SPLIT SQUARE-WAVE VOLTAMMOGRAMS OF SURFACE REDOX REACTIONS

A fast and simple method for the estimation of kinetic parameters of s urface redox reactions, based on the splitting of their square-wave vo ltammograms, is proposed. A mathematical procedure for simulation of t hese processes is developed. The method can be applied for the fast an d chemically reversible redox reactions which are characterized by the kinetic parameter K greater than or equal to 0.8 (K = k(s)/f). The st andard rate constant, transfer coefficient and standard redox potentia l of the redox reaction of alizarine-red S adsorbed on the mercury ele ctrode in pH 9 medium are k(s) = 60 +/- 10 s(-1), alpha = 0.45 +/- 0.0 3 and E degrees = -0.810 +/- 0.005 V (vs. Ag/AgCl-KCl).