Skip to content

Electrodes

Jump to bottom
Ben edited this page Aug 9, 2016 · 3 revisions

The Gamry electrostuff box has five leads: white, red, green, blue, and orange.

For all of these procedures, the electrode should be bridged using the 16- or 32-channel bridging plugs and plugged into the working (green) and working sense (blue) leads on the Gamry. Silver chloride wire should be attached to the reference (white) lead, and platinum wire to the counter (red) and counter sense (orange) leads, as pictured here:

The tip of the electrode and the counter and ground wires should be immersed in whatever fluid you are using.

Diagnostics:

These are done in PBS.

Potentiostatic EIS

  • Give the "output file" a useful name
  • Initial Freq. (Hz): 1e6
  • Final Freq. (Hz): 10
  • Points/decade: 10
  • AC Voltage (mV rms): 0.1
  • DC Voltage (V) 0 vs. Eoc
  • All other parameters shouldn't matter.

Cyclic Voltammetry

  • Give the "output file" a useful name
  • Initial E (V): 0 vs Eoc
  • Scan Limit 1 (V): -0.6 vs Eref
  • Scan Limit 2 (V): 0.6 vs Eref
  • Final E (V): 0 vs Eoc
  • Scan Rate (mV/s): seems to work at 49.9999 (?)
  • Step Size (mV): 10
  • Cycles (#): 3
  • I/E Range Mode: Fixed
  • Max Current (mA): 0.005
  • IRComp: None
  • PF Corr. (ohm): 50
  • Equil. Time (s): 10
  • Defaults or whatever you want for the other ones.

Iridium Oxide (IrOx) electrodeposition

This is done in the scary purple fluid

  • It is scary. You may want to wear gloves.
  • Fill a small weigh-boat (the 3-cm ones) with the small phial of fluid (currently marked "new")

This can be done in two stages:

  1. Cyclic Voltammetry
  • Give the "output file" a useful name
  • Initial E (V): 0 vs Eoc
  • Scan Limit 1 (V): -0.05 vs Eref
  • Scan Limit 2 (V): 0.5 vs Eref
  • Final E (V): 0 vs Eoc
  • Scan Rate (mV/s): seems to work at 49.9999 (?)
  • Step Size (mV): 10
  • Cycles (#): 50
  • I/E Range Mode: Fixed
  • Max Current (mA): 0.005
  • IRComp: None
  • PF Corr. (ohm): 50
  • Equil. Time (s): 10
  • Defaults or whatever you want for the other ones.

When you press "Go" it will pop up some warnings (FIXME), which can safely be ignored.

  1. Repeating Chronoamperometry
  • Give the "output file" a useful name
  • Step 1 Voltage (V): 0.5 vs Eref
  • Step 1 Time (s): 0.5
  • Step 2 Voltage (V): -0.05 vs Eref
  • Step 2 Time (s): 0.5
  • Sample Period (s): 0.2
  • Cycles (#): 500
  • I/E Range Mode: Fixed
  • Max Current (mA): 0.1
  • Limit I (mA/cm^2): 1 (but "electrode area" is probably wrong, making this wrong too)
  • IRComp: None
  • PF Corr. (ohm): 50
  • Equil. Time (s): 5
  • The rest as you see fit.

Afterwards, you can transfer the purple fluid back into the bottle.

Immerse the electrode in deionised water for a few seconds to rinse off the excess purple.

Clone this wiki locally