# What does onset of oxidation mean in Cyclic volammetry

I've read a few posts on here on how to calculate onset of oxidations in Cyclic voltammetry. However, I dont know what it actually means when comparing the onsets of oxidations of two different molecules, for example, two conjugated semiconducting polymers.

• I am not an expert on this subject, but my guess is that the onset potential means the voltage at which the activation barrier for the electrochemical reaction is overcome. – S R Maiti Mar 14 at 21:56
• Not really about the onset itself but with conjugated polymers you can have peaks broader than expected due to a distribution of effective conjugation length whatever reason. – Alchimista Mar 15 at 15:00

The concept is explained very nicely here Cyclic voltammetry. I would say the term onset of oxidation is slightly vague but one should talk about $$E_{onset}$$ as shown in the figure. Qualitatively, the current (on the y-axis) begins to rise very fast, that corresponding potential $$E_{onset}$$ tells us that after this potential, the kinetics of oxidation will become appreciably fast.