How to determine the mass transport limiting current in RDE

[@tomasnavratil1556]

God bless you and this video. Helped me in the moment of desperation.

[@Pineresearch]

You are very welcome, glad it was helpful :)

[@insheee5264]

Thank you so much for the video! but why there is only one pink box for my aftermath? Is there any settings/properties that I need to change?

[@Pineresearch]

What version of AfterMath are you using? Also, sometimes the pink dots overlap, so you need to move one out of the way so you'll see two.

[@insheee5264]

@@Pineresearch I’m using version 1.6.1053

[@Pineresearch]

@@insheee5264 Hmmmmm that's a pretty up to date version. Did you check if the pink dots are overlapping?

[@mennahasan2304]

Thanks for the vide, can we use the same steps for a steady electrode?

[@Pineresearch]

The Levich equation only applies to the mass transport limited current at a rotating disk electrode. If you have a stationary electrode you wouldn't be able to use that formula. Additionally, the shape of the voltammogram would look more like a "Duck" rather than the S-shaped sigmoidal voltammogram in the video. You'd be better off using the Randles-Sevcik equation for the peak current at a stationary electrode to calculate the diffusion coefficient.

[@mennahasan2304]

@@Pineresearch Thank you so much for your reply, what if I want to calculate the diffusion coefficient of a stationary electrode using LSV curve?

[@Pineresearch]

@@mennahasan2304 The Randles-Sevcik equation should be good for determining the diffusion coefficient using LSV. You will need to do a scan rate study with LSV and look at the peak current as a function of the sq rt of the scan rate. you will also need to subtract the background current. But the Randles-Sevcik equation is the best way to calculate the diffusion coefficient using LSV at a stationary electrode. At least to my knowledge.

[@jrath2001]

Great video! How do you find the middle point of voltammogram

[@Pineresearch]

Thank you Jyotisman! We typically eyeball the mid-point of the voltammogram. There might be a better way to mathematically determine the mid-point, but typically I would just approximate where the mid-point is. I don't think you will find too much variation in the mass transport limiting current when you use slightly different mid-points because the slope from both baselines will adjust accordingly. I hope this helps.

[@niteshdogra8306]

A great explanation . Can you help me in finding the overpotential and how to plot the tafel plot ?

[@Pineresearch]

That will definitely go into the que for future videos. Although we have a lot of video ideas we are pursuing.

[@zghelich]

A very good explanation! Could you please make a video on how to calculate the corrosion rate of a metal like Fe through the amount of H2 evolved? Thanks.

[@Pineresearch]

Sorry for the late response. This comment got caught in our "held for review folder." I can put that down as another video topic. Although I do have a long list of video ideas to get through. Thanks for watching!

[@zghelich]

@@Pineresearch Thank you!

[@sebast2530]

Dempsey is my favorite researcher, I would love to collaborate with her.

[@Pineresearch]

She is one of our's too!

[@sebast2530]

@@Pineresearch I recently bought a WaveDriver 40

[@mramezani-fc4ug]

thanks Bud!

[@Pineresearch]

You bet!

[@nugoraqutlimurotova223]

Wonderful

[@Pineresearch]

Thank you! Cheers!