstract: The electrochemical behavior of benzyl viologen bication (BV²⁺) on glassy carbn (GC) electrode in phosphate buffer (pH=6.8) was studied by cyclic voltammetry.The redox process of BV²⁺ on unactivated GCelectrodes depends strongly on the concentration of BV²⁺, potential range and scan rates.BV²⁺ ions are reduced in two steps, the neutral viologen deposited on the electrode.On electrochemically activated GCelectrode the adsorption of BV²⁺ is greatlyenhanced, and only adsorbed BV²⁺ shows its redox process in the dilute BV²⁺ solution, however, the adsorbed BV²⁺and BV²⁺ in the solution take part in the electrode process in the concentrated solution.The possible effect of electrochemical activation of GCelectrode was discussed.

Key words: Benzyl viologen, Electrosorption, Glassy carbon, Electrochemical activation