Electrochemical impedance spectroscopy measurements were conducted in the frequency range of 100 MHz to 1 Hz (10 points per decade) with a sinusoidal perturbation amplitude of 10 mV (Squidstat Plus, Admiral Instruments, LLC, Tempe, USA). Nyquist plots were fitted with an equivalence circuit (Supporting Information, Figure ) using EC Lab V11.36 to support characterization of solution resistance and charge transfer resistance. In addition to two graphite electrode devices shown in Figure , devices containing reference electrodes were fabricated for a series of membrane tests in different configurations. Titanium electrodes were used as pseudo-reference electrodes. These were created from Titanium wires (Titanium wire 0.25 mm, 99.7% trace metals basis, Sigma-Aldrich, Canada), which were flatted by a hydraulic press (Model M, Carver 4339, Carver Inc., USA). Measurements were conducted in a 10 mM phosphate buffer before and after membrane preparation. The device has two sides, the anode side (Sidea) and the cathode side (Sidec) for each electrode investigation.