Non-triangular potential sweep cyclic voltammetry of reversible electron transfer: Experiment meets theory

Conventionally, cyclic voltammetry is performed using triangular waveforms; however, complications can arise from the discontinuity of the capacitive current at the potential vertex in the triangular wave. Recent literature (J. Electroanal. Chem. 2017, 801, 381-387) showed theoretically the opportunities offered by non-triangular waveforms. Herein, we test this theory for the reversible aqueous system [Ru(NH3)(6)](3+/2+) using cosine-based waves at a glassy carbon macroelectrode. The match between the theoretical and experimental results is excellent and offers an alternative and novel method to determine the formal potential E-f degrees of the Ru3+/Ru2+ system. The scan rate dependency of the voltammograms is investigated; and for the cosine wave voltammetry the peak currents are 24% higher than that obtained from the typical triangular waves, coinciding with the simulation results.