Electrochemical Characterization Techniques: Cyclic Voltammetry, Electrochemical Impedance Spectroscopy, and Stability Testing

Cyclic Voltammetry (CV): Control the voltage scanning range and scanning rate to obtain the corresponding current change curve. The starting voltage is 0 V vs. SHE, and the ending voltage is -1.5 V vs. SHE. The scanning rate is 100 mV/s.
Electrochemical Impedance Spectroscopy (EIS): Under steady-state conditions, a small disturbance is given. By changing the frequency of the AC voltage/current applied to the working electrode (usually a sinusoidal wave), the response signal is obtained to obtain a Nyquist plot. The impedance points where the impedance intersects the X-axis and Y-axis represent the real and imaginary parts of the impedance. The DC potential is selected as -0.7 V vs. SHE, the AC amplitude is 5 mV, and the frequency range is 1000-1 Hz. The shape of the impedance curve can be used to determine whether the electrochemical process is controlled by mass transfer or charge transfer.
Stability Test (I-t): Electrochemically reduce CO2 under constant voltage and record the change curve of current density over time to test the stability of the catalyst. The voltage is -0.7 V vs. SHE, and the time is 3-4 hours.