Reciprocal derivative chronopotentiometry with programmed current: Influence of the reversibility

The behavior of the system Cd+2/Cd(Hg) in the absence and presence of an aliphatic alcohol in noncomplexing media is analyzed in reciprocal derivative and double derivative chronopotentiometry with programmed current (RDCP and RDDCP, respectively). These electrochemical methods have been compared with derivative and double derivative voltammetry (DV and DDV, respectively). When the above system behaves as non reversible, it is not possible to establish a total analogy between chronopotentiometric and voltammetric responses, contrary to the case of a reversible process. The peaks obtained in RDCP are better resolved than those obtained in DV and the different operational principles of RDCP compared to those of DV can reduce its susceptibility to ohmic drop effects. Moreover. RDCP and RDDCP are very versatile in the determination of kinetic parameters of electrode processes since, by varying the current amplitude and/or the power of time u in the programmed current, it is easy to influence the reversibility of the process.