Hello,
I am using a 3-electrode cell for testing ethanol electrooxidation. The reference electrode is Hg/HgO and electrolyte is alkaline KOH. The working electrode and counter electrode are GC and Pt wire respectively.
John Booth from Gamry Technical Support has taught me that I need TO RUN the OCP to check the reference electrode is sound. It should have (+ or -) 100ish mV as the OCP. However, if the OCP is very high or close to (+ or -) 12000 mV, it the reference electrode is most probably due to some air bubble in the reference electrode above the tip at the bottom. This error is persisting with me though I have made sure to fully fill the reference electrode with the filling solution.
I've also calibrated the potentiostat with 2 kOhm dummy cell and is sound which corporate the main problem is more probably with the working electrode.
Any ideas about the actions I should pursue further please?
12 000 mV as OCP is an artifact. If you try to run a voltage measurement with a common voltmeter, but no sample/wire is connected, then the reading will have a continuous drift until the measurement limit is reached (here 12 V is the limit of the voltmeter inside the potentiostat). Thus, 12 000 mV means a broken circuit.
Be sure that some connection inside the electrodes or cables is broken.
Use a common voltmeter (in "diode" mode) to test:
- continuity in GC and Pt electrode and wiring
- a voltage measurement between a pair of electrode (e.g., Pt and REF), you have to record a stable and low value.
For a broken reference electrode: an air bubble inside the electrode behind the frit, some precipitate in the frit, corroded wire inside the electrode are common causes of failure.
- Badges
- Science topic
- Similar topics
- Biological Science
- Kinesiology
- Running