Electrochemical Characterization of a Novel Salen-Type Modified Electrode

The nickel(II) complex with H2saltMe, a N2O2 Schiff base ligand derived from salicylaldehyde, was oxidatively electropolymerized on Pt electrodes in CH3CN/0.1 mol dm-3 tetraethylammonium perchlorate (TEAP) to generate polymer films that exhibit reversible oxidative electrochemical behavior in a wide potential range (0.0−1.3 V), high conductivity, and stability/durability. The films of poly[Ni(saltMe)] can be made to exhibit the three regimes of charge transport behavior by manipulation of the film thickness and the experimental time scale. Films prepared by a small number of potential cycles show thin-layer/surface-type cyclic voltammetry behavior in the scan rate range used. Thicker polymers exhibit a changeover from this thin-layer regime to diffusion control at a critical scan rate that depends on film thickness. In chronoamperometry experiments a transition from semiinfinite diffusion to finite diffusion conditions was observed at longer times following the potential step.Values of D1/2C for the secon...