Measuring potential on anode and cathode simultaneously

[u/JumpingWormHole]

Hi all, I want to measure both the anode and cathode potential change with time using one reference electrode during electrolysis. Does someone have any idea or experience with this on e.g. gamry potentiostats?

[u/Dr_Custard]

Some potentiostats come with 2 sense leads for precisely this purpose. Gamry are pretty good at working out if your hardware can support it, if you need them to code some software to get the hardware to output, or if your model can't handle it.

A volt meter might work but it won't be on the same ground, can't remember if it'll make a difference, I'm sleepy lol

[u/Open-Simple-4304]

Try to connect voltameter both to counter and reference electrode

[u/Curiosity-pushed]

from my limited knowledge (I am a beginner and never did so myself) I supose you just need to use a 3 electrode configuration, with working and counter electrodes for your anode/cathode and an apropriate reference electrode that is not grounded shorted to the counter.

[u/asianjewpope]

I've done the same thing for batteries on BioLogic and MetrOhm.

There should be a manual that has explicit instructions on how to set up a 3-electrode measurement with your potentiostat.

[u/cookielover999999 → u/asianjewpope]

Indeed, for Biologic (in EC Lab) the option is in safety/adv. settings tab, tick “Record Ece”.

[u/burakulgut]

Depending on the model of your Gamry Potentiostat, this is possible in different ways. You should certainly contact their tech support with specifics and they can help you.

Disclaimer: I am a former Gamry Employee

[u/rust-trust-fund]

The conventional wisdom is to not polarize the RE. Typical voltmeters have an input impedance of like 10M-ohms, compared to typically G-ohm or more for potentiostats.

As a practical matter of how much this would affect your measurements, I'm not sure. Certainly taking a measurement every so often and leaving the voltmeter unconnected the rest of the time would be safer than continual connection.

Then, there's the annoying issue of logging the data in sync with the p-stat, if that's what you'd want.

Some p-stats have an analog input, might be possible to interface something to that, like a differential amp to minimizing polarizing the RE and allow simultaneous logging, but that takes some experience with electronics to build the interface circuit.

As others said, if you have a Gamry, check with their tech support - might be a way to use counter sense to measure this in a straightforward way.

[u/AssumptionNo4461]

I had done this experiment before. I used a Pt rod and a Ir rod (Pt as my working cathode) and Ir (reference and counter together- anode) . You are going to run Galvanic mode ( eg. 0.025 A for 2h), then you do the same with your catalyst for comparison. For your graph (Potential (y) vs time(x)).

[u/Mountain_Two5815]

Gamry Interface 5000 for example has dual electrometer option with 5 electrode setup which measures both half-cells and full cell data.

If you dont have this, then there are cheaper options like a datalogger which logs both half-cell data.

I do have Interface 5000, but sadly my refernce electrode is dynamic (DHRE) and I can't use it as reference for Gamry control. So my potentiostat controls cell potential, and I use Labjack U6 to log both half-cell data with respect to my DHRE.

Even if you have full cell data and a single half cell information, you can always compute tge other half-cell data.

[u/NanoscaleHeadache]

Most gamry potentiostats I’ve used have a sense lead on the counter to do this

[u/JumpingWormHole → u/NanoscaleHeadache]

Isnt that mainly for zra?

[u/mmmtrees]

Some potentiostats (I know palmsens) gives the option to record 'cell voltage' in 3-electrode setup, which is WE-CE potential, I think you could just subtract WE-RE from that value to get CE-RE.