General expression of the linear potential sweep voltammogram for a surface redox reaction with interactions between the adsorbed molecules: Applications to modified electrodes

The equation of the linear potential sweep voltammogram is derived for any degree of reversibility of the electrochemical reaction for a surface redox system, when interactions between the adsorbed molecules are present. When the reaction is reversible (k_s/v→∞; k_s: rate of the electrochemical reaction; v=sweep rate), the cathodic and anodic peaks are identical. When the reaction is not reversible the shape of the cathodic and anodic peaks can become widely different, depending on the interaction coefficients. The characteristics of the peaks are studied. Applications to submonolayer adsorption and to redox polymer modified electrodes are discussed.