Similarity of Heterogeneous Kinetics to Delay of Double-Layer Capacitance Using Chronoamperometry

Chronoamperometric curves for the oxidation of a ferrocenyl derivative via potential step, calculated using Cottrell equation, showed less diffusion-controlled currents on platinum wire electrode. This lower deviation cannot be explained Butler–Volmer heterogeneous kinetics, but was ascribed to negatively capacitive current associated with redox reaction. The in fully oxidized electrical corresponds non-zero concentration at electrode surface, which predicted Nernst equation. equation expresses relationship between and activity surface rather than concentration. diffusion determines activity. Negative capacitance or may arise from structure formation owing dipole–dipole interactions, are similar generation double-layer capacitance, including frequency dispersion. Following this concept, we derive expressions lowered time-dependent shows time dependence t−0.9, is decay currents. decays t−0.4-dependence.