How old r u?

Glad you found it useful :-)

Good question! We work with DC voltages, HOWEVER sometimes we switch the DC from positive to negative. True "AC voltages" switch from +V to -V; whereas our CV experiments switch between V1 and V2. The difference is subtle: - The magnitude of V is constant in AC; so voltage going from +110V to -110V. - In CV, V1 and V2 can have any value, and are not necessarily connected. --- V1 could be +0.5 V , while V2 could be +1.2 V : this would not give an AC condition. --- V1 could be +0.9 V, while V2 could be -0.5 C : while the current would switch direction, it would not have the same magnitude at the extremes of the sweep. True "AC voltages" vary sinusoidally. In our CV experiments, we ramp the voltage linearly up and down, so any wave is more of a saw-tooth rather than a smooth wave.

Glad you have found the videos useful. In the video we first look at the cathode process (reduction of cations to uncharged species) in the example of linear voltammetry; but in the second part when exploring cyclic voltammetry in depth we look at the anode process (oxidation of anions to uncharged species). Note that in both cases they are either oxidised or reduced to the uncharged species - I can't see anywhere that I reference oxidation from the anion direct to cation; this would involve a two-electron process and the kinetics would be _very_ different. Remember that we are only interested in processes happening at one electrode (while a counter electrode completes the circuit); at one potential we will be oxidising anions, and when we lower the potential we will start reducing cations. These are not necessarily positive or negative potentials, simply different levels of potential. We could plan to do our CV sweep between 0.2 V and 1.4V; never going into a negative potential region, but we may still get reduction happening. What we see very much depends on our experimental set up and the system we are interested in. RE 09:23 I'm not sure what you are getting from the video, so not sure where the confusion comes from. The background to the processes is that the negatively charged anion migrates across the electric field gradient to the anode, where it is oxidised to an uncharged species. This then diffuses across the concentration gradient away from the anode. So at point E, the concentration gradient causes diffusion to be faster than the electric field causes for migration of the anions. I realise this is just a re-wording of what I say in the video, so if this doesn't help to clear things up please do let me know.

@@aw_mckinley hey, thank you for the reply. It turns out you are completely right, I assumed the oxidation and reduction examples were for the same compound. At the point E as far as I understand we get a reverse current due to a reduction process and the oxidation has already stopped. I think I assumed the oxidized species are nil at bulk solution so I imagined the diffusion backwards.