Particular time-independent behaviour of the charge–potential and capacitance–potential responses of a quasi-reversible redox monolayer with chronopotentiometry with an exponential current

A general, independent of time and explicit expression for the charge–potential (Q–E) curves of a quasi-reversible electroactive monolayer, corresponding to the application of an exponential current time function of the form I(t) = I0eωt, is presented. This programmed current allows us to treat monolayers of any reversibility degree in a similar simple way to that of the reversible ones. This behaviour can be extended to that corresponding to the capacitance–potential responses (C–E curves). A comparison with the results corresponding to the voltammetric Q–E–t response of non-reversible monolayers when cyclic voltammetry is applied has been carried out. Easy methods for estimating thermodynamic and kinetic parameters of the electroactive film are proposed and experimentally tested by means of its application to the study of the azobenzene reduction at an static mercury electrode in aqueous +1% acetonitrile solutions.