Electrochemical impedance spectroscopy

Electrochemical Impedance Spectroscopy

1. This SOP discusses how to conduct an EIS test on a sample with an isolated, known surface area. This process was originally devised to test the heads of screws with various coating systems.

Safety

• Eye protection should be worn when handling glass.
• Appropriate gloves, chemical PPE should be worn when handling liquids.
• If you using a copper sulfate solution or any other irritant, take care to not spill or expose one's self to the liquid.
• Avoid contact with liquids that have electricity running through them, do not put fingers within the vessel.

Procedure

1. Prepare samples for EIS Testing.
2. Add desired amount of the solution chosen to an electrochemical cell glassware
3. Add a magnetic stirrer
4. Connect the sample to a section of wire.
5. Lower the sample into the electrochemical cell glassware.
6. Position the sample so that the desired area is submerged in the solution.
7. Add the counter electrodes to the glassware
8. add the luggin probe
   • Position the luggin probe close to the sample surface that is being tested
9. Turn the power supply on
10. Connect the power supply wires in the following order
    • WE to the sample wire
    • CE to counter electrode
    • RE to reference electrode
    • SE to the sample wire
11. Run an open circuit potential test, then potentiostatic test, then EIS test using the software.
    • The potentiodynamic test should be -0.5V to 0.5V compared to open circuit

Sample Preparation

• All Samples must have certain requirements to be compatible for EIS testing.
  1. Sample must be a conductive material.
  2. Sample must have an electrical connection to the power supply.
  3. Sample must have all non-conductive material removed at contact point to wire.